roject number iec 60079-11 ed7 2018- 11-30 31g/269/cdtk403.ru/pdf/pdf_nats/31g_274eb_cc.pdf · this...

31G/274B/CC

COMPILATION OF COMMENTS ON COMMITTEE DRAFT (CC)

PROJECT NUMBER:

IEC 60079-11 ED7

DATE OF CIRCULATION:

2018-11-30

REFERENCE NUMBER OF THE CD:

31G/269/CD

IEC SC 31G : INTRINSICALLY-SAFE APPARATUS

SECRETARIAT: SECRETARY: CHAIR:

United Kingdom Mr Nicholas Ludlam Mr Manfred Kaiser

OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

FUNCTIONS CONCERNED:

EMC ENVIRONMENT QUALITY ASSURANCE SAFETY

The chair (in cooperation with the secretariat and the project leader) has taken the following course of action:

A A REVISED DRAFT WILL BE DISTRIBUTED AS A COMMITTEE DRAFT FOR VOTE (CDV) BY

B A REVISED DRAFT WILL BE DISTRIBUTED AS A COMMITTEE DRAFT (CD) FOR COMMENT BY

C THE COMMITTEE DRAFT AND COMMENTS WILL BE DISCUSSED AT THE NEXT MEETING ON 2019-03-29

In the case of a proposal A or B made by the chair, P-members objecting to such a proposal shall inform the Central Office with copy to the secretary in writing within 2 months of the circulation of this compilation (see ISO/IEC Directives, Part 1, 2.5.3).

TITLE:

Explosive atmospheres - Part 11: Equipment protection by intrinsic safety "i"

NOTE FROM TC/SC OFFICERS:

The comments received after the deadline from FR are included in this CC.

Annexes: Report of Comments, Comments received

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Report of Comments on 31G/269/CD Circulation Date: 2017-05-12 Closing Date: 2017-08-04 IEC 60079-11 ED7: Explosive atmospheres - Part 11: Equipment protection by intrinsic safety "i"

Country Status Comments Received Australia P Y 2017-08-03 Austria O N 2017-08-03 Belarus - N 2017-08-04 Belgium P N 2017-07-14 Brazil P Y 2017-08-04 Bulgaria O Canada P N 2017-07-24 China P N 2017-07-27 Croatia P N 2017-07-26 Czech Republic O Denmark P Finland P N 2017-08-03 France P N 2017-07-07 Germany P Y 2017-07-31 Greece O N 2017-07-27 Hungary O India O Indonesia O Iran P N 2017-08-04 Ireland O N 2017-05-17 Italy P Y 2017-08-01 Japan P Y 2017-08-02 Kazakhstan - N 2017-08-04 Korea, Republic of P N 2017-07-27 Malaysia P N 2017-08-03 Mexico O N 2017-08-03 Netherlands P N 2017-07-04 New Zealand O Norway P N 2017-08-02 Pakistan O N 2017-07-31 Poland O Y 2017-08-03 Portugal - Y 2017-08-04 Romania P Russian Federation P Y 2017-08-04 Serbia O Singapore O Slovakia O Slovenia - N 2017-07-20 South Africa O Spain P N 2017-07-21 Sweden P Y 2017-07-11 Switzerland P Y 2017-07-26 Ukraine P N 2017-07-29 United Kingdom P Y 2017-08-03 United States of America P Y 2017-07-28

P-members O-members Non-members Total Y : comments

10 1 1 12

N : no comments 13 5 3 21 - : no response 2 10 0 12

Notes P-members with no response: Denmark; Romania *Comments rejected because they were not submitted in the IEC Comment form.

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Date Document Project Nr. 31G/269/CD IEC 60079-11 Ed.7

MB/NC

Line number (e.g. 17)

Clause/ Subclause (e.g. 3.1)

Paragraph/ Figure/ Table/

(e.g. Table 1)

Type of comment

Comments Proposed change Observations of the secretariat

PL-01 - - - ge Very important changes in the standard. In particular in the document organisation. There are also technical changes. The cost of recertification of the existing products will be high.

Noted. Technical changes that affect existing product is being kept to a minimum. All significant technical changes will be listed in the foreword as per TC 31 Good Working Practice. The intent of the reorganization is to limit the differing interpretations of the standard which currently occur, and the MT members consider this benefit to outweigh potential increased cost.

PT-01

ge The Portuguese NC approves the proposed draft. Noted

GB-001

te “normal operation” is used several times in the standard to relate to failures (e.g. the application of Um where that is caused by a failure in the power supply, use of STA for failure of separation etc.). This is in conflict with the 79-0 definition. A statement agreed with the convenor of WG22 is as follows: In Level of Protection “ia” or “ib”, the application of Um or Ui that results in (for example) the opening of a fuse, and the shorting / opening of field wiring, are not normal operation but are expected malfunctions (non-countable faults). In Level of Protection “ic”, the application of Um or Ui that results in (for example) the opening of a fuse, or the shorting / opening of field wiring are considered expected occurrences. The term “expected occurrences” for “ic” with respect to faults Is because “expected malfunction” is specifically excluded for Gc in 79-0. However, this term should be avoided in

Agree to modify the standard accordingly. (There is a separate GB comments for each specific instance).

Accepted in principle See specific proposed changes below.

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(e.g. Table 1)

Type of comment


79-11 so that it does not appear that users should expect their wiring, fuses and non-SELV power supplies to fail.

FR-01

49 Table of contents

ed The name of clause 6.5 doesn’t appear in the table of contents

Automatically refresh the table of contents, or add the line “6.5 Encapsulation”

Accepted

DE-001

348 , 349

0 Foreword ed This seventh edition cancels and replaces the sixth edition of IEC 60079-11 published in 2011. This seventh edition constitutes a technical revision of these publications. Text is a mixture of sentences from previous editions, where several publications (IEC 61241-11, IEC 60079-27) have been combined. Does not fit to the revision of this edition.

Use common sentences via all IEC 60079 standards. e.g. IEC 60079-0, -7, -18, -28 proposed sentence: This seventh edition cancels and replaces the sixth edition published in 2011, and constitutes a technical revision.

Accepted

AU-01

423 1 Ge The title of the Standard is “Equipment protection..” This Clause refers to “intrinsically safe apparatus” and “associated apparatus”. There is a lack of consistency. This is even more apparent when reading line 442 which refers to “equipment” when referring to the subject being dealt by this Standard. We are aware that there is significant history with using the word “apparatus” in relation to intrinsic safety, but we feel that now is the time to bring the nomenclature in line with the rest of the 60079 and 80079 series.

Replace all instances of “intrinsically safe apparatus” with “intrinsically safe equipment” Replace all instances of “associated apparatus” with “associated intrinsically safe equipment”. Replace all instances of “simple apparatus” with “simple intrinsically safe equipment”. Leave the word “apparatus” only when referring to the Spark Test Apparatus.

Not accepted. TC 31 made the decision to retain the term ‘apparatus’ for intrinsically safe devices when other types of protection changed to equipment and the MT does not see any benefit in changing the IS standard now.

AU-02

426 1 2 Ge The standard also applies to equipment containing batteries which may not be intrinsically safe except when isolated from mains power (see 7.11.6).

Add new sentence at end of para 2: This includes equipment that is protected by another Type of Protection, but contains a battery and associated circuits that are intrinsically safe when the mains supply is removed and the enclosure is opened in the explosive atmosphere.

Accepted in principle, made more generic as: This includes electrical equipment which contains circuits which are intrinsically safe only under certain conditions, for example under battery supply with mains supply removed.

AU-04

434 1 Para 4 Te Catalytic elements have been demonstrated to cause ignitions in hydrogen atmospheres with no power applied and no faults applied. Why is this acceptable in an ‘ib’ or ‘ic’ circuit?

Delete “EPL Ga and ” Accepted in principle. Also include Group IIB+H2 and add a note to clarify that other Group IIB gases are fine.

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(e.g. Table 1)

Type of comment


RU-01

434 1 te Since compliance with the requirements of this standard does not guarantee the explosion safety of equipment in which catalytic and other chemical reactions are possible, this has to be specified in the "Scope" section.

To reword the sentence as follows: This standard does not apply to the elements of equipment for EPL Ga and Group IIC where a catalytic or other chemical reaction can result.

Accepted in part. The MT decided that such a generic statement could lead to misinterpretation. For instance, batteries are equipment in which a chemical reaction occurs and this may exclude those.

GB-002

435 1 4th para te Excluding all catalytic elements for EPL Ga and Group IIC is too restrictive as autocatalysis reaction has only been demonstrated for platinum beads. For example, the same ignition tests on Flat Plano Catalytic sensors has not shown this issue.

Replace “catalytic elements” with “catalytic beads or thermos catalytic beads”

Not accepted, research has been presented which demonstrates that all types of platinum catalytic sensors cause ignition of the surrounding atmosphere.

AU-03

444 1 9 Ed This paragraph also appears to restate requirements from paragraph 3 and 60079-0?

Delete paragraph “For associated apparatus placed in the explosive atmosphere, the requirements of the Type of Protection used together with the relevant parts of IEC 60079-0 also apply to the associated apparatus.”

Accepted

GB-007

447 N/A Table 1 ge Table 1 should only show the clauses of IEC 60079-0 that are excluded or modified by IEC 60079-11. This will reduce the size of the table and make it easier to follow. A statement should be made above the table that all clauses of IEC 60079-0 applied with the exception of those listed in Table 1 below.

Table 1 should just list the clauses of IEC 60079-0 that are excluded or modified by IEC 60079-11.

Not accepted, TC 31 Good Working Practice requires listing all clauses. This proposal was reviewed by the GWP committee and decided that all clauses need to be included for clarity.

JP-01 447 1 Table 1 Cl 5.3.4

ed The following description seems to be incorrect. (only for smooth objects greater than 10 000 mm2)

Change the description to: (only for smooth objects not more than 10 000 mm2)

Accepted in principle. Title is normative and is taken from IEC 60079-0 Ed 7. Changed to; “Component temperature of smooth surfaces for Group I or Group II electrical equipment”

JP-02 447 1 Table 1 Cl 5.3.4

te The clause should be applicable also to IEC 60079-11, since there seems to be no technical reason to exclude it.

Change “Excluded” in the Group I/II cell to “Applies”.

Accepted

JP-03 447 1 Table 1 te There seems to be no technical reason to make Change “Applies” in the Associated apparatus cell Accepted

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(e.g. Table 1)

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Cl 6.6.4 the clause applicable to associated apparatus, while other types of radiating source are excluded.

to “Excluded”.

CH-01

447 1 Table 1 on 7.1.2.1

te 7.1.2.refers to the material of enclosures or part of enclosures. In our understanding and in order to avoid confusion, the applicability between 7.1.2.1, 7.1.2.2, 7.1.2.3 and 7.1.2.4 should not be separated from each other. The kind of material (e.g. plastic or metal) might be listed, but this is not what is meant in 7.1.2. The organization of clause 7 in IEC 60079-0 is specifically dedicated to enclosures providing direct explosion protection, which is different in the case of intrinsically safe apparatus. Thus the listing of the kind of material should be listed in 6.1.1, if we consider it to be necessary for the type of explosion protection. Avoidance of electrostatic charges is handled in clause 7.4, where material is not relevant in case the surface meets area limitation requirements. Otherwise the necessary information for the material is part of the assessment in clause 7.4.

Intrinsically safe apparatus: Change “Applies” to “Excluded except when 6.1.2.3 a) is applied.” Associated apparatus: Change “Excluded” to “Excluded except when 6.1.2.3 a) is applied.”

Accepted in principle, further modifications needed to align with changes to text.

JP-04 447 1 Table 1 Cl 7.1.2.1

ed The clause should be applicable only when 6.1.2.3 a) or 6.1.3 a) is applied.

Make the “application” cells same as those of 7.1.1.


DE-002

447 1 Table 1 on 7.1.2.1

te It is not correct, that clause 7.1.2.1 is excluded for associated apparatus because the enclosure of an associated apparatus shall achieve IP20 over its lifetime and need therefore to be specified for the expected environment.

Use same text as on 7.1.2.2 for 7.1.2.1 also. Accepted in principle, further modifications needed to align with changes to text.

DE-003

447 1 Table 1 on 13.1

Ed 1.1 in column 1 instead of 13.1 Correct to 13.1 Accepted

GB-008

447 Table 1 ed 1.1 in column 1 instead of 13.1 Change to: 13.1 Accepted

DE-004

447 1 Table 1 on 14.1 to 14.4

Te IEC 60079-11 gives clear guidance and requirements for connecting facilities. These clauses from IEC 60079-0 should be excluded

Change from “applies” to “excluded” as in 6th Ed. Not accepted. Clause 14 says “Electrical equipment intended for connection to external circuits shall include connection

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(e.g. Table 1)

Type of comment


facilities, with the exception of electrical equipment that is manufactured with a cable permanently connected to it. Connection facilities shall comply with one of the specific types of protection listed in Clause 1. Connection facilities shall be so designed that after proper connection of the conductors, the creepage distances and the clearances comply with the requirements, if any, of the specific Type of Protection concerned.” These apply just as well to i.s. as any other concept.

GB-003

447 14.1 to 14.4 Table 1 te Connection facilities were excluded in 6th edition. Change from “applies” to “excluded” Not accepted See DE-004

JP-05 447 1 Table 1 Cl 14

ed There are requirements in IEC 60079-11 in addition to the clause of IEC 60079-0.

Change all “Applies” to “Modified”. Not accepted See DE-004

US-001

447 Table 1 te IEC 60079-11 Ed 6 excluded IEC 60079-0 Clauses 15 and 16. The CD for IEC 60079-11 Ed 7 now makes those clauses applicable. Is there justification for this change?

Consider aligning these requirements with IEC 60079-11 Ed 6.

Accept in principle. Clause 15 identified as ‘Excluded’ for all columns For Clause 16 see JP-07.

GB-004

447 15.1 to 15.5 Table 1 te In the 6th edition of IEC 60079-11, clause 15 “earthing and bonding” was completely excluded.

Change from “applies” to “excluded” Accepted, see US-001

DE-005

447 1 Table 1 on 15.1 to 15.5

Te In the 6th edition of IEC 60079-11, clause 15 “earthing and bonding” was completely excluded. This makes sense because IS apparatus does not require earthing as other types of protection. When earthing is required as for safety barriers, 79-11 defines the requirements.

Change from “applies” to “excluded” as in 6th Ed. Accepted, see US-001

JP-06 447 1 Table 1 Cl 15

te The clause should apply only to non- intrinsically safe equipment, and should be excluded as it is in the current edition.

Change all “Applies” to “Excluded”. Accepted, see US-001

JP-07 447 1 Table 1 te The clause should be applicable only when Make the “application” cells same as those of Accepted in principle,

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(e.g. Table 1)

Type of comment


Cl 16 6.1.2.3 a) or 6.1.3 a) is applied. 7.1.1. further modifications needed to align with changes to text.

GB-005

447 16.1 to 16.7 Table 1 te In the 6th edition of IEC 60079-11, clause 16 “entries into enclosures” was excluded except when 6.1.2.3 a) was applied. If this is no longer the case, does that now mean all cable glands used for IS apparatus must meet the requirements of Annex A of IEC 60079-0, and must be certified, either as equipment or as integral part of the IS apparatus? Seems a technical change to the previous edition.

Change from “applies” to “excluded” Accepted in principle, excluded except where 6.2.2.3 etc apply.

DE-006

447 1 Table 1 on 16.1 to 16.7

Te In the 6th edition of IEC 60079-11, clause 16 “entries into enclosures” was completely excluded. If this is no longer the case, all cable glands used for IS apparatus must meet the requirements of Annex A of IEC 60079-0, which means they must be certified, either as equipment or as integral part of the IS apparatus. This would be a major technical change to the previous edition

Change from “applies” to “excluded, except where 6.1.2.3 or 6.1.3 was applied, as in 6th Ed.”


JP-08 447 1 Table 1 Cl 22.1

ge The clause should apply, since it would mean caplights and handlights which satisfy only the requirements of IEC 60079-11 are allowed to be used in Group I areas, if it does not apply.

Make the “application” cells same as those of 22.2.

Not accepted. There is a specific standard for Group I caplights: IEC 60079-35-1

DE-007

447 1 Table 1 on 23 all subcl

Ed The battery requirements are written for equipment that will be installed in explosive atmospheres. Associated apparatus will only be installed outside explosive atmospheres. Therefore, the battery requirements from 79-0 are not applicable.

Consider to change from “applies” to “excluded” for the column “associated apparatus”

Not accepted. If batteries are located in associated apparatus and are used to power intrinsically safe apparatus some of these requirements will apply, e.g. maximum voltage

GB-006

447 26.5.1.3 Table 1 te A maximum surface temperature is not relevant for Associated apparatus

Change from “modified” to “excluded” for Associated apparatus column

Not accepted. Based on the PTB run IECEx Proficiency testing, the temperature of components on a board needs to be determined to see if there is any effect on the power rating due to an increase in the local

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(e.g. Table 1)

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ambient adjacent to the safety component.

DE-008

447 1 Table 1 on 26.5.1.3

te A maximum surface temperature for an associated apparatus is not relevant.

Change from “modified” to “excluded” in the last column

Not accepted. Based on the PTB run IECEx Proficiency testing, the temperature of components on a board needs to be determined to see if there is any effect on the power rating due to an increase in the local ambient adjacent to the safety component.

JP-09 447 1 Table 1 Cl 29.7

te The clause should apply also to Group III equipment and associated apparatus protected by multiple types of protection.

Change all “Excluded” to “Applies”. Accepted in Part. Change Group III to ‘Applies’ Add note for Associated apparatus. 60079-11 does not address installation of associated apparatus in a hazardous location, that would be addressed by 79-1, 79-2, 79-18 etc. and the requirements of those standards and 79-0 would apply for the situation proposed.

JP-10 447 1 Table 1 Cl 29.8

te The clause can be applicable to associated apparatus protected by another type of protection.

Change “Excluded” in the Associated apparatus cell to “Applies”.

Not accepted. Because 79-11 only addresses intrinsic safety, “ib” + “ib” does not equal “ia”. The output of any equipment could be suitable for ‘Ga’ but the protection would be two independent Gb protection concepts e.g. db + mb. ‘[ib]’ + ‘mb’, or ‘[ib]’ + ‘db’ do not lead to a Ga protection concept.

JP-11 447 1 Table 1 Cl 29.9

te The clause can be applicable to Group III equipment and also to associated apparatus

Change all “Excluded” to “Applies”. Not accepted. Currently there is no IEC

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(e.g. Table 1)

Type of comment


(Ed. 7.0) protected by another type of protection. standard for a boundary wall condition used for Ga/Gc or Da/Db or Da/Dc. This was raised at the 2016 IEC TC31 meeting in Frankfurt and a task assigned to MT60079-26 to develop a standard. Once a standard has been developed IEC 60079-0 will need to be amended to address this and at that time the Group III column may be changed to ‘Applies’

US-002

447 Table 1 ed IEC 60079-0 Clause 29.13.2 should be excluded for Group I and II, and apply for Group III

IEC 60079-0 Clause 29.13.2 should be excluded for Group I and II, and apply for Group III

Accepted

JP-12 447 1 Table 1 Cl 29.13.2

ed The descriptions in the Group I/II cell and the Group III cell seem incorrect.

Make the descriptions as follows. Group I/II: Excluded Group III: Applies

Accepted

DE-009

447 1 Table 1 on 29.14

te In case that battery requirements are not applicable for associated apparatus, the marking requirement is not applicable as well

Change from “applies” to “excluded” in the last column

Not accepted, see DE-007

DE-010

447 1 Table 1 on 30.2

Ed In case that battery requirements are not applicable for associated apparatus, the instruction requirement is not applicable as well

Change from “applies” to “excluded” in the last column


JP-13 447 1 Table 1 Cl 30.5

te Application of the clause should align with that of 16


Not accepted, this clause gives requirements for the design of cable gland and cable glands should not be designed to 60079-11.

JP-14 447 1 Table 1 Annex A

te Application of the clause should align with that of 16


Not accepted, this clause gives requirements for the design of cable gland and cable glands should not be designed to 60079-11.

DE-011

447 1 Table 1, Annex A

Te Annex A is marked as “Excluded” for associated apparatus, but as applicable, if Annex F is used. If Annex F is used, pollution may come in the apparatus through the cable glands, whether placed inside or outside Ex-atmospheres

Excluded except when 6.1.2.3 a) is applied Not accepted, this clause gives requirements for the design of cable gland and cable glands should not be designed to 60079-11.

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(e.g. Table 1)

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DE-012

449 2 Ed IEC 62013-1 was removed Add again Not accepted as it is no longer referenced.

DE-013

484 2 Ed Correct reference DIN V VDE 0884-11:2017 Accepted in part, date is not necessary. Subject to GB-183

GB-009

486 3 ed These definitions contain symbols (Um etc) and abbreviations (FISCO) so the title should be changed accordingly per DIR-2 2016 17.4

Change title to “Terms, definitions, symbols and abbreviated terms”

Accepted in principle – Structure of Section 3 altered to remove the separate section for abbreviations

GB-010

487 3 ed Add compliance with DIR-2 2016 16.5.2 Add after 1st sentence: ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp

Accepted

GB-011

504 3.1.2 Note 1 ed Associated apparatus outputs may be used in an explosive atmosphere

Replace “used” with “installed” Not accepted, the standard also applies to portable equipment which would not be “installed”, and still may not be used in the explosive atmosphere.

GB-012

507 3.1.3 te When connected in the non-hazardous area, the circuits are not all intrinsically safe.

Add, “Note to entry: circuits completed only in the non-hazardous area are not required to be intrinsically safe”.

Accepted in principle, add to definition: “… whilst in the hazardous area”

GB-013

513 new 3.1.5 te Some requirements relate to “components on which intrinsic safety depends” which is not defined.

Add new definition “components on which intrinsic safety depends” A component which is required by intrinsic safety to meet a specification (e.g. value and rating), and is either deemed to not fail in specified ways, or such failures are countable faults. EXAMPLES: Zener diode, current limiting resistor, safety relevant shunt resistor, all components operating controlled semiconductors such as crowbars.

Not accepted The committee does not think this is a sufficiently clear definition. The definition also needs to apply to ‘ic’ and therefore cannot include reference to failures or countable faults.

US-003

514 3.1.5 ge The definition of simple apparatus states that simple apparatus ‘is compatible with the intrinsic safety of the circuit in which it is used’. The manufacturer of the simple apparatus doesn’t

simple apparatus electrical component or combination of components of simple construction with well-defined electrical parameters and which is

Accepted in principle Changed to: … assessed for use in an

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(e.g. Table 1)

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always know what circuit the simple apparatus will be used in, so doesn’t know if it is compatible or not. The installer is responsible for determining if it is compatible with their or not.

compatible with the intrinsic safety of the circuit in which it is used

intrinsically safe circuit

US-004

524 3.3 ed Defining a diode safety barrier as an associated apparatus, rather than an assembly would be more accurate.

diode safety barrier assemblies associated apparatus incorporating shunt diodes or diode chains (including Zener diodes) protected by fuses or resistors or a combination of these, manufactured as an individual apparatus rather than as part of a larger apparatus

Accepted

GB-014

528, 3177

3.4, 12 a) te “Entity concept” is only used once in this standard, and is not used at all in parts -0, -14 or -25. 3.11 uses the term “intrinsic safety parameters”

Delete entry. In 12 a) replace “electrical parameters for the entity concept” with “intrinsic safety parameters”

Accepted

US-005

534 3.5 ge Using ‘defect’ in the definition of fault implies a deviation from the design of the product. Using ‘failure’ would be better.

fault any defect failure of any component, separation, insulation or connection between components, not defined as infallible by IEC 60079-11, upon which the intrinsic safety of a circuit depends

Accepted in principle, use “failure or malfunction”.

DE-014

537 3.6 te Fuse ratings according to IEC 60127 and ANSI/UL 248 are not comparable. Fuses rated according to IEC 60127 can carry the rated fuse current. Fuses rated according to ANSI/UL 248 cannot carry the rated current. Fuse manufacturers state this in their general product information: The nominal current of an ANSI/UL fuse compared to an IEC fuse is approx. 0,7*In.

This should be taken into consideration Accepted in principle, change definition to: “current rating of a fuse”

GB-015

550 3.8.1 ed “fault mode” is deprecated by IEC 60050 Replace with “failure mode” Accepted

GB-016

566 3.11 te Voltage, current and power parameters can all have brief transients above the stated value. Current wording prohibits that. Requirements are permitted in a note to entry (DIR-2 16.1)

Add: Note 1 to entry: Voltage, current and power at connection facilities may have brief transients above the specified parameter value provided that they do not invalidate intrinsic safety.

Accepted in principle, delete “provided that they do not invalidate intrinsic safety” and replace with “, as permitted by this standard” Similar note added to Um which is now in a different subclause.

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CH-02

569 3.11.1 ed Ui, Ii and Pi parameters are linked to intrinsically safe connection facilities of the apparatus. This wording has been added to the definitions of Ii and Pi, but were not transferred to the definition of Ui.

Change to Ui maximum voltage (peak a.c. or d.c.) that can be applied to the intrinsically safe connection facilities of apparatus without invalidating intrinsic safety

Accepted in principle, see also AU-05

SE-01

574-576 3.11.2 Ed Align the wording with the definition of maximum input power Pi according to 3.11.3.

Delete some words according to the following, for the alignment: “maximum current (peak a.c. or d.c.) for the intrinsically safe connection facilities of the apparatus, that can be taken from external circuits connected to the connection facilities of apparatus without invalidating intrinsic safety.


JP-15 575 3.11.2 ed The description should align with that of 3.11.3. Remove “of apparatus” from the following part. …external circuits connected to the connection facilities of apparatus without …


SE-02

597 3.11.6 Ed Delete “external” to align the definition with the other parameter definitions.

Delete “external” according to the following: “ …appearing at the intrinsically safe external connection facilities”

Accepted

DE-015

601 -602

3.11.7 Ed Delete the end of the definition …at any voltage up to the maximum voltage This is a condition or requirement that is not explained and does not add clarity to the definition

Remain with: Maximum voltage (peak a.c. or d.c.) that can appear at the intrinsically safe connection facilities

Accepted

AU-05

602 3.11.7 1 Ed The present definition does not align with the definition for Io and the reference to “maximum” voltage in the definition for maximum output voltage is unclear. The definition can also be unclear where there is a DC offset in an AC output, and simply referring to the “peak” voltage rather than “peak ac or dc” helps to clarify this.

Delete “at any applied voltage up to the maximum voltage” and revise text to simply: “maximum (peak) voltage that can appear at the intrinsically safe connection facilities of the equipment”

Accepted in principle, also applied to Ui

AU-06

603 3.11.8 Ed The definition can be unclear where there is a DC offset in an AC output, and simply referring to the “peak” current rather than “peak ac or dc” helps to clarify this.

Change “maximum current (peak a.c. or d.c.)” to “maximum (peak) current”

Accepted in principle, also applied to Ii

US-006

606 3.11.8 ed Remove ‘in apparatus’ from the middle of the definition.

Remove ‘in apparatus’ from the middle of the definition.

Accepted

CH-03

628 3.11.13 ed 3.11 provides the definitions for intrinsically safe parameters. Um is not considered to be an

Change to Accepted

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(e.g. Table 1)

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intrinsically safe parameter, but a specific voltage condition on the non-intrinsically safe circuit. By changing the header for 3.11 from “electrical parameters” to “intrinsic safety parameters”, the definition of Um should have a separate number.

3.12 Maximum r.m.s a.c. or d.c. voltage Um ………. Increase numbers for following definitions.

GB-017

631 3.11.13 te Um does not apply to the intrinsically safe connection facilities of associated apparatus. Note: “non-intrinsically safe” has been removed since Ed.6, it should go back in again. 6.2.5 requires the use of Um to define the voltage for non-hazardous area connection facilities of IS apparatus. The first part of Note to entry 1 is part of the definition so should not be a note. The second part is an example.

Modify text: maximum voltage that can be applied to the non intrinsically safe connection facilities of associated apparatus, and to the connection facilities of intrinsically safe apparatus for use only in the non-hazardous area without invalidating the type of protection Note 1 to entry: This additionally applies to the maximum voltage that can be applied connection facilities of intrinsically safe apparatus when located in a non-hazardous area (for example, charging connections on battery operated apparatus, where charging is only done in the non-hazardous area). EXAMPLE: Examples of non-hazardous area only connection facilities of intrinsically safe apparatus are battery charging contacts and data interfaces.

Accepted in principle, change ‘and’ to ‘or’ and make grammatical correction.

CH-04

3.11.13 ed If requirements in this standard are applicable to both intrinsically safe apparatus and associated apparatus the term “apparatus” is used throughout the standard (see Note 1 and line 440 of this standard).

Change to maximum r.m.s. a.c. or d.c. voltage Um maximum voltage that can be applied to the connection facilities of apparatus without invalidating intrinsic safety

Accepted in principle, see GB-017.

GB-018

637 3.11.13 te The application of Um can be the result of a fault in the power supply (e.g. for a fuse protected Zener barrier) See GB comment on “normal operation”.

Add note: NOTE 2 to entry The application of Um can be the result of a fault in the power supply and hence outside normal operation.

Not accepted, Um also applies to ‘ic’ where faults are not applied. See also GB-001

DE-016

638 -644

3.12 Ed Use the same terminology as in the referred source document.

3.12 PELV system electric system in which the voltage cannot exceed the value of extra-low voltage: – under normal conditions, and – under single fault conditions, except earth faults in other electric circuits

Accepted in principle. Altered to align with TC31 WG22 and TC1 input

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Note – PELV is the abbreviation for protective extra-low voltage. [SOURCE IEC 60050-826, 826-12-32]

JP-16 639 640

3.12 ge The terms do not match the definition. Change the terms as follows. protective extra-low voltage system PELV system

Accepted in part, see DE-016

DE-017

646 -652

3.13 Ed Use the same terminology as in the referred source document. Source is: IEC 60050-826

3.13 SELV system electric system in which the voltage cannot exceed the value of extra-low voltage: – under normal conditions, and – under single fault conditions, including earth faults in other electric circuits Note – SELV is the abbreviation for safety extra-low voltage. [SOURCE IEC 60050-826, 826-12-31]

Accepted in principle. Altered to align with TC31 WG22 and TC1 input

JP-17 647 648

3.13 ge The terms do not match the definition. Change the terms as follows. safety extra-low voltage system SELV system

Accepted in part, see DE-017

DE-018

656 -659

3.14 ed Why describing a process? Remove the note, too.

Moulding partially or completely encapsulate a component in a reproducible way with a determinable thickness of plastic material

Not accepted, as the term moulding is used to refer to the process.

CH-05

660 3.15 te As note 1 refers to circuits and components, the normative text should also address circuits and components. We assume it possible to use the term shunt safety assembly in a more generic way, because safety shunts allow also current limitation into an energy storing component or other and safety shunts are not limited to resistors and semiconductors.

Change to 3.15 Shunt safety assembly assembly of components which ensures intrinsic safety of a circuit or components by the utilization of shunt components. Note 1 to entry: Shunts may be resistors, semiconductors or other components safely diverting the current or limiting the voltage in an intrinsically safe circuit or in a protected component.

Accepted

GB-019

661 3.15 ed “Shunt” is not a proper noun Change upper case “S” to lower case “s” in title Accepted

JP-18 665 3.15 Note 1 te The description seems to limit the use of shunt safety assembly to those used in intrinsically safe circuits.

Change “limiting the voltage in an intrinsically safe circuit” to “limiting the voltage of an intrinsically safe circuit”.

Accepted in principle, see CH-05

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GB-020

666 3.16 ed “Spark” is not a proper name Change upper case “S” to lower case “s” in title Accepted

DE-019

666 3.16 Ed “line break” after clause number missing Accepted

DE-020

667 3.16 ed What is the meaning of this? Delete text in brackets Accepted, clarification of domain is not necessary.

GB-021

668 3.16 ed Inconsistent use of indefinite article Delete “an” Accepted

GB-022

670 3.17 ed Use definition for EDLC capacitors instead of supercapacitor (see below)

Change to: electric double-layer capacitor capacitor device that stores electrical energy using a double layer in an electrochemical cell, and its positive and negative electrodes are of the same material Note 1 to entry: The electrolytic capacitor is not included in capacitor of this document

Accepted in principle, replace entire definition with 60050-114-03-03

JP-19 672 3.17 te “high capacity” is rather ambiguous and may cause different interpretations.

Make the definition as follows. device that stores electrical energy using a double layer in an electrochemical cell [SOURCE: IEC 60050-114-03-03]

Accepted in principle, replace entire definition with 60050-114-03-03

CH-06

680 3.18.1 Note 1 ed Data sheets rarely provide transient ratings, but parameters allowing a judgement on the resistance of the component against transient effects. The description should be more open. For example, if a peak non-repetitive surge current is good enough, a peat repetitive surge current should suit the need. We would appreciate to describe what is meant first and to add the examples after that.

Change Note 1 to Note 1 to entry: Meant are component pararmeters which allow a judgement on the resistance of the component against transient effects. I2t values and peak-surge currents can be looked at as two examples of a variety of parameters.

Not accepted, the definition is already very open and the note only provides examples. Based on TG discussion it is more consistent with most datasheets to wordsmith it to EXAMPLES: I2t value and non-repetitive peak current.

GB-023

680 3.18.1 Note ed Note provides examples so should use appropriate format.

Replace “Note 1 to entry:” with “EXAMPLE” Accepted

GB-024

684 3.18.2 Note ed Note references examples so should use appropriate format.

Replace with: EXAMPLE: Annex D contains examples.

Accepted in part, replace with: "Annex D gives examples of how to measure transient energy"

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Note that TG also working on a proposal to add a test to cover 7.4.1 in Annex D (by MK)

US-007

685 3.18.3 (7.6.3 7.6.5 9.1.5.3)

ge Using nominal operating voltage in the definition of transient voltage can be misleading. In many circuits the nominal operating voltage is below the rated voltage of the voltage limiting devices relied on for I.S. The transient voltage is the let-through voltage of those voltage limiting devices. (Throughout the standard the terms ‘transient’ and ‘let-through’ are used interchangeably, and inconsistently. Using ‘let-through’ may be better, as to not imply transients associated with mains overvoltage categories.)

a short duration voltage above nominal operating voltage rated voltage of the voltage limiting devices that occurs within the circuit as a result of applying faults or with when Um or Ui is initially applied

Not accepted, definition deleted as it is used only once.

GB-025

687 3.18.3 ed Inconsistent use of indefinite article, improve wording.

Modify text: a short duration voltage above nominal operating voltage that occurs within the circuit as a result of applying faults, or with Um or Ui applied as applicable


GB-026

687-688 3.18.3 1st Paragraph

te Transient voltages may occur without faults or at least the transient voltage should not be considered as a countable fault.

Change to: “a short duration voltage above nominal operating voltage that occurs within the circuit”


IT-01 690 4 ed/te Clause 4 is misleading. It seems that an associated apparatus when additionally protected by another type of protection shall be marked with the gas group and temperature class. Modify as proposed.

Intrinsically safe apparatus shall be grouped ……. requirements of IEC 60079-0. When an associated apparatus is additionally protected by ………explosive atmosphere, the whole shall be grouped in accordance with …… of IEC 60079-0.

Accepted in principle, change all of clause 4 to: Intrinsically safe apparatus and intrinsically safe parts of associated apparatus shall be grouped in accordance with equipment grouping requirements of IEC 60079-0. Intrinsically safe apparatus shall have a maximum surface temperature or temperature class assigned in accordance with the temperature requirements of IEC 60079-0. Note: Equipment containing associated

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apparatus protected by another Type of Protection will be assigned temperature class and equipment group according to the requirements of that Type of Protection.

DE-021

692 4 1st para Ed It should say “intrinsically safe apparatus” Add “apparatus” Accepted

CH-07

692 4 ed Word “apparatus” is missing Add the word “apparatus”: Intrinsically safe apparatus shall be grouped …..

Accepted

GB-027

692 4 1st Paragraph

ed. “apparatus” missing Change to: “Intrinsically safe apparatus shall….” Accepted

AU-07

692 4 1 ed Missing noun Modify the text: Intrinsically safe equipment shall be grouped in accordance with equipment grouping requirements of IEC 60079-0 and shall have a maximum surface temperature or temperature class assigned in accordance with the temperature requirements of IEC 60079-0

Accepted in principle, see AU-01 and DE-021.

US-008

692 4 ed Intrinsically safe itself can’t be grouped. Intrinsically safe apparatus and intrinsically safe parts of associated apparatus shall be grouped…

Accepted in principle, see IT-01

FR-02

692 4 1st ed The word “apparatus” is missing at the beginning of the 1st sentence

Correct the beginning of the 1st sentence: “Intrinsically safe apparatus shall be grouped in accordance with…”

Accepted

CH-08

699 4 te Environmental influences are addressed in clause 5 of IEC 60079-0 and in clause 6 of this standard. In our understanding these requirements apply to intrinsically safe apparatus and associated apparatus. It might be misleading addressing this point in relation to associated apparatus only. We have not seen the need to address the requirements additionally in clause 4.

Remove the wording “and environmental influences” in the 3rd sentence. Associated apparatus which is not additionally protected by a Type of Protection listed in IEC 60079-0 shall be grouped in accordance with the equipment grouping requirements of IEC 60079-0.

Accepted in principle, paragraph deleted.

DE-022

700 4 2nd para Te What are these environmental influences requirements” in 60079-0?

delete added words and bring back to previous text. …

Accepted in principle, paragraph deleted.

US-009

704 5.1 ed ‘…shall be placed in…’ could be worded better. ‘…shall be certified as…’ or ‘…shall be assigned a…’

Accepted 2nd suggestion as in line with 79-0

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CH-09

708 5.1 2nd pargph. Ed Clause 6.4 addresses internal connections. We would appreciate to find the term “internal” in the 2nd sentence in the 2nd paragraph.

Add “internal” in the 2nd sentence. … In the determination of Level of Protection “ia", "ib" or “ic”, failure of separations between conductive parts shall be considered in accordance with 6.3, failure of internal connections shall be considered in accordance with 6.4 and failure of components 709 shall be considered in accordance with Clause 7.

Accepted

GB-028

715 5.1 3rd para ed “fault mode” is deprecated by IEC 60050 Replace with “failure mode” Accepted

GB-029

716 5.1 4th para te Failure of separation is not normal operation (See GB comment on “normal operation”. This sentence is specific to spark ignition compliance so should have been in 5.3 anyway.

Delete paragraph. See also proposed revised 5.3 (Annex GB-1).

Accepted in principle, change as: Note: Insertion of the spark test apparatus under the conditions specified is a test and is not considered an additional fault.

CH-10

716 5.1 4th pargph. In 9.1.2 2nd, 3rd, and 4th paragraph the appropriate use of the spark test apparatus is described, including the differentiation between ia, ib and ic. The information seems to be redundant. We assume the more detailed information in clause 9.1.2 to be sufficient.

Delete the following sentence: Insertion of the spark test apparatus under the conditions specified in this standard shall not be considered as a countable fault but as a test in normal operation as applicable


GB-030

718 5.1 5th para ed “Intrinsic safety parameters” is the term used in 3.11.

Replace “intrinsically safe parameters” with “intrinsic safety parameters”.

Accepted

GB-031

721 5.1 6th para te This paragraph referencing SELV and PELV states that Um is only applied as common mode. That is not stated in 3.11.13, nor is it currently how equipment is normally assessed. This is also not consistent with IEC 60079-14 which states that SELV and PELV can be used to reduce Um < 250Vac. As per the discussion of the note in Ed.6 6.2.5, this is not directly related to the design or assessment of equipment, but is an installation issue.

Delete paragraph and example. Not accepted 3.11.13 provides the definition of Um, but paragraph 5.1 gives an indication of how the voltage of a circuit not necessarily related to earth should be used for an assessment of an associated apparatus. This appears to be a design requirement for the product.

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DE-023

721 5.1 6th para Ed Non-IS connection facilities of associated apparatus can be connected to SELV or PELV systems (not circuits). Use the terminology defined in the IEV and in definitions 3.12 and 3.13

Reword the clause as follows: For circuits of associated apparatus which are connected to SELV or PELV systems, Um shall…

Accepted in principle, further reworded for clarity

CH-11

721 5.1 6th pargph. The examples given classify explicitly the type of circuits. Wouldn’t it be useful to reflect this circumstance in the normative text as well?

Add the word “signal” For signal circuits of associated apparatus which are connected to safety extra low-voltage circuits …

Not accepted MT has not considered the 6th paragraph to be limited to signal circuits only.

DE-024

723 5.1 te “Nominal operating voltage” applied maybe lead to misinterpreting. See terms and definitions “new”

For circuits of associated apparatus which are connected to safety extra low-voltage systems (SELV) or protective extra low-voltage systems (PELV), Um shall only be applied as a ‘common mode’ voltage for these connections, for the differential mode voltage between these connections, only the operating voltage (nominal voltage with tolerances or voltage range) shall be applied. Um and the operating voltage shall be specified by the manufacturer, and these values shall be detailed in the documentation.

Accepted in part MT is aware that nominal voltage might be a voltage range, but does not see the necessity to be more specific in the text of the standard. For circuits of associated apparatus which are connected to safety extra low-voltage systems (SELV) or protective extra low-voltage systems (PELV): Um shall only be applied as a ‘common mode’ voltage for these connections and the nominal voltage shall only be applied for for the differential mode voltage between these connections. Um and the nominal voltage shall be specified by the manufacturer, and these values shall be detailed in the documentation.

DE-025

727 5.1 EXAMPLE ed The listed examples are not generally SELV or PELV, while other circuit may conform but are not listed. This is misleading!

Delete the example Accepted, examples deleted. For 2nd CD, TG considers

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the possibility to change “SELV, PELV” to non-shock hazardous circuits galvanically isolated from mains in accordance with an industrial standard (e.g. SELV, PELV, …). Not all non-shock hazardous circuits are classified SELV or PELV though they fulfil the requirements we would like to address in this standard.

DE-026

728 5.1 7th para Ed Use “systems” instead of circuits The certificate number for associated apparatus relying on SELV or PELV systems shall…

Accepted

GB-032

728 5.1 7th para te SELV and PELV is not the only means of obtaining Um < 250Vac (per IEC 60079-14).

Replace “The certificate number for associated apparatus relying on SELV or PELV circuits” with “Associated apparatus where Um is less than 250 Vac (e.g. for supply from SELV and PELV power supplies),”

Not accepted This would lead to the situation where all associated apparatus with Um < 250 V gets an X condition. TG does not see any reason why this would be needed because IEC 60079-14 gives sufficient information what to consider in this case.

GB-033

734 5.1 Last sentence

te The application of Um or Ui might be the result of a failure in the connected equipment which is not normal operation See GB-01 comment on normal operation.

Delete sentence. Accepted

CH-12

734 5.1 The sentence “The application of Um or Ui is considered normal operation” might be misleading, if not brought into relation with the assessment in accordance with this standard. Example: a non-intrinsically input circuit of an associated apparatus with a nominal voltage of 24 V and a Um = 250 V is designed based on the nominal voltage UN = 24 V, except for the components and parts of the circuits, which are relevant for intrinsic safety (e.g. fuse, galvanic isolation, …), where the assessment is based on

Change to In the terms of clause 5.2, the application of Um or Ui is considered normal operation.


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Um = 250 V.

IT-02 734 5.1 te “The application of Um and Ui is considered normal operation”. The sentence may create confusion because Um and Ui do not appear in normal operation.

Remove the sentence as application of Um and Ui is already covered in 5.2.1, 5.2.2 and 5.2.3.

Accepted

AU-08

735 5.1 Note 1 Ge Present note limits itself to equipment with more than one level of protection having different parameters for the different levels. However, there are many cases where the equipment has more than one Gas Group hence having different parameters for the different groups. Also, equipment having more different parameters for the different temperature classes.

Expand note 1 as follows: “Apparatus may be specified with more than one Level of Protection, more than one Group and more than one Temperature Class, and may have different parameters for these varied cases”

Accepted in principle, reworded slightly.

AU-09

735 5.1 Note 1 Ed Permissions contained within a note. Make normative text. Accepted

GB-034

735 5.1 Note te “May” is permission and should not be used in a note.

Change to normative text. Accepted

GB-035

739 5.2.1 te The wording makes no sense when the application of Um is not normal operation (e.g. fuse protected Zener barriers). Similarly, it is not possible to have normal operation and faults at the same time. See GB-01 comment on “normal operation”. “electrical” is superfluous (see Scope) “may” is permission (DIR-2). “if the test requirements for "ia" can then be satisfied” is superfluous as that is covered by “shall not be capable of causing ignition”.

Modify text: With any voltage up to Um or Ui applied as applicable, the intrinsically safe circuits in electrical equipment of level of protection "ia" shall not be capable of causing ignition in each of the following circumstances: a) in normal operation; a) in normal operation and b) with the application of those non-countable faults which result in the most onerous condition; b) in normal operation and c) with the application of one countable fault plus those non-countable faults which result in the most onerous condition; c) in normal operation and d) with the application of two countable faults plus those non-countable faults which result in the most onerous condition. The non-countable faults applied may can differ in each of the above circumstances. In testing or assessing the circuits for spark ignition, the following safety factors shall be applied in accordance with 9.1.4.2: – for both a), b) and bc) 1,5 – for cd) 1,0

Accepted in principle, replace “in normal operation” with “under the most onerous conditions with no faults applied”.

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The safety factor applied to voltage or current for determination of surface temperature classification shall be 1,0 in all cases. If only one countable fault can occur, the requirements of a) and bd) shall be considered to be met by requirements of c).give a level of protection of "ia" if the test requirements for "ia" can then be satisfied. If no countable faults can occur the requirements of ac) and d) shall be considered to be met by the requirements of b)give a level of protection of "ia" if the test requirements for "ia" can then be satisfied.

DE-027

739 5.2.1 1st para Ed The sentence may be misinterpreted because it is not obvious whether the IS circuit or the electrical equipment is of Level of Protection “ia”.

Re-write as follows: With any voltage up to Um or Ui applied to the apparatus, the intrinsically safe circuits in Level of Protection “ia” shall not be capable of causing ignition in each of the following circumstances:

Accepted in principle, change as: … Um or Ui as applicable applied to the connection facilities of the apparatus …

DE-028

753 5.2.1 ed Important fact first For determination of surface temperatures (surface temperature classification) a SF of 1.0 shall be applied to voltage and/or current in all cases.

Accepted in part, modified to: For determination of maximum surface temperature, a safety factor of 1,0 shall be applied to voltage and current. 5.2.2 also modified accordingly.

GB-036

760 5.2.2 te GB comments relating to working of 5.2.1 apply equally to 5.2.2.

Modify 5.2.2 along the same lines as 5.2.1. Accepted

DE-029

760 5.2.2 1st para Ed The sentence may be misinterpreted because it is not obvious whether the IS circuit or the electrical equipment is of Level of Protection “Ib”.

Re-write as follows: With any voltage up to Um or Ui applied to the apparatus, the intrinsically safe circuits in Level of Protection “ib” shall not be capable of causing ignition in each of the following circumstances:


CH-13

772 5.2.2 ed Harmonization of wording between 5.2.1 and 5.2.2

Add the word “then” If no countable fault can occur the requirements of a) shall be considered to give a Level of Protection of “ib” if the test requirements for “ib” can then be

Accepted in principle, wording further clarified

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satisfied.

DE-030

774 5.2.3 1st para Ed The sentence may be misinterpreted because it is not obvious whether the IS circuit or the electrical equipment is of Level of Protection “Ic”.

Re-write as follows: With any voltage up to Um or Ui applied to the apparatus, the intrinsically safe circuits in Level of Protection “ic” shall not be capable of causing ignition in each of the following circumstances.


GB-037

774 5.2.3 1st sentence te The wording makes no sense when the application of Um is not normal operation (e.g. when normal operation is 12V but Um=250Vac so that a non-assessed power supply can be used). See GB comment on “normal operation”.

Modify 1st paragraph: In both normal operation and with any voltage up to Um or Ui applied as applicable, the intrinsically safe circuits in electrical equipment of level of protection "ic" shall not be capable of causing ignition in normal operation and under the conditions specified in this standard.

Accepted in principle, sentence modified to remove reference to normal operation as has been done for ‘ia’ and ‘ib’.

GB-038

776 5.2.3 1st para te “under the conditions specified in this standard” is confusing, not least because this requirement is not present in 5.2.1 and 5.2.2.

Delete “under the conditions specified in this standard”

Accepted

DE-031

781 5.2.3 Last Para Ed “clause” at wrong position “See 6.3 and clause 7”.

Change to “See clause 6.3 and 7.” Not accepted, according to DIR-2, 6.3 is a subclause and 7 a clause.

SE-03

781 5.2.3 Ed Clarify that short-circuits shall be considered for certain separation distances according to 6.3.2.3 and 6.3.2.5.

Amend the para to read: “ …failure of components and connections is not considered. However, short-circuit of certain separation distances shall be considered, see 6.3 and clause 7…”

Accepted in part, see AU-11.

AU-10

782 5.2.3 3 Te This paragraph is presently confusing, removing the double negative may help clarify.

Change last sentence to: Components on which intrinsic safety depends shall only be used within ratings as required by the standard.

Accepted in part, modified to: Components on which intrinsic safety depends shall only be used within their rating as required by this standard.

AU-11

782 5.2.3 3 Te Text to finish resolving comment US-025 in 31G/267/INF.

Add note to end of clause: Note 1: For level of protection “ic”, the concept of “components on which intrinsic safety depends” is only applicable in assessing spark ignition compliance.

Accepted in part. A Compromise “ic” solution task group was formed to consider the 31G/278/INF comments on 31G/277/DC, and draft a proposed compromise solution for presentation during the MT 60079-11 meeting in Split

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(Croatia). This solution was proposed and discussed by the maintenance team. As a result, 5.2.3 was revised accordingly.”

GB-039

782 5.2.3 Last para ed The set of values is a “rating” according to 79-0. Change “within ratings” to “within their rating” Accepted

GB-040

782 5.2.3 Last para ed Which standard? Replace “the standard” with “this standard”. Accepted

GB-041

783 5.2.4 (new) te It is not explained anywhere that the conditions of 5.2 include the most onerous manufacturing variations (other than Table 9 for resistors attempts this). Permission is required to allow use of absolute maxima and minima as some certification bodies insist on only nominal values plus tolerance.

Add subclause: 5.2.4 Manufacturing variation In the assessment of the application of the conditions of 5.2.1, 5.2.2 and 5.2.3, the most onerous values resulting from the manufacturing process shall be taken into account. These might be different in each case considered. For components for which countable or non-countable faults are not applied in any case, the tolerance on values specified by the manufacturer may be assumed. Alternatively, the manufacture for the equipment may specify absolute maxima or minima (as applicable) which are assured by the manufacturing process. EXAMPLES: - for the purposes of assessment, the

manufacturer uses an absolute minimum value of resistance for a resistor on which intrinsic safety depends. Then in production, there can be variation in the nominal value of resistor used without further assessment provided that the nominal value less the tolerance is at least the absolute minimum used for the assessment.

- components are selected on routine tests following measurement of their value..

Accepted in Principle, reworded and added as clause 7.3.

GB-043

787 5.3 2nd sentence

te 9.1 contains details of assessments and other spark ignition requirements. These should be located here rather than in the test clause.

See proposed new text in Annex GB-1. See comment on 9.1.1 & 9.1.2 for removal of text.

Accepted in principle, text has undergone further development.

GB-042

784 5.3 te One of the main parts of the standard is the prevention of ignition by a spark due to capacitive inductive or quasi inductive effects, yet this is

Add reference to Annex A for spark ignition assessments.

Accepted in principle, Annex A assessment procedure mostly relocated

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addressed in a mere four lines in the standard with reference to testing ‘if necessary’. Assessment is addressed in more detail in Annex A, but this is not referred to from 5.3. The only reference is to 9.1 which is in the verifications and tests section.

into this clause and 9.1.

CH-14

785 5.3 te Only intrinsically safe circuits that come into contact with explosive atmospheres shall be assessed and/or tested to ensure that available spark energy is incapable of causing ignition at each point where an interruption or interconnection can occur. Adding the wording “that come into contact with explosive atmospheres” aligns the assessment description for spark ignition compliance and thermal ignition compliance, where we already find the differentiation between Group I & II and Group III.

Change to Intrinsically safe circuits that come into contact with explosive atmospheres shall be assessed and/or tested to ensure that available spark energy is incapable of causing ignition at each point where an interruption or interconnection can occur. Note to entry: For Group I and II, the contact to explosive atmosphere can be excluded by coating, encapsulation, moulding or equivalent means. For Group III, the contact to explosive atmosphere can be excluded by the means acceptable for Group I, Group II and additionally by protection measures in accordance with clause 6.1.3

Not accepted. Coating, encapsulation and moulding etc only obviate spark ignition assessment if Table 5/6/7 distances are met. Hence “that come in contact with the explosive atmosphere” could be misinterpreted. Spark ignition risk can be transferred down wires whereas thermal ignition risk cannot so alignment is not appropriate.

DE-032

792 5.4.1 1st para Ed This clause is only applicable for intrinsically safe apparatus.

All surfaces that come into contact with explosive atmospheres shall be assessed and/or tested to ensure that, after the application of faults as required by 5.2, the intrinsically safe apparatus complies

Accepted in principle, add “of intrinsically safe apparatus” after surfaces.

GB-044

793 5.4.1 ed Thermal ignition compliance is required in normal operation as well as under fault conditions.

Replace “after the application of faults as required by 5.2” with “under the conditions specified in 5.2”

Accepted

AU-12

795 5.4.1 1 Te The IEC 60079-0 requires a 10% increase in voltage for temperature rise measurements. However, this is not applied to intrinsic safety parameters Ui and Ii. Clause 5.4.5 Line item 889 clearly refers to this for Group III. A similar sentence is required for Group I and II also.

Add at the end of first paragraph, add “In contrast to IEC 60079-0, the measurement shall be made using the specified values of Ui and Ii for the intrinsically safe apparatus without a 10 % safety factor.” Having done the above, the above sentence then applies for all Groups, and can be removed from the Clause 5.4.5.

Accepted in principle, added before sentence referring to 9.2.

FR-03

795 5.4.1 1st te Cl 5.4.4 also adds requirements for thermal ignition compliance

Modify this sentence: “with the maximum surface temperature requirements of IEC 60079-0 as modified by 5.4.2, 5.4.3, 5.4.4, and 5.4.5”

Accepted

DE- 796 5.4.1 Note 1 Ed This Note is not needed if the clause is applied to Delete Note 1 Not accepted, note is needed to clarify that this is

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033 IS apparatus only. not usually applicable for associated apparatus. See also US-010.

US-010

796 5.4.1 Note 1 te This note conflicts with the use of 5.4 for the rating of infallible conductors in associated apparatus. Revise the note to address this.

Note 1 Associated apparatus protected by another Method of Protection listed in IEC 60079-0 or located outside the hazardous area are not subject to the provisions of this clause other than when used to asses an infallible connection in accordance with 6.4.

Accepted in principle – slight rewording

GB-045

800 5.4.1 NOTE 2 ed This should apply to “ic” as well, i.e. not just fault conditions.

Replace “fault conditions defined” with “conditions specified”

Accepted

DE-034

805 5.4.2 1st para Ed The title of clause 5.3.3 of IEC 60079-0 is: Small component temperature for Group I or Group II electrical equipment

Remove “requirements” at the beginning of line 805 and write as follows: Requirements for temperatures of small components used in Group I or Group II equipment are provided in small component temperature for Group I or Group II electrical equipment of IEC 60079-0…

Accepted in principle, changed to Requirements for small component temperature for Group I or Group II electrical equipment from IEC 60079-0 apply

DE-035

817 5.4.3 te What is the origin of coefficient used / where does 0.004284 K^-1 came from? usual for copper (acc. To TH-Darmstadt Script “passive components”): a_0 °C (273.15 K) = 0.00427 K^-1 a_20 °C (293.15K) = 0.003862 K^-1 a_25 °C (398.15 K) = 0.00382 K^-1 for temperatures we using a_100 °C: tbd

To be consistent with 9.2 the coefficient for 0°C should be used a (0°C) = 0.00427 1/K) (1/a = 234,52 K)

Accepted

GB-046

835 5.4.3 Table 2 ed NOTE 5 uses “can” to provide permission. All of the notes to the table are an indispensable part of the standard and therefore should not be notes.

Change NOTE 5 “can be” to “may be” Make normative text rather than notes.

Accepted

GB-047

835 5.4.3 Table 2 te Can a note be added for ambient temperatures above 40°C i.e. NOTE 6 that allows for values of wire diameter or CSA with a reduced value i.e. values should be reduced by ?%, ?%, ?% and ?% for ambient temperatures of 50, 60, 70 and 80°C respectively. This can be the same as the reduction factors specified in Table 3 for PCB tracks.

Add reduction factors to the values in Table 2 to compensate from higher than 40°C ambient temperatures.

Not accepted. MT supports this approach; however, no factors have been provided. The MT considers the factors from Table 3 not applicable to heating of wires. GB is invited to submit factors for consideration. MT requests that GB

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ensure that this matches with the often used assumption that, for instance the T6 current represents thermal rise of 40K thus can be used for T4 at up to 90°C ambient.

BR-01

- 5.4.4 - te It is common on intrinsically safe apparatus the application of encapsulation for exclusion of explosive atmospheres of small component, tracks and connections for thermal ignition or sparking ignition protection purposes, as consequence, tracks in the surface of the boards are also encapsulated and then have the temperature class rated as such. However, there are situations where the sides of the board are not encapsulated, therefore the inner layers can be considered as “exposed” and therefore should have the temperature classified according to this clause.

Include a paragraph to explain the assessment or testing requirements for inner layers of boards with sides exposed and surfaces encapsulated per clause 6.5. Example: “Boards with surfaces encapsulated per clause 6.6, but with exposed sides require temperature classification according to this clause”. NOTE: This text considers that the insulative materials applied on boards does not exclude the explosive atmosphere from inner layers. Otherwise, a specific reference should be provided in standard to allow the alignment when assessing boards under these conditions.

Accepted in principle. Revise 5.4.4 paragraph 1 to make it clear that this section applies only to tracks of printed circuit boards exposed to the explosive atmosphere.

CH-15

840 5.4.4 te Clause 5.4 handles thermal ignition compliance. Though we would like to propose the temperature classification of tracks to be suitable for judging the current carrying capacity of tracks, we should avoid in clause 5.4.4 information which is not directly related to thermal ignition compliance. In our understanding it would be preferable to find all requirements on tracks at the same location. In the context of the requirements on the current carrying capacity on tracks, the reference to clause 5.4.4 might exclude the exception for track length less than 10 mm used for thermal ignition compliance. We would suggest to use clause 6.4.2.4, printed circuit boards.

Reinstall the following sentence as it was in the 6th edition: Tracks with lengths of 10 mm or less shall be disregarded for temperature classification purposes. but must meet the requirements of this section to be considered a countable open circuit fault.

Accepted. 6.4.1 addresses this situation as it states “Failure to open-circuit of any conductor, connector or printed circuit board track, including its connections, which does not comply with 6.4.2 shall be considered a countable fault in accordance with 5.2, if rated for the maximum current or thermally rated in accordance with 5.4.” Also deleted the last paragraph of 6.4.2.1 as the requirements were redundant with those found in 6.4.1. To distinguish between ‘infallible’ and standard fault analysis, the

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countable fault rows of Table 8 were deleted.

DE-036

840 ff

5.4.4 Te “Tracks with lengths of …. must meet the requirements of this section to be considered a countable fault.” What does thermal assessment have to do with failure of tracks? Should be better specified.

Replace with “Tracks with lengths of 10 mm or less shall be disregarded for temperature classification purposes but shall be in accordance with table 3 if intrinsic safety depends on the connection.” Additionally replace in chapter 6.4.2.4 term “5.4.4” with “table 3 of 5.4.4”

Accept in principle in part (see CH-15). Revise to remove “but must meet the requirements of this section to be considered a countable open circuit fault.” The PCB TG does not accept that all tracks upon which intrinsic safety depends must meet Table 3. They would also be acceptable if they are assessed using other available data or direct measurement.

US-011

842 5.4.4 te It is not clear what ‘requirements of this section’ means for tracks lengths < 10mm. Do the temperature classification requirements need to be met, or only maximum permissible current?

Replace the text with ‘Tracks with lengths of 10 mm or less shall may be disregarded for temperature classification purposes but must meet the temperature classification and maximum permissible current requirements of this section to be considered a countable open circuit fault (see 6.4.1).’

Not accepted. This issue is addressed by changes made in response to CH-15. Further, it is clear in 6.4.1 that tracks may be rated either for maximum current or thermally rated in accordance with 5.4.

AU-13

846 5.4.4 1 Ed The example formatting looks a little odd here. Should this just be note, it’s not really an example of how to apply the standard, it is a note of where available data can be found?

Change to note: Note 1 IPC-2221 and IPC-2152 are examples of available data.

Accepted

US-012

846 5.4.4 EXAMPLE ed The example should be a note. Change “EXAMPLE” to “NOTE” Accepted in principle, see AU-13

GB-048

849 5.4.4 Second Par. ed Should the text “and is acceptable for Group I at a maximum ambient temperature of 40 °C.” read “and is acceptable for Group I at a maximum ambient temperature of 40 °C where dust is not excluded by enclosure.”?

Change text to read: - “and is acceptable for Group I at a maximum ambient temperature of 40 °C where dust is not excluded by enclosure.”?

Not accepted. The current text agrees with the relevant section (5.3.3) of 60079-0.

DE-037

850 5.4.4 Te “where dust is excluded” it is assumed this is in regards to dust on the traces, not that the device is not rated Da, Db, or Dc. It might be good to

Change sentence to: “Where the circuitry is housed in an IP5x enclosure to exclude dust in a Group I application

Not accepted. The current text agrees with the relevant section

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include a reference to IP54 here. and the maximum power dissipation in the track does not exceed 3.3W,….”

(5.3.3) of 60079-0.

DE-038

855 5.4.4 Na ed The chapter might be misread in a way that this calculations is only applicable for runners with a surface area of ≥20mm2 This cannot be the intend as tracks with a length of ≤10mm are excluded from this assessment anyway (line 840) We propose to add an example for the calculation of the power dissipation below line 855 or a note to make this clear

Example: A copper runner with a cross-section of 0.00825 mm2 (copper thickness of 33um, width of 0.25mm) and a length of 100mm carrying a maximum current of 2A would have a power dissipation of 0.863W and comply to the limit of 1.3W for Group I and II, T4 for 40°C maximum ambient temperature. Alternatively add a Note Note: Only the power dissipation is relevant. The surface area limitation of ≥ 20mm2 referenced above is not applicable in this context

Accepted in principle. Revise the text to remove the awkward inclusion of the 60079-0 table title. “Refer to IEC 60079-0 where a derating is required for ambient temperatures greater than 40 C.”

DE-039

862 to 863

5.4.4 3rd Para Te The last paragraph allows interpolation on every item. Suggestion is only to allow interpolation on track width together with the current, but not to the factors. The 2nd sentence unnecessarily repeats what is stated in Table 3.

New proposed wording of 3rd para with 2nd sentence deleted “Where the tracks are made of copper, the temperature classification may be determined using Table 3. The values found in the table shall be adjusted depending on the actual board thickness, number of track layers, copper plating thickness, ambient temperature, and whether the track connects to terminals or passes under components dissipating more than 0,25 W. When applying Table 3 and the associated adjustment factors, linear interpolation between current and track width is allowed. However, interpolation with the factors is not premitted. The maximum permissible current is calculated as shown below:” Caused by this, the factor tables need adjustments to show ranges, not absolute numbers e.g. for board thickness:

Board Thickness (mm) Factor

> 1.6 1

> 0.5 to < 1.6 0.83

Accepted in part. Revise paragraph to remove the second sentence which repeats text found in Table 3. This section was revised to remove the word ‘linear’ as the reference IPC standards allow interpolation but in some cases, the relationships are not linear. A restriction on extrapolation was added to make it clear that this is not allowed.

GB-049

865 5.4.4 ed ‘Table 3 values’, could be either track thickness of current values. For clarity identify this as the maximum permissible current for temperature classification

Modify text: Maximum Permissible Current = Table 3 Value IFTC x FBT x FLY x FCT x FUC x FTR x FAT IFTC = maximum permissible current for temperature classification

Accepted in principle. Revise paragraph to replace “Table 3 Value” with “I = Maximum permissible current for temperature classification

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found in Table 3” and revised other text as appropriate.

GB-050

865 - 886

5.4.4 ed As much as the pronunciation of these symbols brings some welcome light relief, a different letter to F might be more appropriate.

Replace F with λ in the symbols. Accepted

US-013

869 5.4.4 3 ed Rename the circuit board factors to enhance readability.

Change: FBT > FB, FLY > FL, FCT > FT, FUC > FC, FTR > FP, FAT > FA

Accepted

DE-040

870 5.4.4 ed what does # mean? replace # with "Number" Accepted

DE-041

873 5.4.4 ed What is the intention of the FTR factor? Change “terminals” to “terminations” Also in NOTES 2. In Table 3.

Not Accepted. The ‘terminations’ factor has been removed. See CH-16 for further information.

US-014

881 5.4.4 Example ed Revise factors per previous comment Revise factors per previous comment Accepted (per US-013)

GB-051

885 5.4.4 Table 3 ed The NOTE is an indispensable parts of the standard.

Delete the word “NOTE” to make the text normative.

Accepted

GB-052

885 5.4.4 Table 3 ed NOTES should be footnotes Delete the word “NOTE”, make the bullet point numbers superscript (See DIR2 29.6 example 1).

Accepted

CH-16

885 5.4.4 Table 3, Note 2

te The requirement for factor (FTR) seems to be in contradiction to the exception for track length of equal to or less than 10 mm.

We would appreciate to look into this requirement more deeply until the next meeting.

Accepted in principle. It is difficult to understand how a 1mm length of track that is close to a component termination is an issue if tracks less than 10 mm are to be ignored. It is not clear exactly how to fix this since removing the 1mm reference would imply that the entire track would be affected if a connection was made to a component terminal (which most tracks do). The ‘terminations’ factor was removed as it is the feeling of the TG that the power dissipating

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component would be much hotter than the low resistance trace connected to the component terminations. The under component factor was retained since these tracks may not connect to the component that it is running under. Therefore, the above argument does not apply.

DE-042

885 5.4.4 Table 3 Te Distinguish Factors applicable for outer layers and inner layers as in IPC 2221. The 0.5 factor should only apply for internal traces, while using 0.67 for external. Currently all would be 0.5 which seems too restrictive. IPC 2152 does not distinguish between inner and outer layers, but is more conservative for outer layers compared to IPC 2221. IPC 2221 distinguishes between inner and outer layers, independent of dual layer or multilayer.

To keep differences between inner and outer layers, but also following IPC 2221 the following table is proposed.

Number of Layers Factor

1 1

2 0.67

>2 0,67 for outer layers

0,5 for inner layers

Not accepted. Thermal rating of tracks on inner layers should not be required since they are not exposed to the explosive atmosphere. The section has been revised to remove any requirements for current capacity needed for allowing tracks to form part of infallible or countable connections. Neither IPC standards nor Table 3 provide guidance necessary to assess the thermal ignition risk of inner layer tracks. This would have to be done through direct measurement as required in 6.5.2.2.

DE-043

885 5.4.4 Table 3 Te Add a 100ºC step to the ambient temperature factor table. According to IPC 2152 figure 5.2 the current for 30°C warming is about 1,85 times smaller than the current for 100°C warming. The maximum temperature for T4 is 130°C. At an ambient of 40°C there are 90 K left for warming of the track. At 100°C ambient, this reduces to 30 K. Pold / Pnew = 90K / 30K

Add a 100ºC step with the factor 0.57 restricted to T4 to the ambient temperature factor table.

Accepted in principle. Revised as indicated. Added restrictions for 100C for T5 and T6 as these do not allow any temp rise at a 100C ambient. Revised other parameters based on review of existing data such as IPC-2221.

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with: P = I² x R Inew = Iold / Root(90/30) Inew = Iold / 1.73 = 0.57 for 100°C (only for T4)

DE-044

885 5.4.4 Table 3 Te The temperature around tracks is the service temperature, not the ambient temperature:

Propose rename this factor to service temp. instead of ambient temp.

Not accepted. This would be a major departure from the previous versions of the standard. In this case, the service temperature is taken into account through application of the factors.

DE-045

885 5.4.4 Table 3 Ed Only absolute values are given for board thickness, copper thickness and ambient temperature.

Change to: minimum copper thickness Maximum ambient temperature

Not Accepted. Assuming interpolation is allowed, these values may be left as discrete points.

DE-046

885 5.4.4 Table 3 ed what does # mean? replace # with "Number" Accepted

DE-047

885 5.4.4 Table 3 te The requirement listed in Note1 and 2. In Table 3 relating to tracks passing under and at terminals of components that dissipate 250mW results in a width increase of the runner by that factor 2 for 1mm along the track. This does not seem to tally with the exclusion of tracks of less than 10mm (line 844). In addition the contributions of a 1mm or 10mm long piece of track to the power dissipation in the presence of a component that dissipates 250mW or more is negligible. Example: A resistor of 1 Ohm is connected to a source that supplies a current of 0.5 A max (worst case, failures considered). Board thickness 1mm, multilayer board (>2 layers), Cu thickness 18um, 60°C results in factor of 0.23. Per Table 3, a track width of 0.3mm would be required. The power dissipation of a 1mm section of that track is ~0.82mW ~ 0.33% of 250mW. A section of 10mm of the same track would dissipate ~ 8.2mW which is ~3.3% of 250mW. This should be negligible.

Delete Note1 and 2 and the factors for passing “Under Component” FUC and “At Terminals” of components FTR.

Accept in principle. It is difficult to understand how a 1mm length of track that is close to a component termination is an issue if tracks less than 10 mm are to be ignored. It is not clear exactly how to fix this since removing the 1mm reference would imply that the entire track would be affected if a connection was made to a component terminal (which most tracks do). The ‘terminations’ factor was removed as it is the feeling of the TG that the power dissipating component would be much hotter than the low resistance trace connected to the component terminations. The under component factor was

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retained since these tracks may not connect to the component that it is running under. Therefore, the above argument does not apply.

US-015

885 5.4.4 Table 3 ed Revise factors per previous comment Revise factors per previous comment Accepted (per US-013)

GB-053

887 5.4.5 Table 4 te The values listed in Table 4 are linear. This makes it possible to calculate power levels for ambient temperatures other than those listed in Table 4.

Add a statement or note to allow for interpolation between listed values i.e. 100 mW / 30°C or 3 1/3 mW / °C. Alternatively, expand table to give intermediate values; e.g. 700mW at 55°C and 600mW at 85°C.

Accepted in principle, permission added in table 4

GB-054

892 5.4.5 1st para ed Normal operation is also applicable, not just fault conditions. “regarding” is not consistent terminology

Replace “regarding the fault conditions as” with “under the conditions”

Accepted

CH-17

894 5.4.5 te In order to avoid uncertainty, enclosure requirements for Group III equipment should be collected in clause 6.1.3. Use text as laid down in 31G/249E/INF, modified and added by a note.

Example Intrinsically safe apparatus protected by enclosure of at least IP5X, the surface temperature of the enclosure shall be measured. Note to entry: For enclosure requirements see 6.1.3.

Accepted in principle. Delete: Intrinsically safe apparatus for Group III which relies on an enclosure of at least IP5X shall additionally comply with the metallic and non-metallic enclosure requirements of IEC 60079-0.

GB-055

896 5.4.5 2nd para ed Reference to a current might be interpreted as implying that this applies to spark ignition compliance as well as thermal,

Add “for the purposes of thermal ignition compliance” after “total immersion”

Accepted in principle, change to: Intrinsically safe apparatus shall be considered suitable for total immersion, or an uncontrolled dust layer thickness, if the power dissipation in any component under the conditions specified in 5.4.1. is in accordance with Table 4, and the continuous short-circuit current is less than 250 mA for the purpose of thermal

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ignition compliance after total immersion. The intrinsically safe apparatus shall be marked T135 °C.

US-016

896 5.4.5 Par 2 ed Place a comma after the word alternatively. Alternatively, intrinsically safe apparatus Accepted

GB-056

897 5.4.5 2nd para ed With semiconductor limiting, matched power can be less than the maximum power. Clarify that this in under fault conditions.

replace “matched power” with “maximum power under the conditions of 5.2“

Accepted in principle. Same text as in previous paragraph is used. For the text see comment GB055.

SE-04

902-937 5.5 Ed Clarify that a simple apparatus, alternatively (on the manufacturer’s choice) can be considered as an intrinsically safe apparatus and assessed as such.

Add the following note: “NOTE 3: The standard does not exclude a simple apparatus to be considered as an intrinsically safe apparatus and assessed as such (all requirements for intrinsically safe apparatus apply in such a case).”

Not accepted. “shall be considered” in opening sentence changed to “may be considered”. This is not excluded by the standard as written.

DE-048

911 5.5 ed “comply with to” typing error. Extra word. Delete “to” Accepted

GB-057

911 5.5 ed “comply with to” typing error. Extra word. Delete: “to” Accepted

GB-058

921 1759 2006 2110 2155 3037 3486

5.5 6.8 7.6.4 7.7.4 7.8.1 9.12.3.2 B.1.2

ed The term ‘shall be capable’ is frequently used within the standard. Sometimes this is followed up by a statement such as ‘of complying with the test described in 9.3’ but there are occurrences where there is no test defined.

Review all occurrences of ‘shall be capable of’ and where a specific test is required change this to ‘shall pass the test specified in XX’ or similar. Where no specific test is mentioned either; - change this so that this capability is based on a rating and state this, or - add a reference to the specific test that the component needs to pass.

Noted. B.1.2 remains without a specified pressure test.

DE-049

928 5.5 Ed “When used in an intrinsically safe circuit within their normal rating…” seems grammatically wrong: “circuit” is singular, “their” is plural

Change to: “When used in intrinsically circuits….”

Not accepted. “their” refers to the switches, plugs, sockets, etc which are plural

DE-050

935 5.5 ed Better phrase Delete this last sentence in note 1 and replace with comment that such sensors are not in scope of 79-11. See clause 1 line 434

Accepted in part Words reflecting the scope are not added, as this note refers to more than just catalytic sensors.

GB- 939 6 Note ed This note directly affects the scope of the clause Change from NOTE to new subclause 6.1 Scope Accepted in principle, call

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059 and hence the standard would not be the same without it. It should not therefore be a note.

Change “sections” to “subclauses” the subclause “general”.

DE-051

940 6 ed “Contribute” is more in the meaning of “adding”. Meant is more “covered” – as part as

“…..only those features…apparatus on which this type of protection depends.”

Accepted

AU-14

946 6.1.1 1 Ed In the present sentence, the example refers to the necessity of an enclosure if there are infallible creepage distances. Since distances less than infallible also require enclosure (for example, if > 1/3) vary the text as shown. Also change to appropriate example formatting.

Revise to: Where intrinsic safety can be impaired by ingress of moisture or dust or by access to conductive parts an enclosure is necessary. Example Where circuits contain separations necessary for intrinsic safety,

Accepted in principle, example modified.

DE-052

951 6.1.1 Ed “The enclosure need not…” seems grammatically wrong: “enclosure” is singular, “need” is plural

Ask native-speakers… Not accepted: “need not” is a modal verb to the main verb “be”.

SE-05

962-964 6.1.2.2 1st para Ed/Te IP 20 or greater is required according to the standard for Group I apparatus complying with Table 5. However, IP 20 as a minimum seems not to be enough for apparatus with safety-related distances according to Table 5, to be used in Group I environment. Shouldn’t the minimum requirement be IP 54?

Amend the para to read: “…meeting the requirements of IP 20 for Group II and IP 54 for Group I in accordance with IEC 60529 or greater according to the intended use and environmental conditions.”

Not accepted, higher IP ratings might be necessary (see 6.1.1) but this would mandate the use of IP 54 enclosures for Group I and would be a major technical change.

US-017

967 6.1.2.3 te Because inner layers of PCBs are protected from pollution, is it possible to allow the reduced spacing of Table 6 for the inner layer (while the outer layers may need to comply with Table 5)? Another scenario would need to be added to 6.1.2.3 to allow this. Also, the titles/verbiage of 6.1.2.2 and 6.1.2.3 would need to be modified as ‘apparatus’ implies that the entirety of the I.S. equipment needs to either comply with Table 5, or Table 6 (or Table 7 for ‘ic’), but not a combination of them.

Consider adding a scenario to 6.1.2.3 for inner layers of PCBs.

Accepted in principle. Revise 6.1.2.3 b) to reflect that separations located on inner layers of a multi-layer PCB are also considered adequately protected. Adjusted the text of the affected paragraphs to reflect that in some cases, only parts of the apparatus may rely on specific separation requirements.

GB-060

969 6.1.2.3 ed Missing space add space between “ib” and “or” Accepted

US-018

969 6.1.2.3 ed Space is missing after “ib” “ib” or Accepted

DE-053

969 6.1.2.3 Ed Blank is missing between “ib” and or Include blank Accepted

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AU-15

969 6.1.2.3 1 ed Missing space between “ib”or Modify the text: “ib”_or

Accepted

CH-18

971 6.1.2.3 a) te With the new wording, due to references to 6.1.2.3 a) from other parts of the standard, the naming of the requirement for pollution degree 2 under sub-clause a) PD2 requirement would leave the context the former annex F and would be related to equipment complying with Table 5 as well. Therefor we see the need to limit the requirements stated in a) to the IP54 rating according to requirements laid down in IEC 60079-0. The introduction and the sub-clauses a), b) and c) were modified accordingly. For b) beside the coating type 1 or type 2 protection according to IEC 60664-3, distance through casting compound, moulding and solid insulation were added, as these protection measures are allowed to former Annex F.

6.1.2.3 Apparatus complying with Table 6 or Table 7 Apparatus meeting the separation requirements of Table 6 for Levels of Protection “ia” and “ib” or Table 7 for Levels of Protection “ic” shall be suitable for the intended use and environmental conditions providing a pollution degree 2 or better. One of the following protection systems shall be provided: a) the enclosure shall be suitable for the

environmental conditions in accordance with industrial standards and the equipment shall be tested for ingress protection IP54 in accordance with IEC 60529 fulfilling the requirements of the clauses of IEC 60079-0 identified in Table1. NOTE It is not a requirement of this standard that the conformity with industrial standards needs to be verified

b) the enclosure protecting the printed circuit board assemblies and/or separation components shall provide a degree of ingress protection not less than IP20 according to IEC 60529 and separations shall be provided with coating type 1 or type 2 protection according to IEC 60664-3, distance through casting compound and/or distance through solid insulation. The enclosure does not need to be subjected to the tests for enclosures in IEC 60079-0; however for portable apparatus, the drop test of IEC 60079-0 still applies.

c) the enclosure for the equipment shall provide a degree of ingress protection not less than IP20 according to EN 60529 and the installation shall be restricted to environments providing pollution degree 2 or better. The enclosure does not need to be subjected to the tests for enclosures in IEC 60079-0. The certificate shall specify the restricted installation requirements as Specific Conditions of Use and the certificate number shall include

Accepted in part See re-write of 6.1.2 Conflict with 6.1.3 a) addressed; PD2 only in c), coating or IP54 considered to be sufficient. Addition to a) rejected “in accordance with the industrial standards” which according to the Note shall not be verified.

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the "X" suffix in accordance with the marking requirements of IEC 60079-0.

DE-054

971 to 974

6.1.2.3 Clause a) Ed “an enclosure suitable for the intended installation and environmental conditions providing a PD 2” sounds not easy to understand. Additionally reference to IEC 60529 is missing

Change to “an enclosure suitable for the intended installation and the environmental conditions. The enclosure shall provide a PD2 or better for the separations under concern, however with a minimum of IP54 according to IEC 60529.”

Not accepted see CH-18 PD2 and IP54 is a clash

US-019

971 6.1.2.3 a) ed Reword for clarity a) an enclosure suitable for the intended installation and environmental conditions providing a pollution degree 2 or better for the separations under concern relied upon for intrinsic safety and with a minimum of meeting the requirements of at least IP54. For such enclosures, the clauses of IEC 60079-0 identified in Table 1 additionally apply.

Accepted in principle. Text moved into leading para.

FR-04

972 6.1.2.3 a) te Introduction of the notion of “pollution degree” without defining this word or context

Add after “providing pollution degree 2” the context “according to IEC 60064-1".

Accept in principle. Added “according to IEC 60664-1” in c)

IT-03 973 6.1.2.3 a) ed “… of IP 54” Add “… of IP54 according to IEC 60529.” Accepted. See re-write of 6.1.2.

DE-055

973 6.1.2.3 a) Ed Blank between IP54 and dot Delete Accepted

DE-056

975 to 980

6.1.2.3 b) Ed In the actual standard also separations provided with solid insulation and encapsulation are listed as measures that relax the requirements for enclosures.

Change this bullet point as follows: b) an enclosure suitable for the intended installation and environmental conditions protecting the printed circuit board assemblies or separation components, with a minimum of IP20 according to IEC 60529 provided that separations are provided with coating type 1 or type 2 protection according to IEC 60664-3, or with casting compound or with solid insulation. The enclosure does not need to be subjected to the tests for enclosures in IEC 60079-0; however, for portable apparatus, the drop test of IEC 60079-0 still applies.

Accepted in principle. See re-write of 6.2.1

US-020

975 6.1.2.3 b) ed Reword for clarity b) an enclosure suitable for the intended installation and environmental conditions protecting the printed circuit board assemblies or separation components separations relied on for intrinsic safety, meeting the requirements of at least with a minimum of IP20 according to IEC

Accepted in principle. See re-write of 6.2.1 “protection” after “type 1 or type 2” shall remain to match with 60664-3 which uses “protection” not

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60529, provided that separations are provided protected with coating type 1 or type 2 protection according to IEC 60664-3. The enclosure does not 979 need to be subjected to the tests for enclosures in IEC 60079-0; however for portable apparatus, the drop test of IEC 60079-0 still applies.

“coating”

BR-02

978 6.1.2.3 b) 1st te In the Edition 6, separations obtained through casting compound and solid insulation are allowed to avoid the need of applying the mechanical strength testing from IEC 60079-0. These technics of additional insulation and protection against moisture and dust are known to be equal or better than coating.

On this line add casting compound and solid insulation as it was previously provided: “…provided that separations are obtained by using coating type 1 or type 2 protection according to IEC 60664-3 or casting compound or through solid insulation.”

Accepted in principle. See US-020

DE-057

981 to 985

6.1.2.3 c) Ed For consistency use the same wording to start as in a) and b)

c) an enclosure suitable for the intended installation and environmental conditions protecting the printed circuit board assemblies or separation components, with a minimum of IP20 according to IEC 60529 and restriction to installation in environments providing pollution degree 2 or better. The certificate…

Accepted in principle. See re-write of 6.2.1 Instead of “better” use “1” following GB-061

IT-04 981 6.1.2.3 c) ed “… according to EN 60529….” Change to “… according to IEC 60529….” Accepted

US-021

981 6.1.2.3 c) ed Reword for clarity c) an enclosure meeting the requirements of at least IP20 according to EN 60529 and restriction restricted to installation in environments providing pollution degree 2 or less. The certificate shall specify the restricted installation requirements as Specific Conditions of Use and the certificate number shall include the "X" suffix in accordance with the marking requirements of IEC 60079-0.

Accepted in principle. See re-write of 6.2.1

GB-061

982 6.1.2.3 c) ed an enclosure meeting the requirements of IP20 according to EN 60529 and restriction to installation in environments providing pollution degree 2 or less. In this sentence, what is less? Pollution degree 1 or 3. Since Pollution degree 1 is better can we just list that as well?

an enclosure meeting the requirements of IP20 according to EN 60529 and restriction to installation in environments providing pollution degree 2 or 1 less.

Accepted

FR-05

982 6.1.2.3 c) ed Introduction of the notion of “pollution degree” without defining this word or context. Use the wording “a pollution degree 2 or better”

Modify this sentence: “providing pollution degree 2 or better according to IEC 60064-1".“

Not accepted. GB-061 accepted instead

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(e.g. Table 1)

Type of comment


in a), and “a pollution degree 2 or less” in c): it could be aligned for consistency

CH-19

986 6.1.3 For facility of assessment and inspection it seems to be recommended to use for clauses and sub-clauses the same structure for Group I/II and Group III. For clause 6.1.3.2 the discussion on the requirements is not yet terminated. A separation of the Groups IIIC and IIIB/IIIA might result in testing IIIC equipment for compliance with the requirements of the clauses of IEC 60079-0 identified in Table1, whereas Group IIIB/IIIA equipment might be handled in the same way as Group I equipment. This might result in the separation of the different requirements in 6.1.3.2 by subclauses a) and b) By harmonization of 6.1.2 and 6.1.3 the last sentence becomes redundant.

6.1.3 Enclosures for Group III apparatus 6.1.3.1 General Intrinsically safe and associated apparatus which rely on the separation requirements in Table 5 or Table 6 or Table 7 shall be provided with an enclosure meeting the requirements of 6.1.3.2 or 6.1.3.3 as applicable. 6.1.3.2 Apparatus complying with Table 5 Apparatus meeting the separation requirements of Table 5 shall be provided with an enclosure meeting the requirements of IP5x in accordance with IEC 60529 or greater according to the intended use and environmental conditions. The enclosure does not need to be subjected to the tests for enclosures in IEC 60079-0; however for portable apparatus, the drop test of IEC 60079-0 still applies. 6.1.3.3 Apparatus complying with Table 6 or Table 7 Apparatus meeting the separation requirements of Table 6 for Levels of Protection “ia” and “ib”or Table 7 for Levels of Protection “ic” shall be suitable for the intended use and environmental conditions. One of the following protection systems shall be provided: a) the enclosure shall be suitable for the

environmental conditions in accordance with industrial standards and the equipment shall be tested for ingress protection IP54 in accordance with IEC 60529 fulfilling the requirements of the clauses of IEC 60079-0 identified in Table1. NOTE It is not a requirement of this standard that the conformity with industrial standards needs to be verified

b) the enclosure protecting the printed circuit board assemblies and/or separation

Not accepted Requirements for group IIIA and IIIB are aligned with Group I. The text has been changed and some parts of this comment may still be relevant. Further comments should be submitted if required.

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(e.g. Table 1)

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components shall provide a degree of ingress protection not less than IP2x according to IEC 60529 and separations shall be provided with coating type 1 or type 2 protection according to IEC 60664-3, distance through casting compound, through moulding and/or distance through solid insulation. The enclosure does not need to be subjected to the tests for enclosures in IEC 60079-0; however for portable apparatus, the drop test of IEC 60079-0 still applies.

c) the enclosure for the equipment shall provide a degree of ingress protection not less than IP2x according to EN 60529 and the installation shall be restricted to environments providing pollution degree 2 or better. The enclosure does not need to be subjected to the tests for enclosures in IEC 60079-0. The certificate shall specify the restricted installation requirements as Specific Conditions of Use and the certificate number shall include the "X" suffix in accordance with the marking requirements of IEC 60079-0.

Enclosures for Group III associated apparatus shall meet the requirements of 6.1.2.

DE-058

986 6.1.3 Te Clause discusses impairment of safety by ingress of dust. Would the requirements be different for conductive (IIIC) vs non-conductive (IIIB) dust group? Restructure 6.1.3 to differ in the requirements for IIIC and IIIA/IIIB and for better readability

6.1.3 Enclosures for Group III 6.1.3.1 Group III intrinsically safe apparatus For intrinsically safe apparatus an enclosure is necessary per one of the following: a) For Group IIIB or IIIA devices where separation is accomplished by meeting the requirements for clearances or creepage distances of Table 5, an enclosure of at least IP5X according to IEC 60529. The enclosure does not need to be subjected to the tests for enclosures in IEC 60079-0; however for portable apparatus, the drop test of IEC 60079-0 still applies. b) For Group IIIB or IIIA devices where separation is accomplished by meeting the requirements for clearances or creepage distances Table 6 or

Accepted in principle. Requirements for group IIIA and IIIB are aligned with Group I in 6.1.2.

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(e.g. Table 1)

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Table 7, an enclosure as required in 6.1.2.3 a) shall apply. c) For Group IIIC devices where separation is accomplished meeting the requirements for clearance or creepage distances Table 5, Table 6, or Table 7, an enclosure as required in 6.1.2.3 a) shall apply. d) For Group III devices where separation is accomplished by meeting the requirements for distances under coating, casting compound or separation distances through solid insulation of Table 5, Table 6 or Table 7, the enclosure shall provide a degree of protection of at least IP2X, according to IEC 60529. The enclosure does not need to be subjected to the tests for enclosures in IEC 60079-0; however for portable apparatus, the drop test of IEC 60079-0 still applies. 6.1.3.2 Group III associated apparatus Enclosures for Group III associated apparatus shall meet the requirements of 6.1.2.

GB-062

987 6.1.3 te The first sentence seems to be attempting to redefine what Group III means. The example is not helpful since it only applies to a). Requiring that one or the other is met does not make logical sense if (for example) both creepage and distance under coating are used.

Delete first sentence and remove a) and b) bullet points (leaving text). Replace text from a) with:

Where separation for Group III intrinsically safe apparatus is accomplished by meeting the requirements for clearance and creepage distances, the requirements of 6.1.2.3 a) shall apply and the enclosure shall meet the following according to IEC 60529: - where Table 5 is used, an enclosure of at least IP5X; - where Table 6 or Table 7 are used, an enclosure of at least IP54.

Start text from b) with “Otherwise,”.

Not accepted. The MT considers the example to apply to a) and b), because it describes the situation before requirements of 6.1.3 are applied. As the text proposed for the next CD has changed we would like the national committee to judge if their proposal is still necessary and to apply it on the next CD if necessary.

AU-16

988 6.1.3 1 Ed The first paragraph restates what is already in the general clause, including the example.

Revise to : Where an enclosure is required for Group III equipment, it shall comply with one of the following:

Not accepted. The general clause refers to apparatus whereas 6.1.3 explicitly refers to intrinsically safe apparatus. The general clause refers to pollution (moisture or dust) whereas 6.1.3

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explicitly refers to dust. Differentiation should be kept for clarity.

AU-17

990 6.1.3 Te The required IP ratings should align with 60079-31 for the different dust subgroups.

Change to: a) Where separation is accomplished by meeting the requirements for clearance or creepage distances of Tables 5, 6, or 7, an enclosure of at least the IP ratings given in Table X and the requirements of 6.1.2.3 a) shall apply. Additionally where Tables 6 or 7 are used, at least IP54 is required according to IEC 60529. Copy Table 1 from 60079-31 and change the levels of protection to reflect intrinsic safety.

Not accepted Based on the discussion in the maintenance team requirements for Group IIIA and IIIB are aligned with those for Group I in 6.1.2.

US-022

990 6.1.3 a) ed Reword for clarity a) Where separation is accomplished by meeting the requirements for clearance or creepage distances of Table 5 an enclosure of at least IP5X, or when Table 6 or Table 7 are applied, an enclosure of at least IP54 according to IEC 60529. For such enclosures the requirements of 6.1.2.3 a) shall additionally apply.

Accepted in principle. Wording for Table 6 and 7 is aligned with wording for Table 5. Reference for intended use and climate conditions is added in the general part.

GB-063

992- 993

6.1.3 a) ed Confusing cross-reference between Group II and Group III enclosure requirements. Reference is made to requirements of 6.1.2.3 a) that is IP54 not IP5X.

List requirements in 6.1.3 instead of cross reference to 6.1.2.3 a).

Accepted

FR-06

992 6.1.3 a) te This bullet asks for: EITHER IP5x when table 5 applied, OR IP54 when table 6 or table 7 applied. AND Applying 6.1.2.3 a) in all cases But in 6.1.2.3 a), IP54 is mandatory. Strictly applying this clause, IP54 seems to be always mandatory, no matter if table 5, 6 or 7 is applied. But it doesn’t seem to be the initial willing.

Delete the reference to 6.1.2.3 a) by replacing the sentence: “For such enclosures the requirements of 6.1.2.3 a) shall additionally apply.” with “For such enclosures the clauses of IEC 60079-0 identified in Table 1 additionally apply. »

Accepted in principle. Additionally the reference to Table 1 is kept.

FR-07

993 6.1.3 a) te 6.1.3 doesn’t clearly state if non-conductive dust (group IIIA and IIIB) are able to impair the

Add a note to clarify the requirements: Accepted in principle. By addressing requirements

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(e.g. Table 1)

Type of comment


intrinsic safety when clearance or creepage are important for safety. Different ExCB/ExTL have not the same interpretation. Some ExTL perform the enclosure test of 60079-0, and some other not.

“Note: even if considered not conductive, dusts classified in group IIIA or IIIB are able to impair infallible creepage or clearance.” (Or the opposite…)

for Group IIIA/IIIB and IIIC in different clauses, the distinction is made.

GB-064

1000 6.1.3 ed This sentence basically says that 6.1.2 applies, not 6.1.3. A change of the titles would be a less convoluted means of achieving the same thing.

Delete sentence Add to end of 6.1.2 title “or Group III associated apparatus”. Change 6.1.3 title to “Enclosures for Group III intrinsically safe apparatus”.

Accepted in principle. Differentiation between Group IIIC and other combustible dusts is made additionally.

DE-059

1006 -1008

6.2.1 2nd para Te The requirements in this para are ambiguous. While the first para requires a separation between IS and non-IS circuits, requires this para to apply the same methods for “all” external wiring to conductors or components without distinguishing between IS and non-IS. This would e.g. require to separate external IS terminals by a minimum distance of 50 mm to any IS circuit in an IS apparatus which has an IP20 enclosure only.

Delete this para or modify it to read: These methods of separation shall also be applied where intrinsic safety can be impaired by external wiring of non-intrinsically safe circuits, which, if disconnected from the terminal can come into contact with conductors or components of intrinsically safe circuits, which are not protected by an enclosure meeting the requirements of at least IP20 according to EN 60529.

Accepted in part. Addition of “non-intrinsically safe” not accepted as this needs to apply between IS circuits where intrinsic safety can be impaired by their interconnection. EN changed to IEC.

US-023

1009 6.2.1 Note 1 ed Delete this note as it is obvious, unnecessary and includes a recommendation in violation of IEC requirements for notes.

Delete Note 1. Accepted

GB-065

1013 6.2.1 Note 2 ed The note is applicable only to a) Indent to align with “Where separation is” Accepted

DE-060

1031 -1033

6.2.1 3rd para Ed This para describes the constructional requirements for clearance and creepage distances to be met in the design. To be consistent with figure 1a, Key T, the para should be re-worded

The clearances and creepage distances between the bare conductive parts of terminals of separate intrinsically safe circuits and to earthed or potential-free conductive parts shall be in accordance with 6.3.

Not Accepted: Text of 6.2.1 unchanged. Figure 1 aligned with text of 6.2.1, 3rd para (T = distances of Table 5) See revised new Figure 1.

DE-061

1040 to 1060

6.2.1 Figure 1a and 1b

Ed Figure 1b mostly repeats the content of the first figure of 1a, but uses a separate key. In figure 1a the 3D view, contrary to the 2D view, requires also 6 mm separation between the terminals of the second I.S. circuit. Figures in 1a and 1b should be combined and only use one key.

Consider if the proposed new figure (see attachment) can be used to replace Figures 1a and 1b

Accepted

US- 1041 6.2.1 Figure 1a ed All the elements of this figure appear to be better Delete Figure 1a. Retain and renumber Figure 1b Accepted

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(e.g. Table 1)

Type of comment


024 covered in Figure 1b. to Figure 1.

DE-062

1065 -1066

6.2.2 ed Better phrase Plugs and sockets for connection of external intrinsically safe circuits shall be separate from – and non-interchangeable – with those for connection of non-intrinsically safe circuits.

Accepted in principle “…shall be separate from, and non-interchangeable with, those for…”

CH-20

1067 6.2.2 te This requirement is not limited to intrinsically safe circuits alone. Connectors of intrinsically safe circuits and non-intrinsically safe circuits should be non-interchangeable. This might be achieved by keying, marking, ….

… Where intrinsically safe or associated apparatus is fitted with more than one plug and socket for external connections of intrinsically safe circuits and interchange could adversely affect intrinsic safety, such plugs and sockets shall either be arranged, for example by keying, so that interchange is not possible, or mating plugs and sockets shall be identified, for example by marking or color coding, to make interchanging obvious. …

Accepted in principle “of intrinsically safe circuits” was added to address comment US-048 on 31G/248/DC, because there was an identified conflict between the first two paragraphs. MT notes however, that multiple non-IS circuits are possible and could impair intrinsic safety if interchanged. Clause rearranged to address this comment and also US-048 on the DC.

DE-063

1075 6.2.2 3rd para Ed Refer to 6.3. instead of Table 5 …then the connection facilities need only to be in accordance with 6.3.

Not accepted: See DE-060 and revised Figure 1

DE-064

1078 -1092

6.2.3 ed Suggestion: earth terminals as sub clause of terminals (6.2.1). Thus type of connection is clearly separated in two clauses: terminals and connectors, too.

6.2.1 Terminals 6.2.1.1 Terminals carrying IS or NON-IS circuits 6.2.1.2 Earth terminals 6.2.2 Plugs and sockets

Accepted

US-025

1088 6.2.3 Par 1 ed Let’s make it easier for folks to find the info in 79-7 by calling out the section title.

Terminals which comply with the requirements of Electrical connections as stated in IEC 60079-7 are considered to comply with these requirements.

Accepted in part, added “for electrical connections”

BR-03

- 6.2.5 3rd te The non-hazardous area accessory may include means to limit the parameters for rating the infallible components in the intrinsically safe apparatus. The components used in the non-hazardous area accessory are assessed according to the IEC 60079-11, as given on this paragraph. Therefore, the requirements for marking these accessories should be given on this standard as well. Um should be possible to be marked in the accessory as it can vary, e.g. chargers for batteries may be specified with Um = 120 Vdc (maximum SELV voltage), which would

Include on this paragraph that the non-hazardous area accessory is also marked according to the clause 11. The Um at the connection facilities of the accessory shall be assumed to be the normal mains supply voltage e.g. 250 V a.c. unless marked otherwise.

Accepted in principle, not using the term Um as it is not an associated apparatus.

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(e.g. Table 1)

Type of comment


be the specification for the adapter and include means to limit this voltage to the Um marked in the apparatus.

GB-066

1099 6.2.5 te Charging circuits for cells and batteries need to be defined as over-charging can cause failures after the charger has been removed.

Refer to IEC TC31 WG37 for input. Accepted in principle. Charging of secondary cells and batteries shall only be done within the limits specified by the cell or battery manufacturer and defined in the secondary cells table of IEC 60079-0.

DE-065

1099 to 1132

6.2.5 Ed/te The current 6.2.5 is not structured well This is an attempt to restructure the chapter in a way that the first part of the chapter only contains requirements related to protection of circuits in the intrinsically safe apparatus to prevent the delivery of ignition capable energies when used in the hazardous area. The 2nd part lists requirements that ensure that Um at the terminals of the intrinsically safe apparatus is not exceeded when the apparatus is connected to accessories outside the hazardous environment. Proposed changes in detail: 1st para remains unchanged Delete 2nd para (DE comment on 1105) 4th para (unchanged) moved up: 2nd para 5th para moved up: 3rd para (revised to address DE comment on 1129) 5th para 2nd sentence moved up: 4th para 3rd para, 1st sentence moved down: 5th para “X” marking deleted (see comment on 1109) 3rd para 3rd sentence moved down: 7th para 3rd para 4th sentence moved down: 8th para Move text of 1133 into the example (see DE comment on 1111)

See proposal for revised text of chapter 6.2.5 in the Annex

Accepted in principle, see revised text

US-026

1099 6.2.5 te Is it intended that the accessory is marked with some minimum information – e.g. Certificate number?

Specify marking requirements in the clause. Accepted in Principle see new 11.3

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(e.g. Table 1)

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GB-067

1101 6.2.5 te Clarify that this also applies to wireless charging. Add “(including galvanically isolated)” after “connection facilities”.

Accepted in principle, Full sentence and Example added to revised text

GB-068

1103 6.2.5 ed The set of values is a “rating” according to 79-0. Change “ratings” to “rating” Accepted

GB-069

1105 6.2.5 te 7.11.9 contains the same requirements as the 4th paragraph (1119-1121) (except limited to charging connections) so there is no need to reference it.

Delete paragraph. Accepted see DE-066 and revised text

DE-066

1105 6.2.5 2nd para Ed / te The reference to 7.11.9 does not add any information to what is in lines 1119 to 1121. It was not contained in the proposed TG text.

Delete 2nd para Accepted

GB-070

1106 6.2.5 te Either the non-hazardous area connection is defined by Um, or it is a specialist accessory without intrinsic safety parameters. As worded, the current 6.2.5 attempts to achieve both at the same time which is impossible where the protection is provided by Um and not a specific accessory.

Change: Protection of the intrinsically safe apparatus shall be achieved by either of the following: a) The specification of Um for the connection.

This shall be stated in the certificate and marked on the intrinsically safe apparatus.

b) A specified accessory. This. circuitry and components may reside in either the intrinsically safe apparatus or a non-hazardous area accessory. If any part of the protection circuit is located in the non hazardous area accessory, the accessory shall be listed in the certificate and… the certificate number for the intrinsically safe apparatus … etc.

Indent EXAMPLE and NOTE 1 as they only apply to b) Move NOTE 2 to below a) and indent as it only applies to a).


GB-071

1108 6.2.5 3rd Paragraph

ed Comma missing Change to: “in the certificate, the certificate” Accepted

IT-05 1108 6.2.5 ed “… in the certificate the certificate number …” “… in the certificate and the certificate number …” Not accepted, see GB-071

US-027

1108 6.2.5 Par 3 ed Missing a conjunction Add the word “and” in the middle of these words: “the certificate the certificate”. Should read: “the certificate and the certificate”.

Not accepted, see GB-071

FR-08

1108 6.2.5 3rd te Separate the 2 sentences with a dot. “the accessory shall be listed in the certificate. The certificate number for the intrinsically safe

Accepted in principle, not relevant with modified text.

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(e.g. Table 1)

Type of comment


apparatus shall include the "X" suffix”

DE-067

1109 ff

6.2.5 3rd para, 2nd sentence

Te Requirement for an “X” is new. We do not see the necessity for an “X” if the non-hazardous area accessories are already listed in the certificate.

Delete: “the certificate number for the intrinsically safe apparatus shall include the "X" suffix in accordance with the marking requirements of IEC 60079-0 and the Specific Conditions of Use listed on the certificate shall detail the permitted accessories. 2nd sentence reduces to: “If any part of the protection circuit is located in the non hazardous area accessory, the accessory shall be listed in the certificate.”


DE-068

1111 6.2.5 te IEC60079-14 lists requirements for supply circuits for Um below 250V in chapter 16.2.1. Since the requirements listed in 6.2.5 of this draft are for equipment connected outside the hazardous environment it seems appropriate to adopt these requirements for chargers as an alternative to the use of a single Zener diode and fuse

….Countable fault analysis of 5.2 is not required for the non-hazardous area accessory, although protection components shall comply with the safety factor requirements of 7.1 after the application of non-countable faults. EXAMPLE: A fuse and suitably rated single Zener diode fulfill the requirement for voltage limitation. Alternatively IEC 60079-14 provides requirements for derivation of Um below 250 V a.c..


GB-072

1118 6.2.5 te Clarify that there are no requirements for marking of the non-hazardous area accessory.

Add: NOTE n: This standard does not require the non-hazardous area accessory to have any specific markings,

Not Accepted, see US-026

US-028

1127 6.2.5 5 / item b) te Delete the word “charging” as the contacts in question may not be used for charging.

“…distances between the charging contacts shall…”

Accepted

DE-069

1129 6.2.5 Last para ge The requirement to mark Um on the intrinsically safe apparatus should only be required where the certificate does not restrict the non-hazardous area accessories. Where the accessories are already restricted and listed in the certificate and part of the protection circuit is in the accessory the information of Um is redundant. We see a risk that stating Um would be counterproductive and could invite to connect eg chargers or cables other than the ones listed in the certificate.

Change 1st sentence: “Where the intrinsically safe apparatus connection facilities are not restricted to the use of an accessory listed in the certificate, the maximum voltage Um, which can be applied to these connections, shall be stated in the certificate and marked on the apparatus.”


GB-073

1129 6.2.5 ed For the last paragraph, defining a default Um is redundant as Um has to be marked on the apparatus anyway.

Delete the last paragraph (“The maximum voltage Um”)

Accepted

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(e.g. Table 1)

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RU-02

1132 6.2.5 T e To reword the sentence as follows: NOTE 2: IEC 60079-14 provides requirements for installation if Um is less than 250 V a.c.

Accepted

JP-20 1134 1448

6.3 6.4

ed To make the structure of the clause 6 better, Cl 6.4 should be before Cl 6.3, which makes the flow as follows. 6.1 Enclosures 6.2 Connection facilities for external circuits 6.3 Internal connections and connectors 6.4 Separation of conductive parts 6.5 Encapsulation 6.6 Specification of materials …

Exchange the positions of Clause 6.3 and 6.4. Accepted

GB-074

1134 6.3 te The GB committee is generally in agreement with the principle outlined in the Maintenance Team Note, however the GB Committee is also concerned about how this would be implemented especially in regard to the application of pollution degree which could be different in different parts of a circuit. How would this be implemented by users? Will guidance be provided for users in the installation standards?

IEC TC31 WG32 to proceed to generate the necessary spacings based on IEC 60664-1. In addition to assist in the development the requirements for users and for installation.

Noted.

CH-21

1135 6.3 te CH position has not changed since comment on 31/1198/DC was sent. We do not support the approach to replace existing spacing in TC31 standards. We do not see in general the need to make maintenance teams applying the rules given by WG32, neither as mandatory rules nor as alternative options. The philosophy of intrinsic safety is based on the energy limitation of the circuits itself and refers to enclosures as part of the protection only as a secondary means, which is the major difference between intrinsic safety and most of the other types of protection. By introducing the requirements and conditions of use as laid down in the IEC 60664 series in combination with tests described in IEC 60079-0, the importance of the enclosure as part of the type of protection increases which is likely to change the philosophy of intrinsic safety in a way

We propose to keep the assessment of equipment complying with Table 5 separated from assessment of equipment complying with Table 6, Table 7 or the future proposal based on the requirements and conditions of use as laid down in the IEC 60664 series. The assessment based on spacing requirement system with Table 5 shall remain in the main body of the standard whereas the assessment based on the requirements and conditions of use as laid down in the IEC 60664 series should be described in a normative annex. We do not support the approach to remove the assessment in compliance with Table 5 in future editions, after edition 7. By starting a new approach based on the work of TC31 WG32, we assume it to be necessary to align these requirements together with Table 6 and Table 7 in the normative annex. We assume two alternative methods to be enough.

Noted

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(e.g. Table 1)

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that limits its possibilities as type of explosion protection. Nevertheless, we would support the suggestion of TC31 WG32 laid down in 31/1198/DC as a base for a new draft of an alternative spacing requirement system described in a normative annex in IEC 60079-11.

AU-18

1135 6.3 ge AU in principle supports the inclusion of new creepage and clearance tables which align with 60664-1 as will be developed by WG 32. AU also supports the retention of existing Table 5 and Annex F tables as ‘legacy’ requirements in a suitable normative annex. AU would also support provision for interpolation of distances for voltages between the stated steps. AU further supports the inclusion of distances to fill in the blanks in Table 5 up to 15.6kV.

Noted

GB-075

1144 6.3.1 1st para ed These bullet points are part of the same sentence so should not lead with capitals

Change leading capital letters to lower case. Accepted

GB-076

1146 6.3.1 3rd bullet te Make clear that separation is required across current limiting components.

Add before “or”: “for examples, across current limiting components”

Accepted

IT-06 1147 6.3.1 4 item in the list

ed/te “ A circuit and earthed or …. “ Which kind of circuit?

“ Intrinsically safe circuit and earthed or .. “ Not accepted The leading sentence states “where intrinsic safety depends on the separation”. There may be instances where separation is required in the non-IS circuit (e.g. 250V to an isolated metal part to ensure suitable separation to the IS circuit near that part).

GB-077

1148 6.3.1 1st para te Although there are exceptions, there is a general principle that separation distances inside components are not considered. Whether failure of such components is a countable or non-countable fault is a matter for clause 7. This proposed change is in effect a replacement

Add: Unless stated otherwise in this standard, the requirements of 6.3 do not apply inside a component which is encapsulated or hermetically sealed, for example a semiconductor.

Accepted in principle, change to: The requirements of 6.3 apply to internal separations within components unless stated otherwise in this standard.

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(e.g. Table 1)

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for Ed.6. 6.3.5 last para (currently in 7.2).

DE-070

1160 - 1163

6.3.1 Para above Note 3

Te Here is a contradiction. This clause says no separation requirements whereas 6.3.7 has separation requirements.

Change to “Separation distances shall be applied as described in 6.3.7 where earthed metal…”

Accepted in principle,.see CH-22

CH-22

1160 6.3.1 te There are circumstances which require the application of clearance though the two circuits are separated by an earthed screen

Separation requirements, except clearance described in 6.3.7, shall not apply where earthed metal, for example tracks of a printed circuit board, a screen or a partition, separates an intrinsically safe circuit from other circuits, provided that breakdown to earth does not adversely affect intrinsic safety and that the requirements of 6.3.7 are fulfilled.

Accepted in principle, paragraph and note 4 deleted as they are no longer necessary. Added a new first paragraph to 6.5.7 and moved note 3 to after this paragraph, and modified note.

CH-23

1168 6.3.1 te Though Table 5 is not introduced Table 6 and Table 7 are explained with respect to Table 5. The structure as it is chosen does not seem to differentiate sufficiently between the assessment in compliance with Table 5 and the assessment in accordance with Table 6 and Table 7. The benefit from moving Annex F into clause 6.3 is not yet obvious. It seems that the merger of the two systems, on in compliance with Table 5 and the other based on the requirements and conditions of use as laid down in the IEC 60664 series leads to confusion. Note 5 seems to be better located in an annex than in the main body of a standard.

Consider to relocate the assessment based on the requirements and conditions of use as laid down in the IEC 60664 series back to Annex F.

Accepted in part Restoring Annex F is not accepted Para added to introduce Table 5 in 6.5.1 and new subclauses 6.5.2, 6.5.2.1 for “reduced separation distances” See re-write of 6.5

AU-19

1174 6.3.1 Note 5 Ed The word “conceptually” in the second sentence of this note adds no value.

Delete “conceptually” Accepted in principle, note substantially simplified.

DE-071

1176 6.3.1 Te Actual and in future different types of separation components are possible

Relay, opto-coupler and other types of galvanic separating components…

Accepted in principle, note substantially simplified.

US-029

1176 6.3.1 Note 5 ed Reword for clarity. NOTE 5 The requirements for separation distances specified in Table 5 are based widely on pollution degree 3 (IEC 60664-1). Conceptually, a double or reinforced insulation based on IEC 60664-1 is considered to comply with safety separation requirements of intrinsic safety level “ia” and “ib” also. With When considering printed circuit boards, and relays and opto-couplers where either the pollution degree 2 is applicable due to installation conditions or by housing or coating

Accepted in principle, note substantially simplified.

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(e.g. Table 1)

Type of comment


with protection from ingress of dust and moisture, the requirements of Table 6 or Table 7 offer less onerous construction requirements. This alternative method takes advantage of "Insulation coordination for equipment within low voltage systems" (IEC 60664-1).

GB-078

1182 6.3.1.1 1st sentence ed “Level of Protection” is capitalised for consistency.

Capitalise Accepted

GB-079

1182 6.3.1.1 1st para te The wording makes Table 6 seem only applicable to “ia” and “ib” mains powered associated apparatus. The “non-mains/mains circuits” in relation to overvoltage category is in conflict with IEC 60664-1 4.3.3.2.1 which states that overvoltage category is only applicable to mains equipment. Hence this needs deleting.

Add new paragraph and modify existing 1st paragraph as follows: Apparatus meeting the separation requirements of Table 6 for Levels of Protection “ia” and “ib” shall comply with the following. For mains powered associated apparatus, distances in Table 6 for levels of protection “ia” and “ib” are applicable provided that the circuits are the mains power shall be limited to overvoltage category I, /II or III as defined in IEC 60664-1 (non-mains/mains circuits). In this case the overvoltage categoryThis shall be included in the documentation provided by the manufacturer as a condition of installation. The certificate number shall include the "X" suffix in accordance with the marking requirements of IEC 60079-0 and the Specific Conditions of Use listed on the certificate shall detail the installation requirements.

Accepted in principle: Text modified to also address CH-24, DE-072, DE-073

CH-24

1182 6.3.1.1 te ‘For mains powered associated apparatus, distances in Table 6 for levels of protection “ia” and “ib” are applicable provided that the circuits are limited to overvoltage category I/II or III as defined in IEC 60664-1 (non-mains/mains circuits).‘ The text gives the impression that overvoltage category III is a limitation compared to standard mains which should require Specific Conditions of Use. This is not the case.

Change the word “limited” to “classified” and change the second sentence. For mains powered associated apparatus, distances in Table 6 for levels of protection “ia” and “ib” are applicable provided that the circuits are classified to overvoltage category I/II or III as defined in IEC 60664-1 (non-mains/mains circuits). In case of overvoltage category I or II, the overvoltage category shall be included in the documentation provided by the manufacturer as a condition of installation.

Accepted in part: Change to “classified” is not accepted; “limited” makes more sense. “X” condition only if limited to OC I or II.

DE-072

1182 6.3.1.1 First Para Te Why only “mains powered associated apparatus”? This table may be used also to any other apparatus provided the conditions are met

Delete “for mains powered associated apparatus” Accepted in principle: Text modified to also address GB-079

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(e.g. Table 1)

Type of comment


(non mains powered or even intrinsically safe apparatus)

DE-073

1182 6.3.1.1 First Para Te Not only OC is important also PD is decisive for applying table 6. Add reference to clause 6.1.2.3

Change to “…distances in Table 6 for levels of protection “ia” and “ib” are applicable provided that the requirements of clause 6.1.2.3 are met and the circuits are limited to overvoltage category I/II or III as defined in IEC 60664-1 (non-mains/mains circuits).”

Accepted in principle: Text modified see GB-079 Reference to 6.1.2.3 and 6.1.3 now in new 6.3.2.1

GB-080

1189 6.3.1.1 2nd para te Requirement for routine tests as required by IEC 60664-1 and IEC 60664-3 is a circular requirement as these documents (6.1.2.2.1.2 in the former and 5.1 in the latter) state that it is up to the technical committee (i.e. MT60079-11) to decide which routine tests are necessary.

Modify text: Distance under coating, distance through casting compound and distance through solid insulation shall be subjected to type and routine testing as required in IEC 60664-1 and IEC 60664-3. , except that rRoutine tests are only mandatory where voltages exceeding 150 V rms or 150 V d.c. occur across separations.

Accepted in principle, requirement for routine test deleted.

CH-25

1189 6.3.1.1 te Type testing and routine testing is not required for clearance, creepage and coating of type 1. Routine testing can be omitted for voltages not exceeding 60 V rms or 85 V d.c..

Distance under coating of type 2, distance through casting compound and distance through solid insulation shall be subjected to type testing and routine testing as described in clause 9.3 to achieve compliance with clause 6.8 or the relevant industrial standard, except that routine tests are only mandatory where voltages exceeding 60 V rms or 85 V d.c. occur across separations.


US-030

1190 6.3.1.1 Par 2 te Several of the routine/type tests listed in IEC 60664-1 are incomplete and point to the technical committee to define test levels. (Ex. See 60664-1 Section 5.3.3.4 on Withstand of mechanical stresses) We need to consider which problem we are trying to solve and focus on ensuring we have type testing for that.

Add a statement to clarify, …as required in IEC 60664-1 and IEC 60664-3, for voltage withstand and temperature, except that routine tests…

Accepted in principle, but see discussion on GB-080

DE-074

1192 6.3.1 Te A limit of 150V rms/150V DC would allow to waive the routine test for mains voltages of e.g. 110V AC, was this the intended. Reduce the limit to 60V DC / 85V AC or delete the routine test for all voltages

Consider to either delete the requirement for routine test completely or to reduce the limit to voltages exceeding 60V rms or 85V d.c.


DE-075

1194 6.3.1 Te The most onerous condition can be the minimum, maximum temperature, air pressure (80…110kPA) ~21% +/- ??? oxygen, the influence is included of the high separations etc.

Delete “… for example the maximum and minimum temperatures”

Not accepted, but see discussion on GB-080

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(e.g. Table 1)

Type of comment


CH-26

1195 6.3.1.1 Reference to test conditions needs to be added Add after last sentence Type tests shall be carried out in accordance with 9.3, applying the voltages of 6.8 as applicable.


CH-27

1198 6.3.1.1 te Reference to test conditions needs to be added Modify last sentence Routine tests shall be carried out in accordance with 9.3, applying the voltages of 6.8 as applicable.


GB-081

1200 6.3.1.1 Note te This note is permission not to apply tests of IEC 60664-3 so should not be a note. The English is also not quite right.

Modify: NOTE: Opto-couplers specified as meeting the requirements for safe electrical insulation according IEC 60747-5-2 or IEC 60747-5-5 and rated to match with for the dielectric strength required in the application, do not need testing according IEC 60664-3, because the tests of IEC 60747-5 cover this equally are sufficient. This alsoSimilar applies for R to relays and other types of coupler providing reinforced insulation according to IEC 61810-1 or other type of coupler.

Accepted in part: Text becomes normative. Text modified to reference to 7.9 instead of repeating what is covered there. “other type of coupler” with reference to 61810-1 (on Relays) not accepted as the generic term “signal isolator” has been used throughout.

US-031

1200 6.3.1.1 Note te This should not be a note as it waives a test requirement

NOTE Opto-couplers specified meeting the requirements for safe electrical insulation according IEC 60747-5-2 or 60747-5-5 and rated to match with the dielectric strength required in the application…

Accepted in principle, see GB-081

US-032

1202 6.3.1.1 Note ed The last sentence, “Similar applies for relays…”, of this note doesn’t read correctly.

Change to “Similarly, this applies to relays or other types of couplers, which provide reinforced insulation according to IEC 61810-1.”


GB-082

1205 6.3.1.1 Last para te This sentence seems more applicable to the “composite separations” subclause.

Move to end of 6.3.5 (not 6.3.7). Accepted in principle: Sentence moved to 6.3.5 (now 6.5.6) and modified by deletion of “”as provided in 6.3.5”

DE-076

1205 6.3.1.1 Last Para Ed Composite separations is clause 6.3.5 not 6.3.7. However, why is this not possible when using table 6?

Correct to 6.3.5 or consider moving this sentence to clause 6.3.5.


CH-28

1205 6.3.1.1 ed Composite separations are described in 6.3.5 and not in 6.3.7.

Composite separations as provided in 6.3.5 shall not be applied when using Table 6.


GB-083

1207 6.3.1.2 1st para te The wording makes Table 7 only applicable to mains powered associated apparatus. It is not clear how “either in the apparatus or

Add new paragraph and modify existing 1st paragraph as follows: Apparatus meeting the separation requirements of

Accepted in principle: Proposed new 1st para

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(e.g. Table 1)

Type of comment


external to the apparatus” relates to the definitions for overvoltage categories in IEC 60664-1. Maybe this is overvoltage category I limitation of the overvoltage which may take place internally, in which case Table 7 should only be used following the limitation.

Table 7 for Levels of Protection “ic” shall comply with the following. For mains powered associated apparatus, distances in Table 7 are applicable for Level of Protection “ic”, provided that the circuits, either in the apparatus or external to the apparatus, are the circuits shall be limited to overvoltage category I or /II as defined in IEC 60664-1. Provision to limit the overvoltage may be internal or external to the apparatus provided that the use of Table 7 is only applied on the limited circuits.

added. Wording 1st sentence 2nd para lined up with 6.3.2.2. Extension of 2nd sentence not accepted, due to repeating requirement of 1st sentence

DE-077

1207 6.3.1.2 First Para Te Why only “mains powered associated apparatus”? This table may be used also to any other apparatus provided the conditions are met (non mains powered or even intrinsically safe apparatus)

Delete “for mains powered associated apparatus” Accepted in principle, see GB-083, adding a new 1st para.

DE-078

1207 6.3.1.2 First Para Te Not only OC is important, also PD is decisive for applying table 6. Add reference to clause 6.1.2.3

Change to “…distances in Table 7 are applicable for levels of protection ”ic” provided that the requirements of clause 61.2.3 are met and the circuits are limited to overvoltage category I/II as defined in IEC 60664-1.”

Not accepted. New 6.3.2.1 solves the issue

DE-079

1213 6.3.1.2 Te Add an exclusion like line 1205 Composite separations as provided in 6.3.5 shall not be applied when using Table 7.

Not accepted: Ed. 6 did not exclude composite separations using Table F.2 and 6.3.5 contains a requirement for “ic”

US-033

1217 6.3.2.2 1 ed Reword for clarity. 6.3.2.2 Infallible separations Separation distances other than those related to connection facilities that comply with the values of Table 5 protected by an enclosure of at least IP20 or Table 6 or Table 7 under the conditions of 6.1.2 or 6.1.3 shall be considered infallible against a failure of separations except when exposing connection facilities also exposes separations not protected by solid insulation or encapsulation. where the separation is not provided by solid insulation or encapsulated or covered by a coating in accordance with this standard or is not protected by an enclosure with a rating of at least IP20.

Accepted in principle: Para split to improve readability, reference to 6.1.2 and 6.1.3 instead repeating part of 6.1.2.2.

DE-080

1220 -1222

6.3.2.2 ed Exception unclear Positively statement: If IS signals are fix (e.g. PCB) and protected by

Accepted in principle, see US-033

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(e.g. Table 1)

Type of comment


enclosures IP rating 20 or better and not part of connection facilities the distances of table 5, 6, 7 under conditions 6.1.2 and 6.1.3 shall be regarded as infallible.

US-034

1230 6.3.2.3 3 ed This concept is better and more generically covered in section 6.3.5 on composite spacings. If we retain this section, expand to cover ib as well as ia as this is talking about infallible separations, not spacings “subject to fault”.

Delete this paragraph as it is better covered in 6.3.5.

Accepted in principle, text modified and referenced to 6.3.5.

DE-081

1230 6.3.2.3 3rd Para Te Only ½ + ½ is Ok? I assume that according figure 3 (lower left picture). Also 1/3 + 2/3 would be OK. Rewrite this paragraph.

Change to “For level of protection “ia”, smaller separation distances, which are less than the values specified in Table 5 but greater than or equal to one-third of that value, shall not be subject to a fault if a second separation distance is effective, and adding these two separations distances results in the complete required value specified in Table 5. The second separation distance shall also be greater than or equal to one-third of the values specified in Table 5.”

Accepted in principle proposed text to be merged into 6.3.5 and a para added to 6.3.3.3 to cover the fault assessment, in case of adding up 2 sections.

AU-20

1230 6.3.2.3 3 te The paragraph states that compounded separation distances equal to or exceeding table 5 are not subject to any fault and hence therefore inferred as infallible. However, with the current wording, the 2nd distance described could still be subject to the spark test apparatus which can apply to internal distances less than table 5, 6 or 7. The spark test apparatus is effectively applied across a compounded distance greater than table 5,6 or 7 and 9.1.2 states the spark test apparatus shall not be used across infallible separations Add text to clarify that the distance that is not subject to fault is infallible to ensure the spark test apparatus cannot be applied across compounded distances greater than table 5, 6 or 7. Also reworded for clarity.

Replace paragraph with: For Level of Protection “ia”, a composite separation, comprised of two separations which are both less than the values specified in Table 5, but greater than or equal to one-half of that value, shall be considered infallible. One of the two separations is considered as subject to a countable short circuit fault if this impairs intrinsic safety.

Accepted in principle, added new 2nd para to apply only one fault. see US-34 and DE-081 Note that Table 6 or 7 do not allow the 1/3 rule and Table 6 excludes composite separations

BR-04

1230-1234

6.3.2.3 3rd ed This paragraph should be rephrased as it is not clear what would be a “second effective separation distance”. It seems that if for example two resistors are in series and both provide a

Rephrase this paragraph with a clear explanation of how the one-half combined faults should work to avoid confusion when applying this requirement, ensuring therefore alignment in the interpretation.

Accepted in principle, see US-34 and DE-081

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(e.g. Table 1)

Type of comment


separation distance greater than or equal to one-half of the values in the Table 5, then the countable fault condition applies to one of the two resistors and the other can be considered segregated. However, it is not clear this interpretation.

DE-082

1230 to 1234

6.3.2.3 Ed The sentences are too complex. Reduce the complexity. There is no senseful application recognizable.

“…that value specified in Table 5.” A composite separation with two one-half separations is infallible”

Not accepted, reworded by US-34 and DE-081

GB-084

1230 6.3.2.3 3rd para ed “Levels of Protection” should be capitalised for consistency.

Capitalise. Accepted

GB-085

1236 6.3.2.3 4th para te “ic” transformers do not require Table 5 (or Table 7) separation which is a contradiction to this requirement.

Add to end “unless otherwise stated in this standard”.

Not accepted. 4th para move up to 6.3.1 Note that separation requirements inside components are in the subject clauses.

AU-21

1239 6.3.2.4 1 te Clearly define the type of fault. Modify the text: For Levels of Protection “ia” and “ib”, if separation distances are less than the values specified in Table 6, they shall be subject to a non-countable fault if this impairs intrinsic safety. However, where redundancy of components is required (for example two capacitors in series), separation distance of less than the full value but greater or equal to half the value according to Table 6 shall be considered as a single countable fault; no further faults to be considered.

Accepted

DE-083

1241 6.3.2.4 Te There is contradiction for blocking capacitors. 7.4.3 with 7.4.2 requires external distances at the capacitor to comply with 6.3. 6.3.2.3 (Table 5) in 3rd para accepts, that the total distance may add up from two halves, with a short circuit of one to be a countable fault. But the second fault from 7.4.3 shorting the a capacitor results in shorting the assembly. 6.3.2.4 (Table 6) however, states that one half of the distance is sufficient for blocking capacitor assemblies and the short of that distance to be the only fault applied.

Consider lining up the two clauses either to accept half distances at each capacitor or to require the full distance at each capacitor.

Not Accepted - MT agrees with the principle but does not have a proposal.

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(e.g. Table 1)

Type of comment


GB-086

1245 6.3.2.5 1st para te “ic” transformers do not require Table 7 separation, and Table 7 does not need to be met for < 60 V (per 6.3.1.2) which is a contradiction to this requirement.

Add to end “unless otherwise stated in this standard”.

Not accepted 6.3.2.5 is deleted anyway, and contained now in 6.3.1; see GB-085

RU-04

1246 6.3.2.3 Table 5 te In the first column of Table 5 the voltage range should be specified: «⩽10», «from 10 up to 30», etc

Not accepted other IEC standards are written the same way.

DE-084

1246 6.3.2.3 Table 5 Ed Use the same type of voltage type, only rms, or Upeak or U d.c. in the tables 5, 6, 7

Not accepted It is intended that Tables 5, 6, and 7 will be replaced and retained only for legacy purposes. No changes to these Tables will be made.

DE-085

1246 6.3.2.3 Table 5 Ed No tolerances? In table 6 a 10% tolerance is allowed in NOTE 1, Note 2 and Note 5 of table 6 make’s also sense at table 5

Add “maximum” to the voltage values, Add note 2 and note 5 of table 6


DE-086

1249 6.3.2.4 Table 6 Ed Title of Table 6 is too long and should be revised Table 6 - Clearances, creepage distances and separations for Level of Protection “ia” and “ib” for pollution degree 2

Accepted in principle; “for pollution degree 2” deleted as well

US-035

1250 Table 6 Title ed Special conditions of material and installation must be met for this table to apply however we are not explicitly calling out what these special conditions are. The places where we use the word “special” in this standard typically refers to items not covered or defined in the standard, yet we still point to some annex or clause or provide an example to clarify the meaning of “special”.

Define what we mean by the special conditions. If we are just saying they need to comply with what is stated in Section 6, then remove the word “special”.

Not accepted; issue solved with DE-086 on shortening the title. Details on the conditions are in 6.1.2, 6.1.3 and 6.3.

DE-087

1251 6.3.2.5 Table 6 Te According figure 2 most of the distances where table 6 could be used is on secondary side or in IS-circuit. Term of overvoltage category out of IEC 60664-1 relates to mains. So most of the circuits where the distances are used, are derived from mains. Additionally specifying OC inside a intrinsically safe circuit makes no sense.

Provide clearances based on the expected overvoltage present at that part of the circuit. E.g >500V after voltage limitation

Not accepted, no proposal It is intended that Tables 5, 6, and 7 will be replaced and retained only for legacy purposes. No changes to these Tables will be made.

US- 1251 Table 6 Column 6 ed Column 6, definition of Type 2 protection in IEC Remove column 6 and any references to Type 2, Not accepted

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(e.g. Table 1)

Type of comment


036 60664-3 appears to have the similar meaning as solid insulation so this column is redundant. Actually, in 60664-3, Type 2 appears to encompass both solid insulation as well as casting compound, (see note in section 5.6). I’d think that we’d also want this type 2 protection to pass all dielectric strength tests as defined for solid insulation? Or are we saying that we just need to do partial discharge test on this material as defined in 60664-1? Maybe it depends on if it is solid insulation or casing compound.

even in the note because it is not clearly defined in 60664-3, whereas 79-11 defines solid insulation vs. casting compound and defines testing & other requirements that are required for these materials.

It is intended that Tables 5, 6, and 7 will be replaced and retained only for legacy purposes. No changes to these Tables will be made.

DE-088

1251 6.3.2.6 Table 6 Ed Include the 10% tolerance to the voltage and call the Voltage Upeak (see table 5)


DE-089

1254 6.3.2.7 Table 7 Ed Title of Table 7 is too long and should be revised Table 7 - Clearances, creepage distances and separations for Level of Protection “ic” for pollution degree 2

Accepted in principle; “for pollution degree 2” deleted as well

US-037

1255 Table 7 Title ed Special conditions of installation must be met for this table to apply however we are not explicitly calling out what these special conditions are. The places where we use the word “special” in this standard typically refers to items not covered or defined in the standard, yet we still point to some annex or clause or provide an example to clarify the meaning of “special”.

Define what we mean by the special conditions. If we are just saying they need to comply with what is stated in Section 6, then remove the word “special”.

Not accepted; issue solved with DE-089 on shortening the title. Details on the conditions are in 6.1.2, 6.1.3 and 6.3.

US-038

1257 6.3.2 Figure 2 te The figure implies that the load circuit conductors should be separated in accordance with 6.2.1 but it is just the external terminals for the load that must be spaced per 6.2.1.

Revise the figure to clearly indicate that the terminals for the load must be separated per 6.2.1, not the circuit conductors/field wiring.

Accepted: Figure 2 to be revised. Arrow (9) between the two separate I.S. circuits moved left to be between the terminal symbols (not the screens)

DE-090

1265 6.3.2.4 Figure 2 Te Table 6 and 7 are not allowed for transformers, therefore the explanation (6) is not correct at the distances of the shown transformers

New explanation (10) for the distances through transformers : “Dimensions to which table 5 is applicable”

Accepted in principle modify figure so that it is clear that the external separations are meant (e.g. adding component terminals) otherwise the issue occurs with the

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(e.g. Table 1)

Type of comment


coupler and resistors.

GB-087

1282 6.3.3 a) ed “the value of voltage to be considered between the circuits, shall be” is a repetition of line 1280 and is not consistent with the layout of b)

Replace “the value of voltage to be considered between the circuits, shall be” with a colon.

Accepted in principle, text slightly modified.

GB-088

1291 6.3.3 b) te This requirement attempts to second guess the result of the fault analysis, and is not always correct, for example where the two voltages are based on the same common mode voltage. “May” is normally used for permission so should be avoided for a possibility. There may be more than 2 voltages in the sum.

Reword: Between parts of a circuit: the maximum peak value of the voltage that can occur between the two conductive parts (which is normally the maximum voltage in either part of that circuit). This maycould be the sum of the voltages of different sources connected to that circuit: if this is the sum of two voltages, one of them . One of the voltages may be ignored if it is less than 20 % of the other.

Accepted in principle proposed text modified.

GB-089

1295 6.3.3 3rd para te The maximum voltage might be in normal operation

Replace “the fault conditions of” with “the conditions specified in”.

Accepted

GB-090

1296 6.3.3 Last para te External voltage might be from a non-hazardous area accessory that does not have Um defined.

Add to end of sentence “or the maximum voltage as defined by the protection components of a specified non-hazardous area accessory”.

Accepted

DE-091

1296 -1299

6.3.3 Ed The fuse that opens the circuit is the protection Delete the comma after “fuse” and add a comma after “circuit”

Accepted in principle, entire example moved to after “circuit”

AU-22

1297 6.3.3 Para 4 Te This paragraph refers to “transient voltages such as might exist before a protective device” and that they need to be considered when evaluating clearances. This does not conform to the definition of “transient voltages” in this standard which only apply to those “that occurs within the circuit as a result of applying faults or with Um or Ui applied”, as it appears to consider external transient voltages. Particularly for Um, this has been an item of concern in Australia, as it is unclear whether a supply voltage is permitted to exceed Um under transient conditions (e.g. network switching), and if so, what transient magnitude/duration/frequency is acceptable.

Consider change to this clause, as well as the definition of Um and in Clause 5 (line 734).

Accepted in part, sentence deleted. The MT did not feel a change to the definition of Um is necessary.

DE-092

1298 1299

6.3.3 4th para, last sentence

te There is no source of information how this requirement has to be met. Comparing the requirements of 60664-1, shows

Modify the sentence: “Transient voltages such as might exist before a protective device, for example a fuse, that opens the circuit shall not be

Not accepted. Instead, the TG proposes to delete " Transient voltages such as might exist before a

Jason Wigg

Not actioned?

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(e.g. Table 1)

Type of comment


that the clearance values required in Tables 5, 6, 7 of -11 are sufficient for the level of transients expected for overvoltage categories III or II as applicable.

considered when evaluating separations.” protective device that opens the circuit, for example a fuse, shall not be considered when evaluating the creepage distance, but shall be considered when evaluating clearances. "

AU-23

1304 6.3.4.1 1 te Clearance can comply with table 6 or table 7 if requirements are met as per 6.1.2.3

Modify the text: Clearance distances shall comply with column 2 of Table 5, Table 6, or Table 7. Insulating partitions shall meet the requirements of 6.3.8 or shall be ignored, other insulating parts shall comply with column 4 of Table 5, Table 6, or Table 7.

Accepted in principle Change to “… other insulating parts shall comply with 6.3.4.3.”

GB-091

1302, 1304

6.3.4.1 1st Paragraph

te Table 6 and Table 7 seem missing on both lines. Change to: “Table 5, Table 6 or Table 7 as applicable.”

Accepted in principle, “as applicable” not required.

DE-093

1302 6.3.4.1 1st para Ed Reference to Table 6 and Table 7 is missing. Clearance is a defined term. Should be used without the addition of “distances”

Clearances shall comply with column 2 of Table 5 or Table 6 or Table 7.

Accepted in principle, grammatical changes

US-039

1302 6.3.4.1 1, 2 te Reword for clarity. Clearance distances shall that comply with column 2 of Table 5 shall be considered infallible. Insulating partitions shall meet the requirements of 6.3.8 or shall be ignored evaluated as not existing., other insulating parts shall comply with column 4 of Table 5.

Accepted in principle Change to “Clearance distances are given in …” Change to “… shall be considered not to provide separation …”

FR-09

1302 6.3.4.1 1st te Table 6 and table 7 could also be used for clearance distances

Modify the sentence: “Clearance distances shall comply with column 2 of Table 5, Table 6, or Table 7 as applicable”

Accepted in principle, “as applicable” not required.

US-040

1303 6.3.4.1 Par 2 te This could be read as a conflicting statement. Insulating partitions shall meet requirements of 6.3.8 or shall be ignored. I think if I were the designer, then I would choose to ignore, always. We need to clarify when this is mandatory.

Change to: “…requirements of 6.3.8 or shall be evaluated as not existing, …”


DE-094

1303 6.3.4.1 Ed. Partitions are described in 6.3.7 and 6.3.8. By doing this reference, pointing to column 4 of Table 5 is not needed.

Change to “Insulating partitions shall meet the requirements of 6.3.7 or 6.3.8 or shall be ignored, other insulating parts shall comply with column 4 of Table 5.

Not accepted, 6.3.7 is for earthed metal partitions, paragraph is for insulating partitions.

GB- 1309 6.3.4.2 te This does not give a general statement about Replace sub-clause with: Accepted in principle,

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(e.g. Table 1)

Type of comment


092 separation through casting compound. Add a note clarifying why creepage distances are not used (from Ed.6 D.1 2nd para).

Separation distances through casting compound that meets the requirements of 6.5.1 and 6.5.5 shall comply with column 3 of Table 5, Table 6, or Table 7. These separations also apply at the boundary between casting compound and solid insulation provided that the casting compound adheres to both the conductive parts and to the solid insulation. (e.g. tracks on a printed circuit board). NOTE The exclusion of creepage distance requirements here is due to the removal of the likelihood of contamination.

change to: Separation distances through casting compound are given in column 3 of Table 5, Table 6, or Table 7. These separations may also apply at the boundary between casting compound and solid insulation provided that the casting compound adheres to both the conductive parts and to the solid insulation. (e.g. tracks on a printed circuit board). NOTE The exclusion of creepage distance requirements through the casting compound is due to the removal of the likelihood of contamination.

US-041

1311 6.3.4.2 1 te Only infallible separations need comply with these requirements.

“…separation distances which meet per column 3 of Table 5, Table 6, or Table 7 apply are considered infallible.”

Accepted in principle, see US-039 and GB-092.

US-042

1313 6.3.4.3 1 te The first line of this section is a definition and should be moved to the definitions section. Reword the remainder of the clause for clarity.

6.3.4.3 Separation distances through solid insulation Solid insulation is insulation which is extruded or moulded but not poured.[move to definitions] Solid insulation relied on for intrinsic safety shall have a dielectric strength that complies with 6.8 and be dimensioned in accordance with 6.3.2. The maximum current in the insulated wiring shall not exceed the rating specified by the manufacturer of the wire.

Accepted in principle (definition is in 79-0) Also added: Separations through solid insulation are given in …

DE-095

1314 6.3.4.3 Te The first sentence reduce the solid insulation just to extruded or moulded, but it can also be a PCB, or other material.

Modify the sentence to: ”Insulation material extruded, moulded or the similar are considered solid insulation, while poured are not.”

Not accepted, sentence has been removed, see US-042

GB-093

1315 6.3.4.3 te Dielectric strength requirements of 6.8 are a general requirement and not specific to solid insulation. The requirement is between

Delete “have a dielectric strength that complies with 6.8 and”

Not accepted, 6.8 might not always apply if not called here.

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conductive parts, the insulation between which may be composite and not just solid insulation.

DE-096

1316 6.3.4.3 1st para, 2nd sentence

Ed/te Reference to 6.3.2 “Failure of separations does not work. In consensus to other clauses before refer to column 4 of Tables 5, 6 or 7

Change to: … and be dimensioned according to column 4 of Table 5, Table 6 or Table 7”.

Accepted in principle, text deleted as no longer applicable.

AU-24

1316 6.3.4.3 1 ge The requirements for insulated wiring should be moved to 6.3.9 Insulation of internal wiring

Modify the text: 6.3.9 Insulation of internal wiring Insulation, except for varnish and similar coatings, covering the conductors of internal wiring shall be considered as solid insulation (see 6.3.4.3). The maximum current in the insulated wiring shall not exceed the rating specified by the manufacturer of the wire. Delete “The maximum current in the insulated wiring shall not exceed the rating specified by the manufacturer of the wire.” from 6.3.4.3

Accepted in principle, text also modified as wire manufacturers do not usually specify a current rating.

DE-097

1316 6.3.4.3 1st par 3rd sentence

Ed/te This sentence seems to be misplaced. It should be moved to 6.3.9 “internal wiring” or alternatively added below to 3rd para of 6.3.4.3 (after line 1321)

Consider moving to 6.3.9 (preference) or to 3rd para of 6.3.4.3.

Accepted, see AU-24

DE-098

1318 6.3.4.3 Te Two pieces of insulation material fulfil the requirements of separation of two or three additional distances

Replace “…two…” to “…several pieces of identical electrical insulating material”

Not accepted, the clause already says “two or more” and there is no justification given for requiring identical material.

DE-099

1320 -1321

6.3.4.3 Ed Here is only the conductor (copper) meant – please clarify

Insulated wires that comply with the distance through solid insulation are not considered to jeopardize the insulation if the copper of the wire breaks.


FR-10

1321 6.3.4.3 3rd ed The end of the sentence seems to be erroneous Delete “should breakage of the wire occur” Accepted in principle, “wire” has been changed to “conductor”.

GB-094

1322 6.3.4.3 NOTEs te These notes are not dispensable supporting information, but are significant when applying the standard. The first note should be a recommendation, the second a requirement and the third permission.

Make normative text. NOTE 1 replace “is considered to be” with “should be”. NOTE 2: replace “are not considered to be” with shall not be considered” NOTE 3: replace “is” with “may be”

Accepted

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AU-25

1324 6.3.4.3 5 te Note 2 should be normative text in line with the similar normative text in 6.3.9 which only applies to internal wiring.

Make normative text and modify as: Varnish and similar coatings shall not be considered solid insulation.

Accepted

US-043

1328 6.3.4.4 ed Regardless of the column/table that creepage distances are specified in, the insulating material should comply with column 7 of the applicable table.

For the creepage distances specified in column 5 of Table 5, the insulating material shall comply with column 7 of Table 5 or Table 6 or Table 7 where applicable,

Accepted in principle, clause reworded.

DE-100

1328 6.3.4.4 1st para Ed/te Reference to Tables 6 or 7 is missing in the first part of the sentence. As creepage is specified in different columns specific wording is required

Change to: “… specified in column 5 of Table 5 or Table 7 or in column 2 of Table 6”


GB-095

1328 6.3.4.4 1st Paragraph

te Table 6 and Table 7 seem missing on fist line of paragraph.

Change to “For the creepage distances specified in column 5 of Table 5, Table 6 or Table 7, the…”


FR-11

1328 6.3.4.4 1st te Table 6 and table 7 could also be used for creepage distances

Modify the sentence: “For the creepage distances specified in column 5 of Table 5 or Table 7, or in column 2 of Table 6”

Accepted in principle, reference to Table 5 deleted as it is repeated at the end of the sentence with Table 6 and Table 7.

FR-12

1335 6.3.4.4 3rd te Partitions requirements are in clauses 6.3.7 and 6.3.8. It is more direct to make reference to these clauses, instead of reference to 6.3.1 (which reference to 6.3.8 in a simple note)

Change the reference as follows: In either case, the partition shall comply with 6.3.7 or 6.3.8, as applicable.

Accepted.

GB-096

1336 6.3.4.4 Figure 3 te Dimensions in Figure 3 drawings seem specific to table 5 while reference to Figure 3 allows Table 6 and Table 7 dimensions.

Remove specific dimensions Not accepted values in figure 3 are not derived from Table 5. In principle agreed to adopt figures from 60664-1 (also used in 60079-7) with suitable X values.

GB-097

1336 6.3.4.4. te Figure 3 dimensions only reflect “ia” and “ib” and do not address “ic”.

Add the text from 4.4.3. of IEC 60079-7:2015, modified for “ia”, “ib” & “ic”, possibly adopting the same values. Also replace Figure 3 with Figure 1 from IEC 60079-7:2015 as these examples are identical with those from IEC 60664-1.

Accepted in principle used figures from 60664-1 (60079-7)

DE-101

1336 6.3.4.4 Figure 3 Ed This figure reflects the table 5 conditions only Use figures and wording from 6.2 of 60664-1 and define appropriate values for “X” applicable for the tables (depending on the pollution degrees).


DE- 1336 6.3.4.4 Ed The creepage distance can made up be addition Where the creepage distance is made up from the Accepted in principle,

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(e.g. Table 1)

Type of comment


102 of shorter distances (Figure 3, picture (2)) therefore an explanation is meaningful.

addition of shorter distances, for example where a conductive part is interposed, the distance of table 5 has to be accomplished by their sums.

remove reference to Table 5 and replace “has to” with “shall”.

DE-103

1336 6.3.4.4 Figure 3 ed In the upper 6 pictures of Figure 3, the text is bold

change to normal text as in the lower 6 pictures Accepted in principle, figure to be replaced.

DE-104

1336 6.3.4.4 Figure 3 ed give each figure a name/number because in all other figures the sub figures are named/numbered

give the sub figures the name: e.g. Figure 3a; Figure 3b; …

Not accepted, unless subfigures are individually referenced they cannot be numbered.

DE-105

1345 -1355

6.3.4.5 Ed The proposal from Task group “conformal coating” as agreed by the MT has been taken only partly.

Please use the proposed text from the TG as follows to replace lines 1345 to 1355: A conformal coating shall seal the path between the conductors in question against the ingress of moisture and pollution, and shall give an effective lasting unbroken seal. It shall adhere to the conductive parts and to the insulating material. The application of the coating together with a subsequent inspection shall ensure that the conformal coating is complete and homogeneous. For separation distances on a printed circuit board, a solder mask that meets the requirements of a coating Type 1 or Type 2 in accordance with IEC 60664-3 is considered as conformal coating. The manufacturer shall provide evidence of compliance with these requirements.

Accepted in principle, also see US-044.

DE-106

1347 1348

6.3.4.5 1st para, 3rd sentence

Ed The sentence seems to be misplaced here. It makes only sense in conjunction with the 2nd sentence of the 2nd para

Consider to move the sentence to become the 1st sentence of the 2nd para 1st para.

Not accepted. Because of DE-105

US-044

1349 6.3.4.5 Par 1 te Throughout this section, we state that inspection is required, if applicable, except here in this sentence where it appears mandatory 100% of the time. There is no leniency for batch inspection, etc. Recommend aligning this statement with the rest of the statements contained in this section.

Change to “…subsequent inspection, if applicable, shall ensure that…”

Accepted

DE-107

1352 6.3.4.5 2nd para, 2nd sentence

Ed This sentence seem misplaced in between requirements concerning solder masks. Furthermore: Do we still need this sentence after the last sentence was added to the 1st para? The initial intention to modify this clause was to open it in order to allow state of the art coating

Consider to move the sentence to become the 2nd sentence of the 2nd para or if it can be deleted. Why was the proposal of NL09 ignored

Not accepted. Because of DE-105

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methods (see NL09 of 31G/230A/INF).

DE-108

1358 to 1360

6.3.4.5 Note 2 Ed This Note would better fit below the 1st para to explain the added sentence (line 1348, 1349

Consider to move the note up to below 1st para Accepted in principle. Move the Note between para 2 and 3 (after application of DE-105)

AU-26

1368 6.3.4.5 4 ed Reword for clarity Modify the text: Where bare conductors or conductive parts emerge from the coating the comparative tracking index (CTI) of the coating shall comply with column 7 of Table 5, Table 6 or Table 7. in column 7 of Table 5 or column 7 of Table 6 or column 7 of Table 7 shall apply the coating.

Accepted in principle, also reworded by TG.

DE-109

1369 6.3.4.5 4th para Ed In clauses before, the column was not repeated for all Tables if all used the identical column.

Delete the repeated “column 7 of” for Table 6 and Table 7

Accepted

GB-098

1369-1370

6.3.4.5 ed Unsure of meaning. Does it mean that the CTI of the coating shall apply?

Add “to” to the start of line 1370. Not accepted as text changed, see AU-26

US-045

1369 6.3.4.5 Par 4 ed Missing the word “to” Change to: column 7 of Table 7 shall apply to the coating

Not accepted as text changed, see AU-26

DE-110

1370 6.3.4.5 Last para Ed A “to” is missing Where bare … shall apply to the CTI of coating. Not accepted, text changed, see AU-26

GB-099

1374 6.3.5 te It is not clear whether or not composite separations may apply to Table 7 (Ed.6 was equally unclear). Table 6 includes Cat III whereas Table 7 does not: it also has larger separations so it seems appropriate to allow composite separations with Table 7.

Add “or Table 7” after “Table 5” (two places) Accepted in principle, see US-046

US-046

1374 6.3.5 ed If composite separation are allowable for Table 6 and 7, the clause should not be specific to Table 5.

Add Table 6 and 7 to line 1374 and 1378. Accepted in principle. The MT agreed that there should be some lower limit to distances which are acceptable and this was set at 0,20 mm based on the lowest Annex F spacing.

GB-100

1377 6.3.5 ed Use of imperative is not consistent Replace “convert all separations” to “all separations shall be converted”

Accepted

GB- 1380 6.3.5 ed The indented paragraphs would be better as Make the last two criteria bullet pointed items: Accepted

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101 bullet points • For Level of Protection "ia" and "ib", a percentage less than 33,3% shall be ignored. For the separation to be infallible, the sum shall be at least 100%.

• For Level of Protection "ic", the sum shall be at least 100% if it impairs intrinsic safety.

GB-102

1380 - 1382

6.3.5 ed Space missing before “%” in three places Add hard space. (three places) Accepted

US-047

1382 6.3.5 1 ed Reword for clarity For Level of Protection "ic", the sum shall be at least 100% if it a failure of the separation impairs intrinsic safety.

Accepted

DE-111

1385 1388

6.3.6 Ed The correct term for creepage and clearance should be used.

Where clearances and creepage distances affect the …

Accepted

DE-112

1399 6.3.6 Te The whole component is deemed to be conductive according to the para added to 6.3.1 in lines 1154 to 1159. A reference to 6.3.1 or moving the para from 6.3.1 to 6.3.6 would make sense

Consider to either move the para or and add a reference back to 6.3.1.

Accepted in principle, incorporated 1) into body text and deleted 2) as it is unnecessary.

US-048

1402 6.3.6 Figure 4a ed The arrows in this figure imply a specific spacing as shown in figures 4b and 4c. In the case of figure 4a, they are used in indicate a region of the figure.

Delete the dimension lines in figure 4a. Not accepted, the key does not describe them as dimensions.

DE-113

1403 6.3.6 ed Example unnecessary – or lead to misinterpretation

“ *The free surface of a PCBA which is coated only partial (e.g. PCBA which is coated on one side only)”

Not accepted, the MT found that the change did not clarify the example.

DE-114

1403 -1413

6.3.6 Figures Ed The rules of ISO/IEC directive 2 are not met. See comment and proposal made to figures 1 Not accepted, proposed change was not understood.

DE-115

1405 6.3.6 Figure 4b) Ed The title of this subfigure is incomplete PCBA with soldered leads protruding the coating Accepted in principle, added “through”.

DE-116

1409 6.3.6 Key Ed The Key belongs to all subfigures, as the NOTE. Separate it from Figure 4c and decrease the indentation.

Accepted

DE-117

1410 6.3.6 Key a Ed The correct term is clearance and not “clearance distance”.

Change to: Apply clearance requirements of 6.3.4.1

Accepted

IT-07 1423 6.3.7 ed “ … of sufficient height does not ...” Height, width, length?

“ … of sufficient dimensions does not …” Accepted

DE-118

1426 6.3.7 Ed Clarify partition in earthed metal partition “An earthed metal partition either shall be at least…”

Accepted

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CH-29

1426 6.3.7 te By folding of thin plates rigidity of constructions could be tremendously increased. Compliance with 9.6.3 should be sufficient to justify the construction.

Delete second part of the sentence: A partition either shall be at least 0,45 mm thick, or shall comply with 9.6.3 if of lesser thickness and attached to a rigid, earthed metal portion of the device.

Accepted in part, retained text about attachment to the device.

DE-119

1433 - 1447

6.3.9 te 6.3.9 doesn't specify test voltage requirements between separated intrinsically safe circuits for insulation of internal wiring.

Add the following subclause / title in front of the 1st paragraph: 6.3.9.1 General Add the following subclause / title between the 2nd and 3rd paragraph: 6.3.9.2 Insulation between intrinsically safe and non-intrinsically safe circuits Add the following new subclause, title and paragraph in front of the NOTE in 6.3.9: 6.3.9.3 Insulation between separated intrinsically safe circuits The distance between the conductors of any core of separated intrinsically safe circuits shall be in accordance with column 4 of Table 5 taking into account the requirements of 6.3.5 except when one of the following apply: - the cores of either intrinsically safe circuit are enclosed in an earthed screen complying with 6.4.4, or - the insulation between separated intrinsically safe circuits with a maximum voltage of 90 V (peak value) between the conductors is capable of withstanding an r.m.s. a.c. test voltage of 1 000 V (or 500 V core to insulation) when tested in accordance with 9.3.

Accepted

GB-103

1439 6.3.9 3rd Paragraph

te Reference to Table 6 and 7 missing? Change to “…shall be in accordance with column 4 of Table 5, Table 6 or Table 7…”

Not accepted, Tables 6 and 7 are only applicable to PCBs, not to wiring.

DE-120

1439 6.3.9 3rd para Ed If the device is specified for pollution degree 2, the insulation of internal wiring can also be designed according to Table 6 or Table 7 as applicable.

…shall be in accordance with column 4 of Table 5 or column 2 of Table 6 or column 5 of Table 7 as applicable, taking into account…

Not accepted, Tables 6 and 7 are only applicable to PCBs, not to wiring.

DE-121

1440 6.3.9 Ed “except when one of the following apply” seems not correct: “one” is singular, “apply” is plural

Change to “applies” Accepted

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DE-122

1443 6.3.9 3rd para, 2nd dash

te 6.3.9 doesn't specify a voltage limit for the 2nd exception when tested with a test voltage of 2000V. This test voltage shall apply only for peak voltage up to 375V between the conductors. Suggestion: add the maximum voltage 375 V.

Change 3rd paragraph 2nd exception to: - in Levels of Protection "ib" and “ic” electrical apparatus with a maximum voltage of 375 V (peak value) between the conductors, the insulation of the intrinsically safe cores is capable of withstanding an r.m.s. a.c. test voltage of 2 000 V when tested in accordance with 9.3.

Accepted

DE-123

1448 6.3 ed The requirements for separation between an intrinsically safe circuit and earth is quite complex. For better understanding a flow chart should be added.

Add the following new subclause, title and paragraph with figure 5 in front of 6.4 6.3.10 Separation between intrinsically safe circuits and earth Figure 5 shows the separation requirements between an intrinsically safe circuit and earth and shall be used for safety analysis on the separation of an intrinsically safe circuit to earth.

Does the type of protectiondepend on the separation

to earthed parts

Safety analysis on the separation of an intrinsically safe circuit to earth

YES

Separation distances between the intrinsically safe circuit and earth in

accordance with Table 5, 6 and 7 apply

The intrinsically safe circuitwithstands a dielectric strength test

with >500 VAC

Separation distances between the intrinsically safe circuit and earth

shall not apply

Equipment marked with symbol “X“Notification in the documentation regarding

the correct installation

NO

YES

The intrinsically safe circuit is considerednot separated from earth

NO

Figure 5 EXAMPLE The type of protection depends on the separation to earthed parts if a shunt safety assembly fails to an open-circuit condition by short-circuits between the circuit and the earthed part.

Not accepted, the figure as presented does not cover all scenarios and duplicates existing requirements. There are no differences in interpretation of these requirements which would necessitate further explanatory material.

PCB-TG

6.4.1 1 Te The TG revisited the requirements for countable fault connections as found in 6.4.1 of the latest draft. The historical approach to PCB connections that are relied on for intrinsic safety is as follows:

1. Meet the requirements for infallible tracks (eg. 1 x 2mm track or 2 x 1mm tracks)

2. Use multiple independent tracks that do not meet the infallibility requirements but

Decide if there is consensus to add a basic requirement to 6.4.1 that all conductors and connections relied upon for intrinsic safety must be adequately rated for the maximum current.

Revised 6.4.1 (now 6.5.1) to require that the failure of internal connections and connectors may be considered a countable fault only if they are rated using available data. The reference to 5.4.4 was removed to isolate the thermal requirements found in 5.4 from the

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require a countable fault to open circuit. In the case of 2 above, there have historically been no dimensional or rating requirements applied to the tracks. Essentially, any circuit board track regardless of fault current or track dimension required a countable fault to open circuit. This is commonly used to create ‘infallible’ connections using three independent ‘thin’ tracks within ‘ia’ apparatus. Some designers and certifiers assumed that even these countable fault tracks must meet the thermal requirements of 5.4.4 or at least be adequately rated to be treated as countable open circuit faults but the current and previous versions of 60079-11 did not explicitly state this. Adding a requirement for tracks not meeting the infallibility requirements to be ‘adequately rated’ in order to be countable open circuit faults could be seen as a major technical deviation in some cases leading to recertification of equipment.

connection requirements of 6.5.1. This was done to enhance clarity and to address the need for connection requirements in associated apparatus that would not be subject to the requirements of 5.4.4.

CH-30

1449 6.4.1 te MT 60079-11 has seen the necessity to point out the current carrying capacitance of conductors, connectors or tracks, including its connections. The circumstance that the continuous operating temperature of the insulation material and thermal ignition compliance needs to be respected was considered to be not sufficient. The way 6.4.1 is written does not reflect the intention of the committee, except by indirect statements which are difficult to be understood.. By addressing the current carrying capacity in 6.4.1 the requirement is stated for all subclauses within 6.4.

Change to Where conductors, connectors or printed circuit board tracks, including their connections affect intrinsic safety of the apparatus, they should be capable to carry the current to which they could be continuously subjected at their place of installation after the application of faults as required by 5.2. Failure to open-circuit of any such conductor, connector or printed circuit board track, including its connections, which does not comply with 6.4.2 shall be considered a countable fault in accordance with 5.2 The assessment of internal connections or connectors shall be done by using available data, by using the thermal ignition compliance in 5.4 (except the 10 mm exception in 5.4.4) or by actual measurement. EXAMPLE Examples of available data include manufacturer data sheets and standards on connection, connector or printed circuit boards.

Accepted in principle. Revised 6.4.1 (now 6.5.1) to require that the failure of internal connections and connectors may be considered a countable fault only if they are rated using available data. The reference to 5.4.4 was removed to isolate the thermal requirements found in 5.4 from the connection requirements of 6.5.1. This was done to enhance clarity and to address the need for connection requirements in associated apparatus that would not be subject to the requirements of 5.4.4.

GB-104

1450 6.4.1 1st Paragraph

ed “tracks”…should be singular. Change: “tracks” to “track” Accepted

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DE-124

1450 6.4.1 1st para Ed The plural of “printed circuit board tracks” should be singular.

Failure to open-circuit of any conductor, connector or printed circuit board track, including…

Accepted

DE-125

1452 6.4.1 Te Open-circuit-failure of a conductor is countable, “if rated for the maximum current or thermally rated in accordance with 5.4” What, if this ratings are not fulfilled? Is the failure non-countable in this case? Is the open-circuit-failure assumed for ic then? Thermal rating of 5.4 is originally for temperature classification. The desired temperature class has nothing to do with the permissible wire temperature. For associated apparatus outside explosive areas, there is not even a temperature class.

Include: If these requirements are not fulfilled, the open-circuit-failure is non-countable. For ic, if these requirements are not fulfilled, it cannot be relied on the connection. Delete or explain

Accepted in principle. Revised 6.4.1 (now 6.5.1) to require that the failure of internal connections and connectors may be considered a countable fault only if they are rated using available data. The reference to 5.4.4 was removed to isolate the thermal requirements found in 5.4 from the connection requirements of 6.5.1. This was done to enhance clarity and to address the need for connection requirements in associated apparatus that would not be subject to the requirements of 5.4.4.

US-050

1452 6.4.1 ge Is there a test that could be specified for determining if a connection is rated for maximum current? Perhaps the test of 9.13 could be used, but modified to use the maximum continuous current instead of 1.5 times. The title and content of 9.13 would need to be modified.

Consider if the test of 9.13 with maximum continuous current would be a sufficient test for demonstrating that the connection in question is rated for the maximum current.

Accepted in principle. The revised text of 6.4.1 (now 6.5.1) does not exclude applying a test similar to the one found in 9.13 as the results of this test would be considered “available data”.

US-051

1453 6.4.1 ge A remark for tracks considered countable open circuit faults (similar to the remark in Table 8) is needed.

Add: ‘All printed circuit board tracks, regardless of length, that are considered countable open circuit faults shall meet the thermal requirements found in 5.4.4. This includes printed circuit board tracks in associated apparatus. In the case of associated apparatus, a temperature code rating of T4 shall be assumed in determining the track width and maximum permissible current.’

Accepted in principle. Revised 6.4.1 (now 6.5.1) to require that the failure of internal connections and connectors may be considered a countable fault only if they are rated using available data. The reference to 5.4.4 was removed to isolate the thermal requirements found in 5.4 from the connection requirements of

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6.5.1. This was done to enhance clarity and to address the need for connection requirements in associated apparatus that would not be subject to the requirements of 5.4.4.

DE-126

1455 ff

6.4.1 Te “The initial break is one countable fault…” This seems not to fit with the sentence before. In the sentence before, the fault is only countable under certain conditions (otherwise non-countable??)

Change line 1454 to: “If under the conditions above the connection is free to move after failure to open circuit, a short circuit …”

Not accepted. The first paragraph makes clear the requirements for countability. It is not necessary to cover this again in paragraph 2.

GB-105

1459 6.4.2.1 ed “the connection” requires assuming “infallible connection” from the subclause title one level up which is best avoided.

Modify: For levels of protection Levels of Protection “ia” and “ib”, the connections shall be made via connectors, wires, printed circuit boards or other connections complying with 6.4.2.2, 6.4.2.3, 6.4.2.4 and 6.4.2.5 as applicable, and such connections shall be that are protected by an enclosure of at least IP20, including when exposing connection facilities, shall be considered infallible against failure to open circuit.

Accepted

CH-31

1464 6.4.2.1 te It seems to be a wrong relation to exclude a clause in one of its subclauses. It seems to be consistent move this statement to 6.4.1 Add also 6.4.3 and 6.4.4 as exclusions for “ic”.

Move to 6.4.1 For Level of Protection “ic”, the requirements of 6.4.2, 6.4.3 and 6.4.4 do not apply.

Accepted, also deleted requirements for “ic” in 6.4.2.2 and 6.4.2.3 to make this a consistent statement.

DE-127

1467 ff

6.4.2.2 Te There are no requirements on the diameter/cross-section of the conductors.

Include: Each conductor shall be able to carry the complete current.

Accepted in principle. Revised 6.4.2.2 to: “Connectors shall be considered infallible if the connection comprises at least three independent connecting elements for "ia" circuits and at least two for "ib" circuits (see Figure 5). These elements shall be connected in parallel. Where the connector can be removed at an angle, one connection shall be present at, or near to, each

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(e.g. Table 1)

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end of the connector. For Level of Protection “ic” circuits, a single connecting element is sufficient. Each conductor shall be rated to carry the complete current. Where complete disconnection of a connector needs to be assumed, the circuits shall remain intrinsically safe.”

DE-128

1467 -1469

6.4.2.2 ed Multiple use of the word connector, connection, connecting.

Connectors shall be considered infallible if the connection compromises at least three independent connecting elements for "ia" circuits and at least two for "ib" circuits (see Figure 5) ...

Accepted

DE-129

1467 6.4.2.2 Figure 5a ed same font size as Figure 5 reduce font size of Figure 5a by one Accepted

GB-106

1471 6.4.2.2 1st para te Clarify that each element needs to be rated for the fault current as failure of each element is not described as a countable fault.

Add to end of paragraph: “Each element shall be rated to carry that current that the whole connector carries under the conditions specified in 5.2.”

Accepted in principle. See DE-127.

GB-107

1472 6.4.2.2 2nd para ed Missing “Levels of Protection” is not consistent with the rest of the text.

Add “Level of Protection” Accepted

CH-32

1472 6.4.2.2 te Make the text in line 1472 a note. The text should not be normative, because 6.4.2.2 is excluded for “ic” in line 1464.

Note: For “ic” circuits a single connecting element is sufficient.

Accepted in principle, text deleted.

DE-130

1476 1478

6.4.2.2 Figures Ed Use the correct subfigure titles See comments to figure 1 cl.6.2.1 Not accepted, DIR 2 requires subfigures to be numbered.

DE-131

1478 6.4.2.2 Figure 5b ed same font size as Figure 5 reduce font size of Figure 5b by one Accepted

AU-27

1482 6.4.2.3 1 te Ensure that each of the redundant wires is appropriately rated for the full current load.

Modify the text: a) where two wires are in parallel and individually rated to 5.4.3, or

Accepted in principle. Revised 6.5.2.3: Wiring is considered to make an infallible connection: a) where two wires are in parallel and individually rated using

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available data, or b) where a single wire has a diameter of at least 0,5 mm and has an unsupported length of less than 50 mm or is mechanically secured adjacent to its point of connection, or c) where a single wire is of stranded or flexible ribbon type construction has a cross-sectional area of at least 0,125 mm2 (0,4 mm diameter), is not flexed in service and is either less than 50 mm long or is secured adjacent to its point of connection.

US-049

1483 1485

6.4.2.3 ge The wire diameter and ribbon cable cross-sectional area do not specify if both the conductor and insulator contribute to the diameter/cross-sectional area, or if only the conductor(s) should be considered.

Clarify if insulation should be included in the diameter/cross-sectional area determination.

Accepted in principle, add “conductor” before diameter in b) and cross-sectional area in c).

DE-132

1490 6.4.2.4 Te For infallible traces on PCBs, there may be connections to parts that need to be infallible, but the pad of the part would not support the 2mm wide or 2 track termination. Add details on how to handle this. Allow for track widths to be minimized to within pad size some distance from the pad to allow for proper termination of track into part.

Perhaps add a NOTE to the table to allow for traces to neck down to pad width within 2mm of the pad edge distance. Perhaps add some images to clarify.

Accepted in principle. No change required as other alternatives are already available (eg. 2 x 1 mm or 3 independent tracks).

US-052

1492 6.4.2.4 Table 8 ge The asterisk (*) and double asterisk (**) text found in Table 8 may be better suited as paragraphs in 6.4.2.4, rather than in the table itself. The asterisks can then be removed throughout Table 8.

Move this text outside (below) Table 8: Single printed circuit board tracks and vias that do not meet these the requirements of Table 8 shall be considered infallible if they have a minimum width or circumference of 1 mm and comply with the test requirements of 9.13. Via circumference is measured at the midpoint of the hole plating.

Accepted in principle. Moved the notes to body text to improve clarity.

CH- 1492 6.4.2.4 te We have understood the resume of the Task Please consider the following proposal: Accepted.

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33 Group pc in the way, that the information provided by the IPC standards provide sufficient information to judge the current carrying capacity of printed circuit board tracks. Wouldn’t it be possible to allow this assessment printed circuit board tracks defined in 6.4.2.4?

*Single printed circuit board tracks and vias that do not meet these requirements shall be considered infallible if they have a minimum width or circumference of 1 mm and comply with the test requirements of 9.13, except when available data can make the test redundant. .

Alternative to the test of 9.13 added along with relevant IPC references.

GB-108

1492 6.4.2.4 Table 8 te Typically, base copper thickness for standard PCBs is 35µm. For outer tracks, this may reduce below 30µm but the PCB manufacturer can be made to minimum 30um with plating to meet the requirements. Starting from 35µm base copper, internal tracks may be as low as 24µm and there is no chance to increase with plating. In practice, the next level of base copper thickness (typically 70µm) would be needed to ensure the 30µm minimum. The table doesn’t distinguish between external and internal tracks so with standard PCBs (35µm base copper) internal infallible tracks would usually need to be tested in accordance with 9.13.

Consider allowing 24µm minimum thickness for infallible internal tracks.

Accepted. This is allowed if the tracks are at least 1mm in width and it can be shown through test (9.13) or the use of available data that and are capable of carrying maximum current.

GB-109

1492 6.4.2.4 Table 8 ed The remarks column contains normative text which has no precedent under DIR-2

Move text of remark to below the table and delete “Remarks” column.

Accepted

DE-133

1492 6.4.2.4 Table 8 ge According IPC 6012B for inner layers final minimum copper thickness is 24.9 µm when starting from nominal 33µm base material. (For outer layers final thickness is 33.4 µm when starting with 17 µm nominal base material).

Require 30 µm for outer layers only and allow 24µm for inner layers to meet the requirements for infallible tracks.

Accepted in principle. This is allowed if the tracks are at least 1mm in width and it can be shown through test (9.13) or the use of available data that and are capable of carrying maximum current.

DE-134

1492 6.4.2.4 Table 8 Ed For vias it is not clear how 5.4.4 should be applied. Shall the circumference be used as the virtual track width in table 3? Because pcb manufacturers can only guarantee plating thickness in vias of 20µm a factor or a value for the circumference of infallible vias with a minimum of 18µm plating would more practical than the 2mm at 30 µm.

Make clear that in 5.4.4 the circumference of a via is used as the Track width Specify a circumference value for an infallible via at 18µm plating.

Accept in principle. Thinner plating is allowed if the tracks are at least 1mm in width and it can be shown through test (9.13) or the use of available data that and are capable of carrying maximum current. The Table heading already makes it clear that via circumference is analogous

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to track width. Clarified this in the body text.

US-053

1492 6.4.2.4 Table 8 Remarks

ge It is not evident that the requirements of Table 8 are applicable only to the exterior layers of printed circuit boards. The constructional requirements and test of 9.13 seem applicable both to exterior and inner layers, but the thermal requirements of 5.4.4 should not apply to inner layers.

Replace the text with ‘All printed circuit board tracks that come into contact with explosive atmospheres, regardless of length, that are relied on for infallible connections shall meet the thermal requirements found in 5.4.4.’

Accept in principle. This paragraph has been deleted as it is no longer needed with the re-structuring of this section. The general requirements of 6.4.1 make it clear that all circuit board tracks on which intrinsic safety depends must be adequately rated and thermally rated to 5.4.

DE-135

1500 -1501

6.4.2.5 c) Te Most components manufactures do only specify pad size. Meeting this sizes does not provide any information about the quality of the soldering joint as there are a lot more parameters to observe. E.g. Reflow or wave soldering, amount of solder etc. There are other standards where the solder quality is described. E.g IEC 61191-2 or IPC-A-610.

Change to “where there is a soldered joint of a surface mount component in accordance with IEC 61191-2 class 2 or IPC-A-610 or similar.”

Accept in principle. Added these references to the existing “manufacturer’s recommendations”.

DE-136

1513 6.4.4 1st para Ed Change the plural to singular …, any conductor, connector, and printed ciruit board track used…

Accepted

DE-137

1516 6.4.4 2nd para Ed Change the plural to singular …area of any conductor and connector used… Accepted

GB-110

1516 - 1519

6.4.4 2nd para te The requirement to be able to carry current should be the case for all infallible connections, not just earth connections, but with the exception of PCBs where current rating is not considered.

Add “with the exception of printed circuit board tracks ” before “the cross-sectional area”. Move paragraph to end of 6.4.2.1.

Not accepted. The resolution of this comment depends on changes to 6.4.1 as to whether countable fault connections must be ‘adequately rated’. While it is true that all connections relied on for intrinsic safety should be adequately rated, this situation is already covered in the existing text of 6.4.2 and its sub-sections. Moving this text to 6.4.2.1 would be confusing as not

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just infallible connections are required to be adequately rated (for example, those not considered infallible but subject to countable fault).

DE-138

1523 6.5.1 a) Ed Use the plural for atmosphere Exclusion of explosive atmospheres Accepted

AU-28

1529 6.5.1 1 te Add detail that encapsulation may be used to form part of the enclosure and ingress protection rating

Modify the text: f) Forming part of the enclosure and ingress protection rating.

Not accepted. The existing text does not exclude this, but there are no additional requirement that need to be applied over and above those stated for enclosures in the rest of the document.

US-054

1529 6.5.1 e) te The use of encapsulation to dissipate heat is not necessarily specific to protective components. Item e) along with 6.5.6 should be more generic.

e) Establishing the rating of protective components or reducing the surface temperature of components. 6.5.6 Encapsulation used to enhance the rating of protective reduce surface temperature of components When the compound is being used to enhance the rating of protective reduce the surface temperature of components the properties, design and arrangement of the compound shall reduce the maximum surface temperature of the component to the desired value and there shall be no free space.

Not accepted. Reducing the temperature to protect against thermal ignition using encapsulation is listed in item a) ii). Limiting the temperature for operational reasons not related to intrinsic safety (e.g. non-safety related) are outside the scope of this standard.

DE-139

1531 6.5.1 2nd para Ed Comma missing after pouring …applied by pouring, the minimum thickness… Accepted

US-055

1534 6.5.1 4,5 ed/te Delete paragraph 4 (starting at line 1538) as the it is poorly worded and the requirements are covered elsewhere. Reword the lead sentence of paragraph 5 for clarity. Move item c) as a new paragraph as this is a generic requirement not directly applicable to the potting compound.

For intrinsically safe apparatus, all circuits connected to the encapsulated conductive parts, components or bare parts protruding from the compound shall be intrinsically safe. The possibility of spark ignition inside shall not be considered if the encapsulation complies with 6.5.2.1. For associated apparatus located within a hazardous area circuits connected to the

Accept in part. Associated apparatus would not be covered if the paragraph is deleted as suggested. Modify in accordance with the suggestion CH-34.

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encapsulated conductive parts, components or bare parts protruding from the compound that are not intrinsically safe, they shall be protected by another Type of Protection listed in IEC 60079-0. Where encapsulation is used, the compound shall comply with the following and where appropriate to any potting box or parts of an enclosure used in the encapsulation process: If intrinsic safety relies on one or more protective devices to limit the maximum temperature of the encapsulating compound, the protective devices shall be provided either external to the equipment or directly integrated into the equipment. The following additional requirements apply; – The protective devices shall be non-resettable. – For Level of Protection “ia” complying with the IEC 60127 series, IEC 60691or ANSI/UL 248 series, only one device is necessary, otherwise three are required. – For Level of Protection “ib” complying with the IEC 60127 series or IEC 60691 or ANSI/UL 248 series, only one device is necessary, otherwise two are required. The encapsulating compound and, where applicable, any potting box or part of an enclosure shall comply with the following: … [move item c) (above)]

DE-140

1535 6.5.1 4th para Ed The term “bare parts” is sometimes used as “bare parts” and sometimes as “bare conductive parts” throughout the standard. In all cases the concern is about conductive parts.

Harmonize this term in the standard. Proposal: “bare conductive part”

Accepted

DE-141

1538 , 1540

6.5.1 2nd para Ed In 1538 a comma is missing between “area” and “circuit” and “they” in line 1540 is superfluous.

Correct wording Accepted

CH-34

1538 - 1541

6.5.1 te By adding the wording “For associated apparatus located within a hazardous area” compared to the text of the 6th edition a limitation is introduced which seems to create more difficulty in understanding. The requirement does not seem to apply to associated apparatus only, but also to ports for

If circuits connected to the encapsulated conductive parts and/or components and/or bare parts protruding from the compound are not intrinsically safe, they shall be protected by another type of protection listed in IEC 60079-0.

Accept in Principle. Modify as follows; “For intrinsically safe apparatus, all circuits connected to the encapsulated conductive parts, components or bare

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maintenance, repair or overhaul of intrinsically safe apparatus. It seems to be preferable to leave the text as it is in the 6th edition.

parts protruding from the compound shall be either intrinsically safe or protected by another Type of Protection listed in IEC 60079-0. The possibility of spark ignition inside shall not be considered if the encapsulation complies with 6.5.2.1.”

AU-29

1538 6.5.1 5 Te This paragraph doesn’t seem to be necessary. According to the scope, associated apparatus located in the hazardous area shall be protected by another Type of Protection.

Remove the text: For associated apparatus located within a hazardous area circuits connected to the encapsulated conductive parts, components or bare parts protruding from the compound that are not intrinsically safe, they shall be protected by another Type of Protection listed in IEC 60079-0”

See CH-34

DE-142

1538 -1541

6.5.1 5th para Ed Delete this para, because it is not a special requirement for apparatus, where encapsulation is used but for all associated apparatus to be used in hazardous areas.

Delete para, but check if the information is still given elsewhere.

See CH-34

DE-143

1542 ff

6.5.1 6th para Ed The sentence is difficult to read: Change to: Where encapsulation is used, the following applies to the compound and where appropriate to the potting box or parts of enclosure used in the encapsulation process

Accept in principle. See US-55. Change to; “The encapsulating compound and, where applicable, any potting box or part of an enclosure shall comply with the following:”

AU-33

1544 6.5.1 a)-i) Ed This is the second ‘lettered’ list in clause 6.5.1, which makes referencing the dot points difficult.

Change the second list to a numbered list. Accepted in part, first bullet points changed to numbers.

AU-30

1548 6.5.1 b) te Service temperature does not take into account malfunctions or faults. Depending on the compound type and thermal conductivity components after the application of faults can generate point sources of heat locally exceeding the compounds COT. The COT of the surface of the compound may not be exceeded but the point source heating can lead to cracking due to pressure exerted from the localised

Modify the text: For Levels of Protection “ia” and “ib” temperatures higher than the compound’s COT rating are permitted under the fault conditions specified in Clause 5 provided that: - the volume and thickness of the compound can withstand the maximum energy dissipated under fault at the maximum ambient temperature; and,

Accept in principle. During discussions at the MT60079-11 meeting in Split, the consensus was that the applied temperature should be the ‘service temperature but with faults applied to the

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thermal expansion of the compound. Testing the compound to the service temperature is not onerous enough for the level of protection afforded by ia and ib in which countable and non-countable faults could lead to greater power dissipation within the compound. Note that the requirement proposed here and the requirement in the CD both suggest a test. AU may propose a formal test in future.

- there is no visible damage to the compound that could impair the intrinsic safety, such as cracks in the compound, exposure of encapsulated parts, flaking, impermissible shrinkage, swelling, decomposition, softening or evidence of overheating that would adversely affect the protection;

circuit in accordance 5.1’ Change to “– The volume and thickness of the compound can withstand the maximum energy dissipated at the maximum service temperature except that the faults in Clause 5 are also considered;”

DE-144

1548 6.5.1 6th para, b) Ed “temperatures higher than the compound’s COT rating” This formulation has given a deviation to our test center at the programs of proficiency testing for IECEx.

Paragraph b) completely delete or specify a concrete difference until an exceedance is tolerable, eg <10 K

Not accepted. The key requirement is that the encapsulation is not damaged, not that there is an arbitrary over-temperature.

GB-111

1549 6.5.1 b) ed Fault conditions are in 5.2. This is applicable in normal operation.as well as fault conditions.

Modify “under the fault conditions specified in Clause 55.2

Accepted

CH-35

1554 - 1563

6.5.1 c) te The intended requirement in the context of encapsulation is not obvious. It seems to describe an approach on thermal ignition compliance and power rating of components in a more general way. The requirements do not seem to be properly located. Component requirements including their failure modes and their conditions of infallibility should be located in clause 7. Resettable and non-resettable protective devices should be suitable and their conditions of use should be described in clause 7.

Delete text from 6.5.1 Not accepted. There is no proposal for the modification to Clause 7 for the requirements of resettable fuses.

DE-145

1554 to 1562

6.5.1 6th para, c) Ed / te c) seems to be totally misplaced in the list of items the compound shall comply with With the addition of c) a significant technical change increasing the requirements for encapsulation above the level of “m” is established, requiring non-resettable protective devices. The first dash requiring non-resettable devices for all levels contradicts to the following two dashes. Following the “m” route the use of a single device

Discuss and consider if increasing the requirement is intended or if three resettable devices are acceptable for “ia” (and two for “ib”) If agreed on acceptance of three resettable ones for “ia” let c) become a separate para and modify wording: Where the limitation of component temperatures under encapsulation relies on a protective device the following applies The protective devices shall either be external to

Agree in Part Move item c) (See also US-55) Changes relating to resettable fuses, not accepted. Requirements relating to the use of resettable fuses have not been developed by the MT

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complying with IEC 60127, IEC 60691 or ANSI/UL 248 shall be allowed for all levels. It should be viable to allow resettable devices under the provision to have three for “ia” and two for “ib”. (“mb also allows the use of two resettable devices.

or be an integral part of the encapsulated area as appropriate A single non resettable device complying with the IEC 60127 series, IEC 60691 or ANSI/UL 248 series is considered sufficient for all levels of intrinsic safety. Alternatively for level “ia” three devices including resettable devices are required Alternatively for level “ib” two devices including resettable devices are required Alternatively for level “ic” a single device including resettable device is required

DE-146

1556 6.5.1 Ed Behind apply, there should be a “:” instead of a semicolon because an enumeration follows

Replace semicolon by “:” Accepted

GB-112

1557 6.5.1 c) te The requirement “protective devices shall be non-resettable.” is new and would be in conflict with the current requirements. Why is it required for the protective device to be non-resettable? Has this requirement been added for PTC fuses being used to protect the compound? What if the protection device or circuit is electronic and triplicate?

Change text: “If the protective devices are single thermal cutoff devices then they shall be of a non-resettable type.”

Not accepted. The requirements for resettable fuses are not defined

AU-31

1557 6.5.1 c) First dot point

Te The present text “The protective devices shall be non-resettable”, when read with the subsequent dot point “…otherwise three are required” is unclear. If there are three devices, and these are according to Clause 7, then they can be resettable (For example, resistors, transistors, PTC’s, can all be used provided the adequate fault count is used).

Change dot point 1 to: If the protective device is resettable, then failure to operate shall be considered a countable fault.

Not accepted. The requirements for resettable fuses are not defined

AU-32

1558 6.5.1 c) Dot points 2 & 3

Ed Wordsmithing Change to: – For Level of Protection “ia”, a single device complying with the IEC 60127 series, IEC 60691 or ANSI/UL 248 series is acceptable, otherwise three are required. – For Level of Protection “ib”, a single device complying with the IEC 60127 series or IEC 60691 or ANSI/UL 248 series is acceptable, otherwise two are required.

Accept in principle. Replace first “or” of the second bullet point so it is consistent with the first.

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DE-147

1573 6.5.1 g) Te Why is the requirement “free of voids” added, This was not in 6.6.1 of 6th Ed. and with IEC 60079-18:2014 this is not required for “m”, but reduced to define how voids are avoided in the encapsulation process.

Modify g) to line-up with 60079-18: “g) measures to prevent voids in the compound shall be defined for the encapsulation process.”

Accept

FR-13

1575 6.5.1 5th par, h) ed Free spaces requirements are not in 6.5.6, but in 6.5.7.

Modify the reference to 6.5.7

Accept

DE-148

1576 -1577

6.5.1 i) Ed i) is also part of clause 6.6.3: So delete here. Delete i) Accept

IT-08 1583 6.5.2.1 Figure 6 ed Figure 6 appears twice. Delete one Accepted

DE-149

1583 6.5.2.1 Figure Ed Hanging figure Delete figure, because it is repeated later as figure 6

Accepted

GB-113

1583 6.5.2.1 1st para ed Figure 6 drawing appears twice. Delete first occurrence. Move Figure 6 to below 1st paragraph.

Accepted

AU-34

1583 6.5.2.1 1 ed Figure 6 is incorrectly duplicated in line with text Delete duplicated figure on line 1583 Accepted

US-056

1583 6.5.2.1 Figure ed The figure in this section is identical to Figure 6. Delete the redundant figure. Accepted

FR-14

1583 6.5.2.1 1st ed Figure IEC 1419/06 is duplicated Delete the figure IEC 1419/06 in line 1583 Accepted

DE-150

1585 6.5.2.1 1st para Ed Reference to Figure 8 is wrong Refer to Figure 7 Accepted

GB-114

1585 6.5.2.1 1st para ed Reference should be to Figure 7 (no enclosure), not Figure 8

Change reference from Figure 8 to Figure 7. Accepted

FR-15

1585 6.5.2.1 1st ed Minimum thickness of compound is described in Figure 7, not figure 8

Replace Figure 8 with Figure 7 Accepted

GB-115

1588 6.5.2.1 2nd para te Reference to “Figure 9” should be to Figure 8, and Figure 10 is referenced twice.

Replace “Figure 9, Figure 10 and Figure 10” with “Figure 8 and Figure 10”.

See US -057

DE-151

1588 6.5.2.1 2nd para Ed “Figure 10” duplicate, Figures 8 and 9 also show possible use of metallic enclosures

Change to (See Figure 8, 9 or 10) See US -057

AU-35

1588 6.5.2.1 2 ed Figure 10 is listed twice Modify the text: (see Figure 9, Figure 10 and Figure 10).

Accepted

US-057

1588 6.5.2.1 3 ed Incorrect figure references. (see Figure 98, Figure 109, and Figure 10) Accept NOTE: In the working document these are

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numbered Figures 1 to Figure 11. A check will need to be made to ensure that these are correct when this text is imported in to the draft.

IT-09 1588 6.5.2.1 ed There is some confusion in the text with the Figure numbers.

“..Figure 10..” repeated; no reference to Figure 7. Review properly.

Accepted

FR-16

1588 6.5.2.1 2nd ed Compound in direct contact with enclosure is illustrated in Figure 8 to 10.

Replace “Figure 9, Figure 10 and Figure 10” with “Figure 8, Figure 9 and Figure 10”

See US -057

AU-36

1589 6.5.2.1 4 Te This paragraph specifies a minimum thickness of 1mm for the encapsulating compound. Why is this needed if the encapsulant provides the dielectric strength required and the metallic enclosure excludes the atmosphere? The Figures 8 to 10 also do not indicate any compound thickness requirement between the component and metallic enclosure.

Remove the sentence “the minimum thickness of the encapsulating compound shall be at least half the values shown in column 3 of Table 5, with a minimum of 1 mm”. Change to: Where the encapsulating compound is in direct contact with and adheres to a metallic enclosure, there is no minimum thickness required for the metallic enclosure. If this enclosure also forms the external enclosure of the apparatus, it shall comply with 6.1 (See Figure 10). Note: The requirements 6.3 and 6.8 still apply.

Accept in principle. Replace “still apply” with “remain applicable”. Figure 10 is for Use of compound to provide protection of fuses in an intrinsically safe apparatus. Figure 5 is correct.

GB-116

1589 - 1593

6.5.2.1 4th para te This is a significant departure from Ed. 6 Figure D.1 d) where the encapsulant has no specified thickness. If there is no specified insulation thickness then the metal enclosure should be infallibly connected in such a way as to ensure that a breakdown of the insulation makes the circuit safe: without that, a breakdown of the insulation could leave the metal enclosure at a problematic voltage.

Change paragraph to: Where the encapsulating compound is in direct contact with and adheres to a metallic enclosure then either of the following applies: a) there is no minimum thickness for the

compound where failure of the separation does not impair intrinsic safety, for example, where the enclosure may be at the connected potential, or where the enclosure is infallibly connected to a defined circuit such as earth; or

b) the minimum thickness of the encapsulating compound shall be at least half the values shown in column 3 of Table 5, with a minimum of 1 mm.

There is no minimum thickness required for the metallic enclosure. however iIf this enclosure also forms the external enclosure of the apparatus, it shall also comply with 6.1 (See Figure 10).

See AU-36

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DE-152

1593 6.5.2.1 3rd para Ed Why only referencing to Figure 10? Figures 8 and 9 also show possible use of metallic enclosures

Change to (See Figure 8, 9 or 10) Accept

DE-153

1594 -1595

6.5.2.1 Figure 6 Ed This figure is useless. It shows only two components in a schematic with a surrounding dotted line. It does not show the use of compound to exclude an explosive atmosphere as the figure title suggests.

Delete Figure 6. Accept in Principle. Possibly retain for next CD with note that this will be deleted unless someone really wants to keep it.

DE-154

1601 -1616

6.5.2.1 Figures 8, 9 and 10

Ed The figures are in contradiction to the requirements of 6.5.2.1, 3rd para. In all cases the component(s) inside do not have a defined distance to the inner wall of the metal enclosure. This means that non-IS components or circuitry enclosed can be in direct contact with a bare conductive part (the enclosure), which is exposed to the ambient. If a metal enclosure is used as container for the compound the non-IS circuitry encapsulated (component) must always be in a distance of half the value of the separation distance required in column 3 of table 5, with at least 1 mm from the inner wall of the enclosure.

Delete specification of thickness in the Key of the figures (applies to Figure 7, 11 and 12 as well) to avoid contradiction with the requirements given in the text.

Not accepted The thickness specified in keys is to free surface, not a metallic enclosure. See also AU 036

US-058

1601 6.5.2.1 Figures te Correct the figures in this section to match the requirements found on lines 1591 and 1592. Figure 8: item 2 indicates that there is no specified thickness but this is only true in the case of an insulating enclosure. For the metallic enclosure, the required thickness is ½ of the value found in column 3 of table 5 with a minimum of 1mm. Figures 9 and 10 have this same problem as it depicts an encapsulated component in direct contact with a metal enclosure in violation of the requirements in line 1591/2.

Figure 8: 2 Compound:

- Insulating enclosure: no specified thickness

- Metal enclosure: ½ of the value found in column 3 of Table 5 with a minimum of 1 mm

Figure 9: 4 Metal or insulating enclosure Figure 10: 2 Compound: ½ of the value found in column 3 of Table 5 with a minimum of 1 mm 3 Metal or insulating enclosure

Not accepted Fig 8: There is no specified compound thickness to an adhering metal enclosure (other than as required by separation requirements), Fig 9: The only relevance of the enclosure (so far as encapsulation is concerned) is that the encapsulation adheres to it. That is not affected by the material. Figure 10: If the cover is fixed and s/c between the component and the cover does not impair IS then there would be no thickness requirement for the compound,

FR- 1603 6.5.2.1 Figure 8 te Lines 1589 to 1591 add a thickness requirement Delete “no specified thickness” for the compound See US-058

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17 of ½ of column 3 of table 5, with a minimum of 1mm, for compound in direct contact with and adherent to a metallic enclosure. But Figure 8 deals with “compound – no specified thickness”. This is inconsistent.

in the key of figure 8

DE-155

1630 ff

6.5.2.1 Ed “This sometimes referred to as insert moulding”: Verb is missing

Change to: “This is sometimes referred to as …”

Accepted

DE-156

1638 6.5.2.1 Figure 12 Key

Ed This will only work if the pcba has no through-holes in the enclosed area.

Some requirements about the pcba should be added. E.g. “no through-holes”, “homogenous insulating material of at least 0,5 mm thickness in the area framed by the moulding” etc.

Accept in principle Add to end “with no through holes in relevant area”.

DE-157

1643 6.5.2.1 Figure 12, NOTE 2

Ed There should be a “:” instead of a semicolon behind “are”

Change semicolon into “:” Accepted

BR-05

1650-1651

6.5.2.2 2nd te The clause 5.4 provides the requirements for determination of temperature class, which is not limited to temperature measurement only. Therefore, the determination of the minimum thickness of encapsulation to achieve a temperature class should not be limited to temperature measurement only. This sub-clause should refer to the clause 5.4.

Replace the phrase “by temperature measurement” by “according to the clause 5.4”.

Accept in part. Replace “reduce the maximum surface temperature of the compound to the desired value” (1648) with “ensure compliance with 5.4”. Then delete sentence “The minimum thickness” (1650)

DE-158

1654 6.5.2.2 Figure 13 Ed This figure is useless. It shows only two components in a schematic with a surrounding dotted line. It does not show the use of compound to limit external surface temperature as the figure title suggests.

Delete Figure 13. Accept in Principle. Drawings which show electrical components will be deleted. Those that show the construction of the encapsulated assemblies will be retained,

US-059

1654 6.5.2.2 2 te The figure is an example of encapsulant used to reduce temperature. It would be more clear if only a single component was shown within the encapsulant.

Delete the protective resistor from the figure. See DE-159

DE-159

1659 6.5.3 Figure 14 Ed This figure is useless. It shows only three components in a schematic with a surrounding dotted line. It does not show the use of compound to avoid access to conductive parts as the figure title suggests and has nothing to do

Delete Figure 14 Accept in Principle. See DE -158

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(e.g. Table 1)

Type of comment


with the title of this clause.

DE-160

1660 ff

6.5.3 Te Column 3 applies for casting only. For moulding, column 4 is applicable.

Change to use text of 6.5.4: “The minimum thickness to the free surface when the compound is cast or poured shall be at least half the value given in column 3 of Table 5 with a minimum of 1 mm. The minimum thickness to the free surface when moulded shall be at least the value given in column 4 of Table 5 with a minimum of 0,5 mm.”

Accepted

DE-161

1665 -1666

6.5.4 Figure 15 Ed This figure is useless. It shows only the symbol of a fuse in a schematic with a surrounding dotted line. It does not show the use of compound to provide protection of fuses in an intrinsically safe apparatus as the figure title suggests.

Delete Figure 15 Accept in Principle. See DE -158

DE-162

1672 -1683

6.5.5 Te Why is it necessary to have a minimum thickness of compound to the free surface of 1 mm. For separation distances through compound only the thickness of compound between the potentials to be separated is important. If compound is used like conformal coating, it fulfils its purpose for a proper separation, even if the thickness is less than 0.2 mm. Furthermore the reference to Table 6 or 7 does not make sense, because these tables specify values far below 1mm

Delete the whole clause because this is already given in 6.3.4.2. Delete reference in 6.3.4.2 to 6.5.5 and consider if adding any requirement in 6.3.4.2 is necessary.

Accept in part. The 1 mm was specified in the 6th edition. Conformal coating is applied using spraying, brushing, dipping or selective coating by machine. Potting is applied by pouring the compound in to a defined potting box. The reference to Table 5, 6 or 7 is not applicable as that is the distance between conductive parts whereas the 1 mm is the distance to the free surface. See US-060.

DE-163

1672 ff

6.5.5 Te The whole clause refers to column 3 only. It is hence only valid for casting compound, not for moulding (solid insulation, column 4)

Include considerations for moulding Not accepted. Solid insulation as defined in IEC 60079-0 is “electrical insulation material, which is extruded or moulded, but not poured” so moulding is already covered.

US- 1680 6.5.5 2 ed Reword for clarity. Figure 16 shows the separation of intrinsically safe Accept in Principle.

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(e.g. Table 1)

Type of comment


060 circuits. The marked separation distances are subject to the separation distances found in comply with column 3 of Table 5, Table 6 or Table 7 as appropriate. The minimum thickness to the free surface shall be at least 1 mm.

Change to “Figure 16 shows the separation of intrinsically safe circuits. The marked separation distances comply with 6.3.4.2.”

DE-164

1686 1687

6.5.6 1st para Ed/te It is not clear if the thermal impedance rating or which other rating is improved by the encapsulation. If the thermal impedance is improved, the resulting lower component temperature, but not the surface temperature is the criteria. It is not clear where there shall be no free space. (should be “voids”)

Clarify what is improved and where there is no free space allowed. Possibly add “…there shall be no voids adjacent to the component.

Accept in principle Encapsulation may be used to enhance the rating of protective components e.g. Zener diodes, using an increased thermal conductivity provided that the arrangement can be demonstrated to be suitably effective under the conditions specified in 5.2.

US-061

1687 6.5.6 1 te The free space restriction is not applicable to use of encapsulation for rating of a component. Delete this part of the requirement.

When the compound is being used to enhance the rating of protective components the properties, design and arrangement of the compound shall reduce the maximum surface temperature of the component to the required desired value. and there shall be no free space.

Accept

DE-165

1690 to 1696

6.5.7.1 1st para Ed/te Unclear what is meant by: … provided they comply with the following , as appropriate except for; a ) Fuses, unless they are separately certified as intrinsically safe components b) Components which, under fault conditions specified in Clause 5, would otherwise have damaged the potting compound. Does this say that fuses (requiring encapsulation per 7.10) are not allowed if they have free space?

Make clear what is required and adjust text accordingly. ”Otherwise delete Clause” Possibly change to: “comply with clauses 6.5.7.2 - 6.5.7.4 as appropriate, except for: “potting” is not used elsewhere in -11; delete “potting”

Accepted in principle Change as follows; - Combine 6.5.7.2 & 3 to

single “Volume of free space” subclause starting “For Group I and Group II,…” etc.

- Replace “the following” with “6.5.7.2 and 6.5.7.3” (as re-numbered)

Delete “potting”.

CH-36

1693 6.5.7.1 a) te The part of the sentence describes an exception (fuse) defined by another exception (unless they are separately Ex component certified …).

Please consider a more clean description of the requirements.

Accept in principle Add “Fuses that are not separately Ex Component certified as intrinsically safe”

GB- 1695 6.5.7.1 b) ed It may not require faults to damage the Modify “under the fault conditions specified in Accepted

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117 compound Clause 55.2”

DE-166

1698 6.5.7.2 Ed Behind exceed, there should be a “:” instead of a semicolon

Change semicolon into “:” Accepted

FR-18

1707 6.5.7.4 1st te no minimum thickness of compound around the free space is specified. (IEC 60079-18:2015, table 2 and 3 gives such requirements)

Add a sentence “The minimal thickness of compound around each free space shall conform to the minimal thickness requirements of 6.5.2.1”

Accepted in principle. Add Table 2 and 3 from IEC 60079-18. These tables contain test requirements. These are links to IEC 60079-18 but this introduces a dated reference.

US-062

1708 6.6 Heading ed Revise heading for clarity 6.6 Specification of coating, encapsulating and moulding materials

Accepted

DE-167

1710 -1712

6.6.1 Ed Change the sentence as proposed by the task group “conformal coating”

The documents according to clause Documentation in IEC 60079-0 shall specify the coating materials (used for conformal coating), the compounds (used for encapsulation) and the plastic materials (used for moulding) when applied to achieve intrinsic safety.

Accepted

US-063

1717 6.6.2 c) ge The specification of Type 1 and Type 2 of conformal coating is only applicable when using column 5 or 6 of Table 6.

c) coating classification: Coating type 1 or type 2 according IEC 60664-3 for conformal coating when using column 5 or 6 of Table 6.

Not accepted. This is only material specification and not a requirement for the application of conformal coating. The standard distinguishes between three different conformal coatings (1. CC acc. IEC 60664-3 Type 1, 2. CC acc. IEC 60664-3 Type 2 and 3. CC without referencing a product standard)

US-064

1719 6.6.2 d) ed Revise for clarity d) the possible required surface treatments, such as cleaning, temperature conditioning, etc.;

Accepted

GB-118

1720 1730 1737

6.6.2 6.6.3 6.6.4

ed COT as defined in 60079-0 is a range, so it is not necessary to include this word in 6.6.2 e), 6.6.3 d), or 6.6.4 c).

Delete ‘range’ in three places. Accepted

US- 1720 6.6.2 e) ge COT is not a value that is commonly specified by Remove item e) from 6.6.2. Not accepted.

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(e.g. Table 1)

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065 for conformal coatings manufacturers, and will therefore be problematic to specify. Additionally, there is no guidance on what the conformal coating’s COT rating needs to meet, so specifying it adds no value, and will cause inconsistent interpretations of the requirement.

It is true, that it is hard to get a TI or RTI value for CC, but the operating temperature for a coating material is a data that should always be available from the coating manufacturer, otherwise it cannot be used for safety purposes. If safety relies on the coating it must last during the lifetime of the apparatus.

DE-168

1722 6.6.2 ed The source of the data for these characteristics shall be identified. In other chapters (e.g. 6.3.4.5) a note is used.

Replace the sentence with the Note: It is not a requirement of this Standard that the conformity of the manufacturer’s specification of the coating needs to be verified.

Accepted. To be consistent with the material specifications in IEC 60079-0 use the same wording as in 79-0

US-066

1724 6.6.3 1 ed Revise for clarity The specification for of compounds shall include the following:

Accepted

CH-37

1726 6.6.3 b) te Compared to the requirements for coating materials, materials used for cementing, elastomers and plastics defined in the IEC 60079 series, the requirement seems to be overtightened.

We would appreciate, if TG can consider the following wording: “the identification of all materials, including their type designations, colour and, where relevant, their percentage within the compound, NOTE to entry: All materials means all ingredients used by the "person"(end user) to compose the casting compound used within the scope of this standard. It is not the intention to request the formula of each ingredient specified by type designations and colour.

Accepted in principle. Use the same wording as for Plastic materials in 79-0: “the identification of the material, including its type designation and colour;” Replace the last sentence in this clause by the following NOTE 1 “: It is not a requirement of this Standard that the conformity of the manufacturer’s specification of the compound needs to be verified.” Do not add the NOTE proposed but instead we propose to add NOTE 2 from 79-0 Plastic materials:

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(e.g. Table 1)

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When selecting materials used for encapsulation, some manufacturers have noted that variations in type and percentage of fillers, flame retardants, ultra-violet light stabilizers, and the like can have a significant effect on the properties of the material.

US-067

1726 6.6.3 Item b) te If we read the second part of the requirement word by word, "if relevant, percentage of fillers and any other additives, the mixture ratios and the type designation" the following assumptions might be valid: • percentage of fillers might be relevant to the

compound independent of the "person (material vendor or end-user)" adding it

• percentage of any other additives might be relevant to the compound, independent of the "person (material vendor or end-user)" adding it.

it may be difficult for manufacturers to get the vendors of the encapsulation to share the exact formula of their product since it is typically considered proprietary. I believe the intent is to clearly capture an instance where a manufacturer may be adding material to the encapsulant when they are mixed, or completing a specific surface treatment for adherence of resin. If this is the intention, then let’s reword this sentence to make it clear.

• the identification of all materials, including their type designations, colour and, where relevant, their percentage within the compound,

NOTE 1 All materials refers to all ingredients added by the end user to compose the casting compound used within the scope of this standard. It is not the intention to request the formula of each ingredient specified by type designations and colour.

Accepted in principle. See CH-37

DE-169

1726 -1727

6.6.3 b) Ed To harmonize the different material specifications, the same wording as for plastic materials and coating materials should be used for materials used for encapsulation. Additionally a NOTE should be added as NOTE 2 in the 7th edition of IEC 60079-0 for the material specification of plastics, to indicate that fillers and additives may have a significant effect on the properties of the compound.

the identification of the material, including its type designation and colour; NOTE When selecting compounds, some manufacturers have noted that variations in type and percentage of fillers, flame retardants, ultra-violet light stabilizers, and the like can have a significant effect on the properties of the compound.


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(e.g. Table 1)

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DE-170


Replace the sentence with the Note: It is not a requirement of this Standard that the conformity of the manufacturer’s specification of the compound needs to be verified.


DE-171


Replace the sentence with the Note: It is not a requirement of this Standard that the conformity of the manufacturer’s specification of the moulding needs to be verified.


GB-119

1742 6.7 te This clause is not clear. Does the “where this could occur” apply to just cells of a battery, or any reversal of polarity? (It should be both) Does this apply to non-intrinsically safe connection facilities in the non-hazardous area? (It should) Is a physically un-reversible connector sufficient? (It should be).

Modify: Protection shall be provided within intrinsically safe apparatus to prevent invalidation of the Type of Protection intrinsic safety as a result of reversal of the polarity, where this could occur, of supplies to that intrinsically safe apparatus or at connections between cells of a battery where this could occur. For this purpose, a single diode rated in accordance with 7.1 shall be acceptable, or mechanical prevention, for example keying or co-axial connectors. NOTE: This requirement includes connection facilities for use only in the non-hazardous area.

Accepted in part, editorial rewording accepted.

BR-06

1748 6.8 1st te Enclosure of a battery powered hand-held device may be made of metallic conductive material. The phrase “may be earthed” is confusing on this situation, given that this enclosure may be earthed if in contact with another conductive earthed surface. Therefore, if the intention of the phrase is to induce this interpretation, then the dielectric strength test should apply for all metallic enclosures or enclosures with metallic parts. Otherwise, it should be replaced by another phrase that clearly stated that these parts shall be earthed by connecting facilities to avoid the interpretation of “in-contact” earthed.

Clarify this requirement based on the example explained in the comment. Possible rephrasing: 1. “Where it is required to maintain intrinsic

safety, the insulation between an intrinsically safe circuit and the frame of the electrical equipment or parts connected to earthing”; or

2. “Where it is required to maintain intrinsic safety, the insulation between an intrinsically safe circuit and the frame of the electrical equipment or any metallic external part of the enclosure”.

Accepted in principle clause slightly reworded for clarity. Note that most battery powered equipment will not need to apply this clause as intrinsic safety will not depend upon isolation from earth.

US-068

1749 6.8 te The wording ‘shall be capable of complying with the test described in 9.3’ is a bit vague, and has been used to argue that a test is not required. Is the intent that a test shall be conducted (with the exception of adequately rated individual components)?

Reword: Where it is required to maintain intrinsic safety, the insulation between an intrinsically safe circuit and the frame of the electrical equipment or parts which may be earthed shall be capable of complying with the test described in tested in accordance with 9.3 at a test voltage…

Not accepted, the clause is worded this way specifically to allow the use of manufacturer data to confirm the ability to satisfy the test voltage. Clause has been reworded and note made normative

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(e.g. Table 1)

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to reinforce this.

AU-37

1750 6.8 1 te The way the DC voltages have been included here can make the clause less clear. It is also noted that some circuits may not pass an a.c. test due to the inclusion of blocking or filter capacitors.

Remove the DC references in the text, and add a new paragraph and note: Alternatively, the test can be performed at a d.c. voltage 1,4 times the specified a.c. voltage. Note: Some circuits, e.g. those designed with blocking or filter capacitors, will pass current under an a.c. voltage which might affect an a.c. dielectric strength test.

Accepted in principle in part. Normative text reworded, however the note was not considered necessary.

DE-172

1754 -1757 and 1758 - 1761

6.8 Te Which voltages have to be added Uo and Um, or max. Non-intrinsic Safety circuit + max. separated circuit voltages? 6.3.3 defines which voltages shall be considered in the application of Table 5, 6, 7, so it may be advisable to use a reference to 6.3.3 instead of a new but also different and incomplete definition.

…where U is the voltage applicable according 6.3.3 a) or b) respectively

Accepted in principle, reference made to just 6.3.3. Change made in two places.

CH-38

1763 7 te Characteristics and failures of thermal trips, non-resettable and resettable devices are missing.

Please consider to address these components in subclauses of 7.

Noted, “Positive temperature coefficient components” clause added prohibiting these devices in the absence of a proposal for requirements for their use.

GB-120

1765 7.1 1st sentence ed The conditions of 5.2 already include normal operation.

Modify text: For Level of Protection “ia” and “ib” in both normal operation and after application of the fault under the conditions givenspecified in 5.2.1 and 5.2.2

Accepted

GB-121

1768 7.1 1st para te “As applicable” is potentially open to abuse as there is no clear definition as to which parameters are not applicable. Instead, rely on “unless otherwise stated in this standard” and include exceptions in each appropriate component type.

Delete “as applicable”. Not accepted, the MT does not consider that this is open to abuse.

GB-122

1769 7.1 2nd para ed “in the conditions defined in 5.2.3” is inconsistent Replace ”in” with “under” Accepted

US-069

1769 7.1 2 te For “ic”, all requirements in the standard are based on a 1.0 safety factor, except for the power rating of protective components which is based on a 2/3 derating. Recognizing that this represents a reduction from

For Level of Protection “ic”, in under the conditions defined in 5.2.3, components on which intrinsic safety depends shall not operate at more than their manufacturer’s maximum current, and voltage rating and no more than two-thirds of their

No accepted. The MT felt that for “ic”, for most of their expected operational life, protective components should not be operated

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“nL”, there is still the question of why this one requirement for “ic” is treated differently than the others. The requirements for testing or assessing the circuits for spark ignition, for determination of surface temperature classification, and for protective components should all involve the same 1.0 safety factor.

power rating. above 2/3rds their rating for power. Wording for this is being considered.

RU-03

1771 7.1 te At the stage of design and selection of the components of the equipment, the manufacturer carries out the analysis of the technical data of the components’ manufacturers, including the data for the components on which the intrinsic safety depends. Typically, the technical data for the components are confidential information of the components’ manufacturers and are transmitted only when the products are bought. These data and the analysis of these data, performed by the manufacturer of i.s. equipment when selecting specific circuitry solutions, are required by the certification body when assessing the intrinsic safety of components. Therefore, when equipment is applied for certification, the manufacturer should provide the data on the technical parameters of the components that will allow the certification body to assess the manufacturer's decisions on the selection of the specific components for compliance with the requirements of IEC 60079-11.

To include the following note after the title of clause 7.1: “Note 1: To assess the intrinsic safety of the circuits to the requirements of IEC 60079-11, the manufacturer should submit to the certification body a calculation performed by the selection of all components on which intrinsic safety depends."

Not accepted. This contravenes IEC’s neutrality principle (see DIR-2 33.1). This is an issue for IECEx OD-017 (ExTAG WG2) It is noted that clause 24 of IEC 60079-0 ed 7 already requires that documentation is prepared which shows the explosion safety aspects to determine compliance, and that for intrinsic safety these explosion safety aspects would include component ratings, etc.

DE-173

1772 ff

7.1 Te For couplers, fault-consideration is excluded for the voltage, current and power. This is a huge simplification. Under fault conditions, the maximum ratings may be exceeded which might destroy the relevant insulation.

Change to “shall be rated for the voltage, current and power in the circuit under the fault conditions of 5.1 (without safety factor)”.

Accepted in principle, these relaxations are covered in the transformer and isolator clauses so the paragraph has been deleted.

IT-10 1772 7.1 ed/te “ … and signal isolators… “ The wording “signal isolators” implies a more complex circuit rather than a component.

Change to “… and other isolating components…” See also IT-19 IT-17 comment

Not accepted, signal isolators is the term used consistently throughout the standard.

GB-123

1774 7.1 3rd para ed Fault conditions are in 5.2, use consistent terminology

Modify text: Under the fault conditions of 5.1 specified in 5.2

Accepted

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(e.g. Table 1)

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GB-124

1778 7.1 4th para, 2nd sentence

ed Putting “the effects of mounting conditions” in the same paragraph as Thermal trips, fuses and switches” implies that this does not apply to anything else.

Start new paragraph at “The effects of mounting conditions”.

Accepted

DE-174

1778 7.1 4th par ed The effects of mounting conditions of components … is related to whole paragraph

Start a new paragraph for this sentence. Accepted

IT-11 1778 ed “The effects of mounting …..” This para should be in a new line as it is referred to the mounting of all components

Insert a new line Accepted

US-070

1779 7.1 ge The draft of IEC 60079-0 Ed 7 uses the term ‘local temperature’ to describe the micro environment ambient temperature that should be considered when rating components. For consistency, ‘service temperature’ in Line 1779 and 1786 should be replaced with ‘local temperature’.

Replace ‘service temperature’ in Line 1779 and 1786 with ‘local temperature’.

Not accepted, “local temperature” is not a defined term and there is no specified method to determine it.

DE-175

1783 -1785

7.1 Example 1 Ed ISO IEC directive 2 requires that Examples are written as statement of facts which are not allowed to contain requirements or permissions.

For a pcb mounted semiconductor the rating is met, if the power dissipation does not exceed two-thirds of the power, which is required to reach the maximum allowed junction temperature under the particular pcb mounting conditions of the semiconductor.

Accepted in part, re-worded: For a PCB mounted semiconductor, the maximum permitted power dissipation is two-thirds of the power required to reach the maximum permitted junction temperature, taking into account the specific mounting and environmental conditions of the semiconductor.

DE-176

1787 -1790

7.1 te Does this also apply to optocouplers/signal isolators which are protected per chapter 7.9.2 by only a zener diode and a fuse? There is no fuse time-current characteristic available for optocouplers/signal isolators. Also Transformes and Relays do not have a fuse time-current characteristic. Test regarding 9.9 is not practicable because the cold resistance of fuses often are only a few mOhm.

Recommend to delete the transients here, because it is already required for semiconductors in 7.6.3 and Diode Safety Barriers in 8.1.1, while excluded for infallible resistors in 9.9 (line 2880, 2881). Alternatively exclude relays, optocouplers and transformers from the transient requirement stating: “This does not apply to galvanically separating components or where components are protected e.g. by a fuse and single Zener diode.”

Accepted, this is now addressed only in 7.6.3 which makes it apply only to semiconductors. Therefore the TG proposes to delete line 1787-1790

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AU-39

1787 7.1 6 te This clause can be incorrectly applied to items which do not need transient ratings verified. For example where the function of the fuse is to protect a component from causing thermal ignition. For this example the transient caused by the fuse rupture is already taken into account as 7.10 requires that 1.7x In is to be assumed flow continuously from the fuse.

Modify the text: Where components on which intrinsic safety depends are protected by a fuse, the fuse shall be in accordance with 7.10 and fuse time-current characteristics shall ensure that the transient ratings of protected components are not exceeded where applicable. Where the fuse time-current characteristic is not available from the manufacturer's data, a type test shall be carried out in accordance with 9.9.

Not accepted, text has been deleted, see DE-176.

GB-125

1788 7.1 5th para te Transient ratings of safety components (except resistors) should be protected for controllable semiconductor limitation as well as fuses. This should all be covered by 9.8. As worded, this transient rating is applicable to resistors which contradicts line 2836 (9.8). It is not necessary to state that fuses have to comply with 7.10 as otherwise it would be necessary to list all of the subclauses and their component types. The safety factor for transient rating is not stated. In Ed.6, contrary to the statement in the last sentence of 6 7.3 1st paragraph, the test in 10.4 did not include a 1.5 safety factor, neither did the test in 10.8. Therefore clarify that the safety factor is only 1,0.

Replace paragraph with: Unless otherwise stated in this standard, components on which intrinsic safety depends shall be capable of withstanding transients during the switching of any current limitation on which they depend (for example by a fuse) with a safety factor of 1,0. This shall be tested or assessed in accordance with 9.8.

Not accepted and now deleted, see DE-176. However, note that 7.6.3 addresses the evaluation of the transient rating and the TG has not reached consensus about the safety factor part of this comment.

GB-126

1788 7.1 5th para ed The set of values is a “rating” according to 79-0. Change “ratings” to “rating” Accepted

CH-39

1790 7.1 Reference to type test seems to be wrong. Clause should read 9.4 instead of 9.9.

Correct clause to 9.4 Not accepted, see DE-177, GB-127, US-071. Reference to 10.4 in editions 5 and 6 is considered an error that occurred when the clauses were re-numbered following Ed.4.

DE-177

1790 7.1 te Reference to 9.9 is wrong, because 9.8 seems to be the new test replacing 9.9.

Change reference from 9.9 to 9.8 Accepted

GB-127

1790 7.1 5th para ed Tests in 9.8 are a replacement for 9.9 which should be deleted.

Change reference to 9.8. Accepted

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US-071

1790 7.1 5th para ed I think the wrong clause is referenced – 9.9 should be 9.8?

a type test shall be carried out in accordance with 9.9 9.8

Accepted

DE-178

1791 to 1793 and 1803 to 1805

7.1 6th and 8th para

ed These two para’s should be kept together (I’m still not convinced that it is worth to repeat in 7.1 what is already required in 6.2.5,)

Either move para 6 down to become para 7 or move para 8 up to become para 7 Consider again if it make sense to repeat what is required in 6.2.5 with a more clear consensus.

Accepted, support deletion of 1791 to 1793

GB-128

1793 7.1 6th para ed “required faults” is not clear. Replace “required faults in the intrinsically safe apparatus” with “faults in the intrinsically safe apparatus according to 5.2”

Accepted in principle but propose to follow DE-178 to delete the para

DE-179

1801 7.1 Example 2 Ed Exchange the “may be” with “is” A Zener diode stated by its manufacturer to be 10 V + 10 % is taken to be 11 V maximum and effects such as voltage elevation due to rise in temperature are not taken into account.

Accepted

GB-129

1803 7.1 ed End user accessible in-circuit programming connections should be permitted provided the connections comply with 6.2.5.

Add "NOTE 3: This does not prohibit end user accessible in-circuit programming connections that are either intrinsically safe or comply with 6.2.5". (CC)

Accepted in principle, paragraph reworded to make the note unnecessary

GB-130

1808 7.2 1st para te Clarify “failure” given that this is not the same as the 79-0 definition for “malfunction”.

Add “to meet manufacturer’s specification” after failure.

Not accepted, proposal does not cover all types of failure.

GB-131

1809 7.2 1st para te Ed. 6 7.6 a) stating that the failure of components which are not rated to 7.1 is a non-countable fault is missing, although there are exceptions.

Add to end of 1st para: Where a component is not rated according to 7.1, its failure to any resistance, between any combination of its pins, shall be a non-countable fault unless stated otherwise in this standard.

Accepted

GB-132

1809 7.2 1st para ed “fault mode” is deprecated by IEC 60050 Replace with “failure mode” Accepted

GB-133

1810 7.2 2nd para te It should be clarified that components are not considered to fail for “ic”.

Modify: For Level of Protection “ic”, consideration of the failure of a component to meet its manufacturer’s specification is not required. cComponents that are not used within their ratings as required by 7.1 may not be used as components on which intrinsic safety depends.

Accepted in principle, also changed “may not” to “shall not”.

GB-134

1810 7.2 2nd para ed The set of values is a “rating” according to 79-0. Change “ratings” to “rating” Accepted

GB-135

1811 7.2 2nd para ed “may not” should not be used for prohibition (DIR-2 Table 3)

Replace “may not” with “shall not” Accepted

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(e.g. Table 1)

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GB-136

1812 - 1815

7.2 3rd para te This paragraph contradicts the two previous paragraphs. It came from Ed.6 6.3.6 “Separation distances through solid insulation” so is really about not having to consider the separation. The default principle that separation inside components does not need to be considered is catered for by GB comment on line 1148 (6.3.1).

Delete paragraph Accepted

DE-180

1821 -1823

7.3.1 te/ed printed resistors are missing. In 7.3.2 c) printed resistors are mentioned and a rating of 1,0 for thermal ignition compliance is stated in the remarks of Table 9

Add printed resistors to 7.3.1 or exclude printed resistors in the remarks of Table 9

Accepted in principle, changed “film and wirewound resistors” to “resistors of the types described in 7.3.2”.

IT-12 1826-1827

7.3.2 ed “…Table 10.” Wrong reference

Change to: “.. Table 9.” Accepted

AU-40

1827 7.2.3 1 ed Referring to the wrong table Table 9 – Failure modes of resistor Table 10 – Failure modes of capacitors

Modify the text: Resistors, including current limiting resistors, rated in accordance with the requirements of 7.1 1 and complying with the following shall be considered as capable of failing according to Table 9. Accept

Accepted

DE-181

1827 7.3.1 ed reference to table 9 instead of table 10 Change reference to Table 9 Accepted

GB-137

1827 7.3.2 1st sentence ed Reference should be to Table 9. Change reference to Table 9, replace space with hard space so the reference is not split across lines.

Accepted

BR-07

1827 7.3.2 1st ed The text is referring to Table 10, however the failures modes for resistors are given on Table 9.

Replace “Table 10” by “Table 9”. Accepted

GB-138

1828 - 1834

7.3.2 Table 9 te In Ed.6, resistors that were rated to 7.1, but were not of the types defined in 8.5, were considered to fail to any resistance as a countable fault. This is now missing. Similarly, in Ed.6, resistors on which “ic” depended did not need to be of a type defined in 8.5. However, this new arrangement means that they now do. The “considered value” R ±Tol is not a failure so should not be in the table. See also GB comment on proposed new subclause 5.2.4 which covers this and the first part of the NOTE.

Replace “Failure mode” and “Considered value” part of the table with:

Failure mode

Open circuit Short circuit

Resistance out of specification

countable fault

countable fault*

countable fault*

Not applied Not applied Not applied

Move 2nd paragraph (1828 to 1833) to top of the

Not accepted. MT accepted that this is a technical change, and that carbon composite resistors (and other unspecified types) may no longer be used as protective devices for “ia”, “ib”, or “ic”. Table title changed to “Rating and failure modes of resistors”.

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foot of the table and modify as follows: *Resistors shall be of one of the following types may be considered as failing only to open circuit and to be infallible against failure to a resistance other than its manufactured value: a) …” etc Delete NOTE at the foot of the table up to “Once assembled” which should stay but as normative text.

GB-139

1834 7.3.2 Table 9 te Improve language of “As for the voltage rating”. “constant value” is not sufficiently clear.

Make the sentence at foot of the table “Current ratings are not normally specified….” into a note. Replace second sentence with: “The voltage and current rating shall be those specified by the manufacturer for the resistor construction and not a de-rating based on the resistance. These do not need to be considered if no such rating is specified by the manufacturer.”


BR-08

1834 7.3.2 Table 9 te Rating resistors to avoid thermal damage is known to rely on power rating. Resistors dissipated power has an exponential relation with voltage and current, therefore, if it is required to achieve the minimum safety factor 1.5 over the rated voltage and the rated current, the power should be required to provide a safety factor minimum 2.25 (1.52). Otherwise, it should be explained on this table that rating to avoid thermal overloading is based on power and low resistance resistors on current with dielectric strength and/or insulation based on voltage. i.e. There are TL’s that use to calculate the rated

voltage by and then the safety factor is applied over this rated voltage. Given the exponential relation with power, this approach necessarily requires a safety factor 2.25 over the nominal power to achieve the safety factor 1.5 over the rated voltage.

The committee should consider two possibilities to align the methodologies:

1. Specify the safety factor 1.5 for power, current and voltage and replace the 2nd phrase in the table remarks from “As for the voltage rating, the specified constant value shall be used, and reduction of the rated voltage due to the resistance shall not be considered” to “The voltage rating is for dielectric strength and shall consider the specified constant dielectric strength rating. Thermal overload is rated by the nominal power”; or

2. Specify the safety factor 1.5 for voltage and current and 2.25 for power to align the interpretations and ensure the application of this clause by the same methodology by all TL’s.


DE-182

1834 7.3.2 Table 9, N. ge What does “specified constant value” mean? clarify Accepted in principle, see GB-159.

AU-41

1834 7.3.2 Table 9 Ed Currently the text has the words ‘specified constant value’ which is difficult to interpret:

Revise to: “The voltage rating used shall be the maximum


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“As for the voltage rating, the specified constant value shall be used, and reduction of the rated voltage due to the resistance shall not be considered” Unfortunately, there is no standard term for the voltage in question and every component manufacturer uses a different term. After much discussion, the AU committee decided that “maximum continuous permissible value” best captured the intent. The word ‘continuous’ was included to avoid the use of higher transient voltage limits (i.e. those with a time limitation).

continuous permissible value specified in the component datasheet, and reduction of the rated voltage due to the resistance value shall not be considered.”

DE-183

1834 7.3.2 Table 9 Ed Exchange the “may be” in the 2nd sentence of the NOTE with “is”

This is the nominal value… Accepted

GB-140

1834 7.3.2 Table 9 ed The contents of “Remarks” is a repeat of 1821, there is no precedent for the status (normative / informative) of a “Remark” in DIR-2. The scope of this changes depending on the acceptance of GB comment on 1828.

Delete “Remarks” column. Accepted in principle, text retained as a note under the table.

GB-141

1834, 1868, 1908, 1973, 2199

7.3.2, 7.4.2, 7.5.2, 7.6.2, 7.9.2

Table 9, 10, 11, 12, 14

ed The second row of these tables is not obviously a title row. See Table 16 for example of correct format.

Make text in row bold. Merge cells with cells above where there is only one title row.

Accepted

GB-142

1840 7.3.2 te Ed.6 10.8 stated that resistors in safety barriers shall be considered to be capable of withstanding any transient to be expected from the power supply. This currently remains in 9.8. It is not clear when transient rating of resistors is required. If there are no occasions when the transient rating of a resistor should be considered then that should be stated.

Add new paragraph “Resistors shall be considered capable of withstanding any transient to which they might be subjected.”

Not accepted, TG does not believe transient rating should be required for resistors. As result of all the transient task group rewrites, no requirement indicates transient ratings of any kind should be evaluated for resistors whereas this was somewhat unclear in 6th edition.

AU-42

1842 7.3.2 4 te Reword to clarify that CU2 is not applied to when dealing with large capacitance values.

Modify the text: Where a resistor and capacitor are connected in series to protect the discharge from the capacitor, during discharge of the capacitor the resistor may be considered to dissipate power in watts numerically equal to the smaller of CU² or U2/R,

Accepted

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where C is capacitance in farads, U is voltage in volts and R is resistance in ohms.

GB-143

1843 - 1850

7.3.2 5th para 1st sentence

te The sentence “Where the resistance of a fuse” has become convoluted. It should be worded as permission. Is “used in normal operating rating” under the conditions of 5.2, or normal operation? Prevention of arcing of a bulb would require this to be under the conditions of 5.2. The first paragraph says you can use the filament of a bulb, then the second says that only applies in some circumstances which seems convoluted. Is the failure of the resistance to less than the cold resistance a countable fault, or is it infallible? Ed. implies it is infallible since this text was in clause 8, so that should be made clear.

Replace both paragraphs with: The resistance of a fuse that meets the requirements of 7.10 may be used for resistive limitation for the protection of other components. The filament of a bulb for hand lights, cap lights or an infra-red source in a gas detector or analyser, may be used for resistive limitation where the bulb is operated within its rating under the conditions specified in 5.2. Where a fuse or the filament of a bulb is used for resistive limitation, the resistance shall be the minimum resistance at the minimum specified service temperature of the apparatus. This shall either be as specified by the manufacturer of the fuse or bulb, or taken as the minimum value measured from 10 samples as required in 9.4. This resistance may be considered infallible against failure to a lesser value

Accepted in principle. Reference to protection of other components limits the application of this resistance. The requirement that fuse resistance cannot be used to limit the current flowing through the fuse is covered in the fuse clause and does not need to be reiterated here.

DE-184

1843 +1845 +1848 +1849

7.3.2 te Filament of the bulb – try better wording Where the resistance of a fuse or a filament of an incandescent light bulb is also used for current limitation …”

Accepted

AU-43

1848 7.3.2 6 te Situations where the filament of a bulb is an acceptable current limiting resistance have been expanded from previously just hand lights and cap lamps to also include IR bulbs in gas detectors/analysers. If this extension is accepted, is there any technical reason the filament of ANY bulb could not be used as a current limiting component? Deleting the restriction would permit this in any potential future application.

Delete this paragraph. Not accepted, further applications which would require a bulb are not known and there is not agreement within the MT to make this a generic requirement.

GB-144

1864 2410-2425 2688-2785

7.41 7.14 9.5

ed For consistency, change “supercapacitor” to “electric double-layer capacitor” throughout.

Change “supercapacitor” to “electric double-layer capacitor”

Not accepted, see JP-19.

GB-145

1868 7.4.2 Table 10 te “Considered value” does not state whether the value is considered before or after the countable

Replace “Failure mode” and “Considered value” part of the table with:

Not accepted. Table title changed to

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fault. For “ia” and “ib”, a value less than specification is a countable fault (i.e. it is a failure mode), and higher than specification is not considered. For all Levels of Protection, a value within C± Tol is not a failure so should not be in the table. There are no remarks in the remarks column

Failure mode

Open circuit

Short circuit

Lower capacitance

Higher capacitance

countable fault

countable fault*

countable fault

Not applied

Not applied Not applied Not

applied Not applied

Delete remarks column.

“Rating and failure modes of capacitors”.

IT-13 1868 7.4.2 Table 10 ed There are no Remarks in the table. Delete column “Remarks” Accepted

AU-44

1869 7.4.2 2 Ed There seems to be unnecessary ‘but’ in the text: “Where the failure to short-circuit is a countable fault, but the separation requirements shall not be applied to the interior of capacitors.”

Revise to: “Where the failure to short-circuit is a countable fault, the separation requirements shall not be applied to the interior of capacitors.”

Accepted

US-072

1869 7.4.2 ed The sentence beginning with “Where the failure…” is not a coherent sentence.

Remove the word “but”. Accepted

DE-185

1870 7.4.2 2nd para (below Table 10)

ed The “but” after the comma was not in the resulting text after the MT’s discussion

Delete “but” or reword sentence to “Where separation requirements of 6.3 are not applied to the interior of the capacitor, failure to short circuit shall be a countable fault.”

Accepted first proposal Second was not accepted as 1/3rd of Table 5 could be applied and failure would still be a countable fault.

FR-19

1870 7.4.2 2nd ed Typing error Delete “but” Accepted

GB-146

1873 7.4.2 te For infallible blocking capacitor assemblies in i.s. to i.s. circuits at low voltages (i.e. approx. 10 V) is it reasonable to require a 500V capability? Would it not be acceptable to require a rating of at least 1.5 times the fault voltage?

Add “For infallible blocking capacitor assemblies in an i.s. to i.s. circuit the capacitors shall be rated at 1,5 times the maximum fault voltage.”

Not accepted, this applies in cases where only 2 capacitors are required, and therefore the increased reliability of the dielectric strength test is desired.

GB-147

1877 7.4.3 te Requirements are given for ‘ia’ but nothing is specified for ‘ib’ or ‘ic’ It is implied that two blocking capacitors are acceptable for ‘ib’ but are there any constructional requirements that are needed for ‘ib’? Do they still need to comply with 6.8 (See GB comment on 7.4.2)

Re-arrange for clarification; “Where intrinsic safety depends on it, electrolytic capacitors, including tantalum, shall not be used to block DC current. For Level of Protection “ia” only two series capacitors are required for DC blocking provided

Accepted in part, reworded slightly.

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that the capacitors: – comply with 7.4.2 (except for internal separation complying with 6.3.2.2); – are of a solid dielectric type; and – where each capacitor complies with the insulation requirements of 6.8 Where capacitors: – comply with 7.4.2 (except for internal separation complying with 6.3.2.2); – are of a solid dielectric type; and – where each capacitor complies with the insulation requirements of 6.8 only two series capacitors are required for DC blocking for Level of Protection “ia”. Either of the two capacitors shall be considered as being capable of failing to short or open circuit.

DE-186

1881 7.4.3 ed blocking capacitors do not need to comply with internal separation with 6.3.2.2. Sentence might be misunderstood.

Reword sentence in Brackets: Blocking capacitors do not need to comply with internal separations according to 6.3.2.2

Accepted in part, reworded as capacitors do need to comply with 6.3.2.2 if there is only one for “ia” and “ib”

GB-148

1883 7.4.3 ed The bullet point refers to ‘insulation requirement’ but 6.8 is a dielectric strength test.

Use consistent terms, i.e. ‘dielectric strength requirement’

Accepted

BR-09

1884 7.4.3 2nd ed The permission of two capacitors only for “ia” can be extrapolated by interpretation to allow one capacitor for “ib”. The committee should consider rephrasing to ensure no incorrect interpretation.

Rephrase for: “…only two series capacitors are required for DC blocking for Level of Protection “ia” and “ib”…“.

Not accepted, these requirements do not apply to “ib”.

IT-14 1884 7.4.3 te “ only two series capacitors … “ia”. Does it mean that only one capacitors is required for Level of Protection “ib” and “ic”?

Clarify and , in case, delete “only” Accepted

DE-187

1886 -1894

7.4.4 Te The title of this clause suggests that capacitors (filter capacitors) exist, which are treated as infallible. However, reading the whole clause only capacitors that meet infallible separation requirements externally and internally are infallible capacitors. This is not new, but is already covered in 7.4.2.

Delete “infallible” in the clause title and keep the title from 6th edition: 7.4.4 Filter capacitors

Accepted

GB-149

1888 7.4.4 2nd sentence

ed Wording is slightly convoluted as infallible separations do not fail. Clarify that it is the short circuit failure that is the issue, not open circuit.

Replace “Where their failure by-passes” with “Where their failure to short circuit would bypass”

Accepted

GB- 1890 7.4.4 Last te This is already stated in 7.4.2. Infallible Delete sentence (better still, delete the whole Not accepted, sentence not

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150 sentence separation is now 6.3.2.2. subclause). a conflict and thought to have value in this clause.

GB-151

1897 7.5.1 te Common mode choke coils such as those used for emi suppression filters fall under the requirements of this clause. In normal operation, the effects of the current flowing through the windings means that the effective inductance is zero. However, using this clause means that one side of the inductor can short-circuited, either;

a) in the component itself or b) by a fault to the case of the apparatus.

In condition a) the components are unlikely to meet the spacing rules for i.s. In condition b) this can be overcome by making the circuit after the component spacing to the case (earth) infallible at the supply voltage

Add a new section. 7.5.4 Common mode choke coils (EMI suppression filters). EMI suppression filters shall comply with the fault conditions of 5.2 as applicable. For Level of Protection ‘ic’ these components are considered as to have an inductance of zero. For Level of Protection ‘ia’ or ‘ib’ unless the construction of the component is well defined and meets the creepage and clearance requirements of this standard both internally and externally the inductance of these components shall be based on the value assuming one winding is short-circuited. Alternatively the circuit shall be arranged such that….

Accepted in part, text simplified. Further development is required.

GB-152

1897 7.5.1 1st sentence ed It is not clear what “This clause” refers to. Replace “This clause” with “Subclause 7.5” Accepted in principle, paragraph deleted as it is adequately covered by the title of 7.5.

FR-20

1899 7.5.1 2nd te Edition 6, cl 7.6, h) deals with “failure of inductors to open-circuit and any value between nominal resistance and short-circuit”. But line 1899 of ed7 considers the failure of inductors to “any value of resistance between open circuit and short circuit”. It is probably not the willing to do this technical change.

Change the sentence to go back to ed6 requirement, as follows: “If not complying with 7.5.2, 7.5.3, or 7.5.4, the failure of inductors to open-circuit and any value between nominal resistance and short-circuit shall be taken into account and shall be considered a non-countable fault. »

Accepted

DE-188

1900 7.5.1 ed Text does not specify which specification should be combined to calculate the inductance to resistance ratio.

Only inductance to resistance ratios lower than that derived from the nominal inductor specifications shall be considered. The inductance is not considered to increase from its maximum rated value.

Accepted

GB-153

1904 7.5.1 Note ed It is not clear what “this clause” refers to. Replace “this clause” with “subclause 7.5” Accepted in principle, omit subclause.

GB-154

1907 7.5.2 1st sentence te Table 11 does not apply to damping windings or inductors made by insulated conductors.

Add to end “unless stated otherwise in this standard”

Accepted in principle, make specific reference to 7.5.3 and 7.5.4

GB- 1908 7.5.2 Table 11 te Considered value does not state when this is Replace “Failure mode” and “considered value” Accepted in part, last bullet

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155 applicable. For resistance, failure to 0 to R-Tol for “ia” and “ib” is a countable fault, i.e. a failure mode. It is not considered for “ic”. There are several failure modes of inductors that could impact on intrinsic safety where external series resistance is lower than the internal resistance.

part of the table with:

Failure mode

Open circuit

Short circuit

L or L/R above specification

Other failure modes*

countable fault

countable fault

not applied

countable fault

not applied

not applied

not applied not applied

*Other failure modes that shall be considered are: • Partial short circuit where L/R remains

constant but both L and R reduce accordingly.

• Decrease in inductance with constant resistance, for example as a consequence of a ferrite core breaking

• Increase in resistance due to poor contact but with constant inductance.

point not included.

GB-156

1911 7.5.3 te Are damping windings used anymore in intrinsic safety? This requirement has been in since edition 1 of the IEC intrinsic safety standard. It is possible that these were used in signalling systems in mines that used relays, but are these still used?

Delete 7.5.3. Not accepted, this is used in some niche applications.

US-073

1911 7.5.3 te Is this type of component ever used? Discussions with a number of engineers who work with intrinsic safety indicated that nobody could remember ever using this clause.

Delete clause? Clarify with main committee if this clause is useful.

Not accepted, this is used in some niche applications.

GB-157

1918 7.5.4 1st sentence ed According to 7.5.1, no inductors are considered to increase inductance from the maximum rated value.

Delete “or higher inductance” Accepted

DE-189

1925 1927 to 1928, 1930

7.5.4 1st para 2nd dash a), b)

te The enamelled wire standards listed are outdated and the use of state of the art standards of the 60317 should also be permitted.

Add: “or other equivalent standard of the IEC 60317 series”

Accept in Principle, see added text in 7.5.5 as provided by secretary of TC 55.

GB- 1931 - 7.5.4 Sentence ed The last sentence “The manufacturer shall” and Move1931 sentence back a tab stop, and move Accepted

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158 1933 and note the following note both refer only to the second dash bullet point (and not b)) so should be indented accordingly. NOTE: Indentation of Ed.6 8.4.2 implied that this sentence and note only allied to b) so this proposed indentation is a change from Ed.6.

NOTE forward a tab stop so that they are both in line with “the conductor shall be” and hence are applicable to all of the second dashed bullet point.

GB-159

1945 7.6.1 1st sentence te Both 7.6.2 and 7.6.3 are required Replace “or” with “and”. Accepted

GB-160

1951 7.6.1 1st bullet 2nd sentence

te “However” should not be used for an exception. These diodes are semiconductors on which intrinsic safety depends so should be subject to transient requirements.

Replace bullet point with: - for surface temperature classification, diodes (including LEDs and Zener diodes) operated within the requirements of 7.6.2 and 7.6.3 shall only be considered for the power they dissipate in the forward conducting mode, or Zener mode, as applicable. All other semiconductor devices shall be considered to fail to a condition where it dissipates maximum power.

Accepted

DE-190

1955 7.6.1 Ed “integrated circuits …” Clarification that in the case of an IC fulfills 7.1, the failure is a countable fault.

Add a note Accepted in principle, changed first para of 7.6.2 to “Semiconductors, including integrated circuits, …”

FR-21

1957 7.6.1 2nd para 2nd bullet

te According to DS2012/009, “the application of short and open circuits to the IC/ASIC internals is considered to stop normal functioning of the IC/ASIC.” This information could be integrated in ed7.

Add a sentence after line 1957: “the application of short and open circuits to the IC/ASIC internals is considered to stop normal functioning of the IC/ASIC.”

Accepted in principle, combined with GB-162 and second bullet point also reworded.

GB-161

1962 7.6.1 ed “EEPROMs” is a bit dated. Replace with “flash memory”. Accepted in principle, examples deleted as part of rewording for FR-21/GB-162.

GB-162

1967 7.6.1 te Reflect ExTAG DS 2012/009 Add new bullet point and examples - Where an IC or ASIC participates in a voltage

enhancement or voltage inversion circuit, it may be considered that some failures of that circuit result in the failure to sustain the voltage enhancement. EXAMPLES - If there is a short circuit between an enhanced

voltage output from a switched mode power supply, and a pin of the controller IC, then the

Accepted in principle, combined with FR-21 and second bullet point also reworded.

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voltage enhancement will cease. Hence the enhanced voltage cannot be sustained at other pins, although the capacitive or inductive energy can.

- If the logic function of an IC is stopped, consequent charge and discharge of energy to a capacitor or inductance does not need to be considered.

BR-10

1973 7.6.2 Table 12 te There are several conditions where the maximum power that can be dissipated by a semiconductor depends of heat-sinking conditions. Therefore, this table should include the possibility of determination of junction temperature to rate the dissipated power on semiconductors. It is a common practice between TL’s and it should be included in the standard.

Include a remark: “The safety factor over power, current or voltage can be demonstrated by testing for determination of the junction temperature according to the data provided by the manufacturer. This condition applies when the maximum rated power is provided in function of the assembly or heat-sinking condition.”

Not accepted, already covered in 7.1.

BR-11

1973 7.6.2 Table 12 te There are integrated circuits for current or voltage control that include self-limiting thermal cut-off features. The committee should include a specific paragraph to inform how to proceed with these components. Can the safety factor over voltage, current and power rely on built-in cut-off elements?

Include a paragraph explaining how to proceed with these components that don’t allow overloading and therefore cannot be tested at the maximum power due built-in thermal cut-off elements that avoid the junction to reach the maximum temperature.

Not accepted, the MT was not clear on why BR requires this to be included. BR is requested to provide further information and suggested text.

GB-163

1973 7.6.2 Table 12 te It is not always possible or necessary to comply with all three of U, I and P ratings (e.g. Zener diodes). However, just noting Zener diodes as an exception does not allow for other situation where a safety factor does not apply (e.g. forward voltage rating of a diode). .

Delete “Remarks” column. Add below the table: Semiconductors on which intrinsic safety depends shall be rated with a safety factor on all manufacturer specified voltage, current and power rating, except where exposure to that rating is internally limited and that limitation is subject to another safety factor applicable rating. EXAMPLE 1:

1,5 U is not applicable to voltage defining semiconductors such as Zener diodes

EXAMPLE 2: Forward rating of diodes, including capture diodes for integrated circuits, that meet the 1,5 safety factor for current do not also need to be assessed for voltage.

Accepted in principle, remark moved to under the table and text RE forward conduction of diodes included.

DE-191

1975 7.6.2 After table ge In 7.9.2 line 2208 is the semiconductor named as an example for a hermetically sealed component.. To add “sealed” here is superfluous.

Change to: …shall not be applied to the interior of a semiconductor.

Not accepted, 7.9.2 just gives semiconductors as an example of something

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which might be sealed, it does not state that all semiconductors are sealed.

GB-164

1977 7.6.3 te Reference to 7.1 implies 1.5 SF for “ia” and “ib” whereas there was no SF in Ed. 10.8 test. 2nd para should also apply to current rating (e.g. test in Ed.6 10.8). Transients though current and voltage limitation should be taken into account for IS apparatus as it cannot be concluded that such transients cannot cause damage, e.g. current limitation from a battery can deliver a very high current for a short period, a Zener protecting an inductor should be rated for the energy stored in the inductor.. NOTE 2 first two bullet points come from Ed.6 8.7.2 a) and b) which are normative exclusions from consideration of transients in associated apparatus, not IS apparatus. They should remain as such. Last paragraph 1st sentence is just an attempt to describe fault analysis which is unnecessary (this is not a user guide).

Re-write clause: 7.6.3 Transient effects on semiconductors on which intrinsic safety depends In addition to the transient requirements of 7.1, semiconductors protected by voltage limitation (such as a crowbar) shall be rated with a safety factor of 1,0 for the maximum voltage to which they are subjected during switching. A suitably protected single transient limiting shunt device such as a Zener diode may be used to reduce the maximum voltage during this transient. NOTE: For level of protection “ia” and “ib”, a single transient limiting device is not sufficient to limit let-through energy for the purposes of spark ignition limitation. Within intrinsically safe apparatus, transient effects other than during the limitation of voltage or current that are generated within the apparatus do not need to be considered for the transient rating of semiconductors. EXAMPLE

Transients generated by switched mode supplies.

Overvoltage transients on Um and Ui do not need to be considered. In associated apparatus, transient rating does not need to be considered for shunt semiconductors used only for the following: a) voltage limitation of the discharge from energy storage or transducer devices, for example inductors or piezo-electric devices; b) limitation of voltage applied to energy storage devices, for example capacitors.

Accepted in principle, reworded.

BR-12

1979 7.6.3 1st te Given that Um and Ui can be alternate current and the values are specified in r.m.s, the values used for transient analysis should be the peak values as required in the line 1992.

Replace “Transient voltages higher than Um and Ui do not need to be considered.” by “Transient voltages higher than the peak Um and Ui do not need to be considered.”

Accepted in principle, covered by proposal in response to GB-164

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AU-45

1984 7.6.3 4 te NOTE 2 is not clear whether the semiconductors in the example need to be rated for transients or not. Clarify the wording. Use the appropriate example formatting.

Modify the text and make an example per DIR 2: NOTE 2 Examples of semiconductors in which transient effects are not considered are: -shunt semiconductors used for the voltage limitation of the discharge from energy storage or transducer devices, for example inductors or piezo-electric devices - shunt semiconductors used for the limitation of voltage applied to energy storage devices, for example capacitors - transients generated by switched mode supplies.

See GB-164

DE-192

1984 7.6.3 3rd para, Note 2

Te /ed Why is this text (normative text of 8.7.2 / 6th Ed.) put in a Note? As there is only one Note, Note 2 is wrong anyway. The first two items may be combined into one as in both cases the concern is the discharge of energy to the shunt semiconductors.

Make it a list of normative text: In intrinsically safe apparatus, any other transient effects shall be ignored for the purpose of component rating. This includes transients generated by switched mode supplies, discharge of energy from energy storage or transducer devices like inductors, capacitors or piezo-electric devices to voltage limiting shunt semiconductors

See GB-164

US-074

1984 7.6.3 ge The examples given are not consistent, and not clear what they are examples of. The first 2 seem to be examples of semiconductors on which intrinsic safety depends, while the last item is an example of how transients are generated. Also, examples have their own format and do not need to be in a Note.

Clarify the examples. See GB-164

FR-22

1984 7.6.3 Note 2 te This note is placed just after the paragraph dealing with transient which could be ignored: Does this note contain examples of transient which could be ignored? Or simply general examples of transient? “NOTE 2” could be replaced by “NOTE”

Replace the line with: “NOTE Examples of transient which could be ignored are:” Or split these examples in 2 categories: “NOTE Examples of transient which could be ignored are: Examples of transient which shall be considered are:”

See GB-164

DE-193

1994 7.6.3 4th para ed Use of “rated” is wrong here because 7.1 specifies how the time characteristic of the fuse is derived.

Replace “rated” by “derived” Not accepted, due to other changes, clause 7.1 no longer specifies how the

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time characteristic of the fuse is derived. As a result, the proposed changes to 7.6.3 no longer refer back to clause 7.1

GB-165

1996 7.6.3 ed The test in 9.9 has been replaced with the test in 9.8.


DE-194

1996 7.6.3 4th para te modify reference from 9.9 to 9.8 because it seems 9.8 is the new test replacing 9.9?

modify reference from 9.9 to 9.8 Accepted

DE-195

2001 7.6.3 5th para te Exceptions are taken from Ed. 6 clause 8.7.3. Ed. 6 permits more exceptions, which should be mentioned in Ed. 7 as well.

Modify to: … such as: infallible transformers acc. to 7.7.5 or; voltage limiting infallible shunt safety assemblies acc. to 7.6.5; batteries in acc. with 7.11 and diode safety barriers in acc. with 8.1.

See GB-164

GB-166

2004 7.6.4 te Much of this clause is in effect a repeat of 7.1 and 7.6.2. The current wording can be interpreted as requiring Zener diodes to be power rated for their short circuit current rather than just the conditions of 5.2. Tests of 9.1.5.3 should apply to all shunt limiters, not just voltage limiters.

Simplify to: 7.6.4 Semiconductors in shunt limiters Semiconductors may be used as shunt limiting devices provided that they conform to 7.6.2 and 7.6.3. Zener diodes in the Zener mode, and other semiconductors and integrated circuits performing a similar avalanche function, shall be rated according to 7.6.2 for their maximum under the conditions specified in 5.2. Other diodes, Zener diodes in the forward direction, diode connected transistors, thyristors and equivalent semiconductor devices shall be rated according to 7.6.2 for the current that would flow in their place of installation if they were to fail in the short circuit mode. Shunt limiting devices may conduct in normal operation.

Accepted in principle, see rewritten text in next CD.

DE-196

2004 and 2022

7.6.4 7.6.5

ge Annex D deals with controlled semiconductor current and voltage limitation, but a reference within the CD can only be found in 7.6.6 (current limiters).

Add in clause 7.6.4 and 7.6.5 the following reference to annex D, similar to the Note in 7.6.6 The maximum voltage Uo may be exceeded in a brief transient due to the response time of the

Not accepted, reference to Annex D is provided in 5.3.

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(e.g. Table 1)

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circuit. Annex D provides information how to determine the transient energy released.

DE-197

2005 ff

7.6.4 ge Reference to clause 9.1.5.3 is missing. Every active current and voltage limitation semiconductor should be tested regarding transient energy transfer into the intrinsically safe circuit during certain load scenarios.

Add the same sentence like in 7.6.5 line 2039, 2040 at the end of clause 7.6.4: Circuits using active voltage limitation semiconductor circuits shall be tested in accordance with 9.1.5.3.

Not accepted, reference to let through energy is now in 5.3.

DE-198

2008 7.6.4 Te Do not understand the clause “In the following cases, this shall…” and the link to following point a) and b). Rewrite the last sentence.

This shall be confirmed from the component manufacturer's data in case of:

Accepted in principle, sentence revised.

GB-167

2022 7.6.5 te This clause has a number of issues. It would be clearer if this is split into two, one for general shunt voltage limiters, and one for the special cases for infallible limiters where the normal countable fault requirements do not apply. Remove the use of “safety” as this is not used either in 3.8.1 or generally anywhere else in the standard. All functional blocks should be tested routinely. There may be more than two shunt paths and the failure of a shunt path to open circuit should also be considered a countable fault. There is no need to state that three paths are required for “ia”. We should standardise on “controlled semiconductor” rather than either “active“ or “controllable” used in Ed.6. If GB comment on 5.3 / Annex GB-1 is accepted then Let-through energy is now a requirement of 5.3. NOTE 1 should apply to current limitation NOTE 2 applies to all circuits, not just shunt safety assemblies. NOTE 3 is permission so should be normative

Replace with two clauses: 7.6.5 Shunt assemblies A circuit or assembly of components including a controlled shunt semiconductor may be used for shunt limitation provided that the following requirements are met: a) all components shall be rated in accordance with 7.6.2, 7.6.3, and 7.6.4; b) where there are multiple independent shunt paths, the voltage of the assembly shall be that of the highest voltage shunt path; c) the failure of a single shunt path to either open circuit or short-circuit shall be considered a single countable fault (but see 7.6.6); d) circuits using controlled semiconductor limitation shall have each shunt path routine tested separately for its limitation function. e) where a shunt assembly is manufactured as an individual apparatus rather than as part of a larger apparatus, then the construction of the assembly shall be in accordance with 8.1.2. NOTE Controlled semiconductor limitation circuits are circuits that limit the available voltage or current using controlled semiconductor components, such as transistors, thyristors, voltage or current regulators. 7.6.6 Infallible shunt assemblies The following shunt assembly constructions shall be considered infallible against failure to open circuit where they comply with 7.6.5: a) for Level of Protection “ia”, two parallel paths of

Accept in part and in principle – See proposed rewrite. Rationale not provided for requiring a routine test on controlled semiconductor circuits. Note 1 – controlled current limiting circuits are not addressed in this clause. Note 2 – deals with specific situation in which the shunt component is used to protect a reactive component. Note 3 – added to normative text.

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(e.g. Table 1)

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diodes or Zener diodes; b) etc... c) etc...

GB-168

2027 7.6.5 c) te Since the failure rate of active crowbar circuits is significantly higher than all other components that have to be triplicated for “ia”, this largely renders the distinction between “ia” and “ib” worthless.

Delete c) Add to Foreword B): The option for only two active voltage limitation circuits for Level of Protection “ia” has been removed as the failure rate of these functional circuits is considered too high for this Level of Protection.

Not accepted - the group accepted that two circuits are acceptable regardless of complexity.

US-075

2027 7.6.5 c) te Why are only two circuits required? Since circuit could contain components where an open circuit is normally considered as a countable fault, it would seem that three circuits would be necessary.

Delete c) or specify three independent active voltage limitation semi-conductor circuits

Not accepted see GB-168

US-076

2034 7.6.5 ed The lettered list should restart at a) Restart list at a) Accepted in part, numbers use as cannot have two a) in one subclause.

DE-199

2044 7.6.5 4th para, last sentence

ed This sentence repeats what is already required in the 3rd para before.

Delete and consider if moving the 3rd para down to become the 4th makes it more clear or if in addition changing the wording is needed to e.g. “Where circuits use active voltage limitation semiconductor circuits, they shall be tested in accordance with 9.1.5.3.”

Accepted in principle, delete hanging paragraph. Reference to 9.1.5.3 to be provided in clause 5.3.

DE-200

2053 7.6.5 Note 2 ge Spark ignition shall be avoided in any case. This Note must be re-written to be a statement of facts.

NOTE 2 If encapsulation in accordance with 6.5.3 is used, spark ignition is prevented, when a connection breaks.

Accepted in principle, see rewritten text in next CD.

IT-15 2053 7.6.5 NOTE 2 ed Reference to 6.5.3 seems not appropriate Change to 6.5.2 Accepted

US-077

2053 7.6.5 Note 2 ge It is not clear what connections the note is referring to, or under what circumstances the connection will break.

Consider removing Note 2. Not accepted, the note only provides guidance.

DE-201

2056 7.6.6 ge The clause deals with current limiting only. Change title into: “Semiconductor current limiters”

Accepted

GB-169

2056 7.6.6 Title te This sub-clause is about current limitation. Add “current” to the middle of the title. Accepted

DE-202

2057 to 2061

7.6.6 Whole clause

Te/ed The clause was significantly changed, reducing the requirements, so that now electronic current limiters are allowed for "ia".

Reinstall text from 7.5.3 6th Ed. and add a reference to the test in 9.1.5.3 (similar to 7.6.5) The use of three series blocking diodes in circuits

Not accepted, the MT agreed that under some specified conditions these

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(e.g. Table 1)

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There is no such comment in 31G/230A/INF nor any observations noted to make clear why these changes were applied, while the only comment on 7.6.6 (DE-122 on 7.6.5) to require the test in 9.1.5.3 was not addressed. It is not clear how compliance with 9.1 can sufficiently show intrinsic safety for such circuits. The Note in 7.5.3 of 6th Ed. explained the issues. Reference to clause 9.1 is sensible, but not always sufficient, because the ignition curves do not consider dynamic behaviour of electronically controlled current limiters and a test with STA is often not applicable because of dynamic characteristic of the current limiter after a short.

of Level of Protection “ia” is permitted, however, other semiconductors and controllable semiconductor devices shall be used as series current-limiting devices only in Level of Protection “ib” or “ic” apparatus. However, for power limitation purposes, Level of Protection “ia” apparatus may use series current limiters consisting of controllable and non-controllable semiconductor devices. NOTE The use of semiconductors and controllable semiconductor devices as current-limiting devices for spark ignition limitation is not permitted for Level of Protection “ia” apparatus because of their possible use in areas in which a continuous or frequent presence of an explosive atmosphere may coincide with the possibility of a brief transient, which could cause ignition. Circuits using active current limitation semiconductor circuits shall be tested in accordance with 9.1.5.3.

should be able to be used. These conditions are still to be defined.

AU-46

2058 7.6.6 2 Te This is a significant change from previous editions, which now permits the use of 3 series current limiters to provide current limitation for level of protection “ia”. Annex D of the CD considers transients generated within the equipment itself due to delays in operation of the series current limiter, but there is also a possibility of transients in Um which are not adequately considered by the standard. There is also some experience in the AU of common mode failures in these devices due to transients in the mains supply. AU would propose limiting the use of series current limiters to devices other than mains connected equipment, subject to transients. However, we would not want to restrict the use of such equipment where the end user has conditioned the mains supply such that significant transients are not expected.

Add after paragraph 2: Controllable series current limiting devices shall not be permitted for spark ignition compliance for level of protection “ia” circuits which can be affected by transients in the mains supply. Note 1 Controllable series current limiting devices are known to fail to short circuit, due to transients in the mains supply. Note 2 The use of line conditioners or equivalent is a method for the installer to limit transients in the supply to an associated IS equipment.

Not accepted, the majority of the MT are in favour of allowing controllable semiconductor current limitation for “ia”. However, the spark ignition requirements for this now mandate both the use of Annex F (Ed.6 Annex H) and the extended transient energy testing of Annex D (Ed.6 Annex E) which now includes testing faults in the supply.

GB-170

2058 7.6.6 2nd para te There should be various requirement for series semiconductor limitation. If GB comment on 5.3 / Annex GB-1 is accepted

Replace 2nd para with: A circuit or assembly of components including a controlled series semiconductor limiter may be

Not accepted. a), b) and c) are already requirements, and for d) the majority of

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then Let-through energy is now a requirement of 5.3.

used for current limitation provided that the following requirements are met: a) all components shall be rated in accordance with 7.6.2 and 7.6.3; b) where there are multiple independent circuits, the output current of the assembly shall be that of the highest current limit circuit; c) the failure of a single current limit circuit to either open circuit or short-circuit shall be considered a single countable fault; d) circuits using controlled semiconductor limitation shall have each independent functional circuit routine tested separately for its limitation function.

the MT did not feel that routine testing of safety critical functional circuits is necessary due to the reliability of modern PCBA manufacturing.

GB-171

2060 7.6.6 ed “may” should be avoided in a note, “on” is missing from 2nd sentence.

Modify text: NOTE The maximum current IO maymight be exceeded infor a brief transient due to the response time of the circuit. Annex D provides information on how to determine the transient energy released.

Accepted

DE-203

2071 7.7.2 1st para Ed Referenced clause numbers should be in an ascending line

Change to “7.7.3, 7.7.4, 7.7.6 and 7.7.6” Accepted

IT-16 2071 7.7.2 ed Clause numbers “… 7.7.3, 7.7.6, 7.7.4 and 7.7.5… “

Change to: “… 7.7.3, 7.7.4, 7.7.5, and 7.7.6…” Accepted

GB-172

2071 7.7.2 1st sentence ed It is not clear what “this clause” refers to, and is a circular reference. 7.7.2 is a subclause.

Replace “the requirements of this clause” with “the following requirements” Start new paragraph at end of 1st sentence.

Accepted

FR-23

2071 7.7.2 1st ed References are not correctly ordered Reorder correctly Accepted

GB-173

2072 7.7.2 1st para ed The third sentence contradicts the second. Join sentences using “except” (i.e. between “occur” and “for”)

Accepted in part, “except that for…”

GB-174

2076 7.7.2 2nd para ed Listing all three Levels of Protection is unnecessary and potentially confusing as it implies there are other Levels of Protection.

Replace: “relevant for the Level of Protection “ia”, “ib” and “ic”” with “on which intrinsic safety depends”

Accepted

GB-175

2078 7.7.3 Title ed Omission of “Level of Protection” is not consistent.

Change title to: Requirements for infallible transformers for Levels of Protection “ia” and “ib”

Accepted

GB-176


Change title to: Constructional requirements for infallible transformers for Levels of Protection “ia” and “ib”

Accepted

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US-110

2088 & 2092

7.7.4 Par 3 ed Since we are using Type 1 and Type 2 to designate both conformal coating and transformer construction, it may be beneficial to add a note at the end of this paragraph referencing IEC 60085 that these Types of construction has been defined in.

Note: Refer to IEC 60085 for definition of Type 1 and Type 2 construction.

Accepted in principle, note reworded slightly

DE-204

2110 7.7.4 Ed The voltage for dielectric strength test does not mention if d.c. or a.c.

…it shall be capable of withstanding a 500 V r.m.s test in accordance with 9.3.

Accepted

GB-177


Change title to: Protective measures for infallible transformers for Levels of Protection “ia” and “ib”

Accepted

AU-47

2124 7.7.5.1 3 Ed Per the 60079-0 definition of fuse – a fuse is only a device which breaks on current, so thermal fuse is not a term we can use.

Change to : “… an embedded thermal protective device is used for protection against …”

Accepted

DE-205

2132 7.7.5.2 Te Is “mains” and “line” the same? Clarify the meaning of “not directly” by using “not galvanic separated”

Replace “line” to “mains” As these transformers are not galvanic separated to line voltage, but they are protected by a voltage limitation circuit, the reduced test requirements according to 9.11.2 apply Note "directly connected" means that there is no protection by a voltage limitation circuit between mains/line and transformer

Accepted in part. Retain not directly connected to, as changing this to require galvanic separation would be an increase in requirements.

DE-206

2137 to 2138

7.7.5.2 2nd para Ed/te The reference to 7.9.3 b) (coupler's) does not work. It may be better to add appropriate wording here.

Modify text to: "... shall be applied or a single shunt Zener diode protected to a safety factor of 1.0 by a suitably rated fuse according to 7.10 shall be included in ..."

Accepted

FR-24

2138 7.7.5.2 2nd te 7.9.3b doesn’t contain any recommendation on protective measures. 7.9.2 may be the right reference

Replace reference 7.9.3b by 7.9.2 Accepted in principle, see DE-206

DE-207

2139 7.7.5.2 2nd para Ed For consistency use galvanic separation. …power shall not impair the infallibility of the galvanic separation provided by…

Accepted

GB-178

2141 7.7.5.2 Last sentence

ed When such transformers are connected to intrinsically safe circuits and a fuse is not present, then each winding shall be subjected to the maximum current that can flow under the faults specified in 5.2. No faults are specified in 5.2, only the conditions under which faults are considered.

Modify text: When such transformers are connected to intrinsically safe circuits and a fuse is not present, then each winding shall be subjected to the maximum current that can flow under the fault conditions specified in 5.2.

Accepted

GB-179


Change title to: Requirements for transformers for Levels of Protection “ic”

Accepted

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GB-180

2148 7.7.6 1st para te Table 7 might also apply Modify: The requirements of Table 5 or Table 7 shall apply for the external connections of the transformers but Table 5 shall not apply to the internal separations between the windings.

Accepted

DE-208

2148 7.7.6 1st para Te Allow also to apply Table 6 and Table 7 for external separation.

The requirements of Table 5, Table 6 and Table 7 if applicable, shall apply for the external connections of the transformers...

Accepted in part, Table 6 does not apply to “ic”

DE-209

2163 7.8.2 2nd para Ed In general, the term “galvanic separation” or “galvanically separated” should be used consistently.

Where the coil of a relay galvanically separated from the contacts

Accepted

DE-210

2163 7.8.2 Ed Add two commas for better understanding Where the coil of a relay, separated from the contacts by application of Table 5, is connected

Accepted

DE-211

2165 + 2261

7.8.2. + 7.10

Ed Increase the ac voltage up to 253V r.m.s (230V+10%)

253V r.m.s. Not Accepted - 250 V is accepted as mains throughout the standard.

DE-212

2180 7.8.2 Last para Ed For consistency use “galvanic separation” or “galvanically separated”

Alternatively, galvanic separation of relays may be assessed

Accepted

GB-181

2187 7.9.1 ed The original proposal included the word ‘optical’ before the isolators. Removing this leaves the last sentence ‘The requirements of this clause also apply to signal isolators using other technologies.’ Which now seems to be superfluous, what other technologies are not permitted by this as written.

Delete ‘The requirements of this clause also apply to signal isolators using other technologies.’

Accepted

MT 60079-11

7.9.1 Ed Moved text from 9.12 The requirements of IEC 60079-28 do not apply to self-contained optical isolators.

Accepted

IT-17 2188 7.9 ed/te Signal isolators are often intended as galvanically isolated barriers; which is not the case, because here we are referring to components that provide isolation while transferring signals (eg. Optical couplers). See also IT-12 IT-10 comment.

We suggest to change: “Signal isolators” to “Signal isolating components” or similar wording, throughout all 7.9 clauses. Besides, in many places of the text of clause 7.9, the wording “isolators” is used instead of “ signal isolators”

Not accepted Signal isolator is adequately defined within this section.

DE-213

2189 7.9.1 1st para Ed For consistency use “galvanic separation” or “galvanically separated”

…across the galvanic separation and… Accepted

DE-214

2199 7.9.2 Table 14 te Compared to 31G/249/INF the safety factor for power was increased to 1,5, which seem to contradict to 7.1. This is a significant technical change and should be carefully considered.

Reinstall 1.0 safety factor for power at least for optical couplers meeting internal spacing according Table 5

Accepted

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DE-215

2199 7.9.2 Table 14, 2R 5C

Ed For consistency use “galvanic separation” or “galvanically separated”

Short circuit across the galvanic separation Accepted

DE-216

2199 7.9.2 Table 14, 5R

Ed For consistency use “galvanic separation” or “galvanically separated”

…short circuit across the galvanic separation need not to be considered

Accepted

AU-48

2199 7.9.2 Table 14 ed See DIR 2 - change “need not” to “shall not” Modify the text: *Countable fault except signal isolators complying with 7.9.3 or 7.9.4 failure to short circuit across the separation shall need not be considered.

Not accepted, this is permission not to consider per DIR-2 Table 5.

IT-18 2199 7.9.2 Table 14 ed There are no Remarks in the table. Delete column “Remarks” Accepted

AU-49

2200 7.9.2 2 ed Clarify that the clause is referring to the signal isolator

Modify the text: Where external protective components are required to fulfil the rating of the signal isolator, countable faults shall not be applied to the protective components and component ratings shall have a safety factor of 1.0.

Accepted

GB-182

2201 7.9.2 2nd para ed The set of values is a “rating” according to 79-0. Change “ratings” to “rating” Accepted

DE-217

2202 7.9.2 2nd para Ed To allow safety factors greater than 1.0 an “at least” should be added

…component ratings shall have a safety factor of at least 1.0.

Not accepted, this is consistent with the rest of the standard.

DE-218

2203 7.9.2 2nd para Ed “to a safety factor of 1.0” is confusing and does repeat the requirement form the previous sentence. Delete this.

For example, a single shunt Zener diode protected by a suitably rated fuse according to 7.10, or a thermal device, shall be considered as sufficient protection.

Accepted

DE-220

2206 to 2208

7.9.2 3rd para te Is there a certain reason to no longer require internal separation for optical couplers? The old concept should be kept and the new approach of accepting isolators which meet appropriate standards should have been an added as an alternative.

add to the end: except as required in 7.9.3 a). Accepted in principle, recommend a separating concept and adding a new paragraph subsection. Add internal distance option for optos in 7.9.3 See AU-52

DE-219

2207 7.9.2 3rd para Ed Instead of “coupler” use “signal isolator” for consistency

…applied to the interior of the signal isolator if encapsulated…

Accepted

AU-50

2207 7.9.2 3 ed The clause is referring to signal isolators, remove with word coupler for consistency

Modify the text: The external connections of a signal isolator shall comply with 6.3 but the separation requirements shall not be applied to the interior of the coupler

Accepted

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signal isolator if encapsulated or hermetically sealed e.g. like a semiconductor component.

AU-51

2209 7.9.2 4 te Current transfer limit/leakage current is not typically declared in manufacturer’s datasheets and may be proprietary information. Also, some digital isolators require power on both sides of the isolation to function, making measurement impractical. How is the current transfer limit to be verified?

Refer to signal isolators task group for discussion. Accept in principle See DE-221

DE-221

2209 , 2210

7.9.2 4th para te How can this criteria be met? In an Avago datasheet of an optical isolator there was no specification, while a Toshiba datasheet specifies 50 to 400 % current transfer ratio, which does not match either.

Clarify how to fulfil this additional requirement and if it needs to be added for safety reasons.

Accepted in principle Text modified to not require CTR of an optocoupler in general. Added Note for additional clarity. Propose to add a test for determination of parasitic power leakage in section 9 Concept of parasitic power leakage may need clarification Exclude Optocouplers from this test add the following paragraphs Non-optical signal isolators shall comply with a current transfer limit of 50 μA, as measured by 9.13.1, under the most onerous condition of data rate required for the application under consideration. Optical isolators are excluded from evaluation of transferred current based on the assumption that the energy transferred optically with known architectures is not capable of violating the limit. This exclusion does not apply to optical isolators with a feature to generate or

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(e.g. Table 1)

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transfer power. Propose adding test to section 9.12

DE-222

2209 7.9.2 4th para Ed For consistency use “Signal isolators” Signal isolators shall comply… Accepted

DE-223

2211 -2213

7.9.2 Last para Ed Add “galvanic” to separation for consistency Signal isolators shall comply with the dielectric strength requirements in accordance with 6.8 across the galvanic separation. The manufacturer’s insulation voltage rating for the infallible separation of the component shall be not less than the test voltage required by 6.8.

Accepted

DE-224

2214 2228

7.9.3 Te Do not reduce isolator to signal functionally, delete “Signal”

“Isolators between intrinsically safe…” “Isolators shall comply with …”

Not accepted See IT-17 This excludes power supplies.

DE-225

2215 7.9.3 Ed Either a) b) or c) shall be selected, not all Change to “Signal isolators are considered to provide infallible separation if complying with one of the following:”

Accepted

AU-52

2215 7.9.3 Ge Reading this clause, it could be interpreted to still apply to a signal isolator with internal separations complying with Table 5. The paragraph before the list also seems to suggest that compliance with a) b) and c) is required, when compliance with only one is required. The use of ‘shall’ in each of a), b), and c) also implies this.

Change Para 1 to: Signal isolators are considered to provide infallible separation if complying with one or more of the following: Change ‘shall’ to ‘that’ at lines 2216, 2222, and 2228. Add a new dot point: Signal isolators with external and internal separations that comply with 6.3. Rating of the isolator shall comply with 7.9.2.

Accepted in principle, change c) and add d) as follows: c) Signal isolators that comply with 7.9.2, and in addition comply with the separation requirements of 6.3 applied to the interior of the device. Inside sealed devices column 2, 5, 6, and 7 of tables 5, 6 and 7 shall not apply. d) Optical signal isolators that comply with the test requirements of 9.12. The rating of the optical signal isolator need not comply with 7.1 or 7.9.2, however the dielectric strength requirements of 7.9.2 shall

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(e.g. Table 1)

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be applied. The separation requirements of 6.3 shall be applied to the external connections and to the interior of the optical signal isolator. Inside sealed devices column 2, 5, 6, and 7 of table 5, 6 and 7 shall not apply.

FR-25

2215 7.9.3 1st te The signal isolator shall be compliant with only one of the bullets, not all.

Replace “complying with the following” with “complying with one the following”

Accepted in principle, see AU-52

DE-226

2216 to 2231

7.9.3 a), b), c) te With this, only optical isolators according 60747-5-5 can be used. This at least will lead to re-certification just to verify this. The same applies to the added cross barrier ESD rating. The idea discussed in the MT was to state that in case components specified confirming this standard should be acceptable without requiring further -11 requirements like internal spacing. To keep consensus the external spacings of 6.3 should still apply.

Consider if we need to increase the requirements and reinstall the text of 31G/249/INF (version 3) if this is considered undue. Bring 7.9.3 a) back to the text of 6th Ed. requiring only solid insulation according Table 5 or 6 for sealed couplers and add a new b) with the requirements for optical couplers according IEC 60747-5-5, where there should be no requirement for internal spacings. Only those should be required to have a cross barrier ESD rating, if this data can be verified.

Accepted in principle, addressed by new text for 7.9.2 (DE-221) and 7.9.3 by adding c) and d).

DE-227

2218 7.9.3 a) Ed A verb is missing Change to “The requirements of 6.3 apply for external and internal separations …”

Accepted in part “shall apply to”

FR-26

2218 7.9.3 a) 1st ed The sentence doesn’t contain a verb Replace with: The requirements of 6.3 shall apply for external and internal separations

Accepted in part “shall apply to”

GB-183

2223 & 2231

7.9.3 te Is VDE-0884-11 sufficiently different from IEC 60747-17 for the onerous compliance requirements of IEC DIR-2 10.2.

Delete reference to VDE-0884-11 (two places) Not accepted to cover mismatches in release schedules. VDE will be removed once IEC standard is released.

DE-228

2224 7.9.3 b) Ed Some leftover from copy and paste in the 2nd sentence that needs to be deleted.

Change to “The requirements of 6.3 shall apply for the external separations only.”

Accepted in principle change to: b) Non optical signal isolators that follow the construction and material and test requirements for reinforced insulation according to DIN V VDE-

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(e.g. Table 1)

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0884-11 or IEC 60747-17 with a rated insulation voltage equal or higher than the voltage required by 6.3.3 of this standard. The signal isolator shall additionally comply with 7.9.2

GB-184

2224 7.9.3 b) te Exclusion of columns 4, 5, 6 and 7 of Tables 5 and 6 should apply to internal separations of sealed devices, not external.

Modify: “The requirements of 6.3 shall apply to external separations, except c. Columns 4, 5, 6, 7 of Table 5 or Table 6 shall not apply to the internal separations of sealed devices.”

Not accepted see DE-228

GB-185

2228 7.9.3 c) te As worded, this applies to all isolators between IS and non-IS circuits. Was that the intent? Or was the intent that isolators that comply with 9.12 need not comply with 7.9.2? In Ed.6 the tests of 10.11 only applied if the isolator was not suitably protected to comply with 7.1..

Modify: Signal isolators shall that comply with the test requirements of 9.12 and the isolator ratings need not comply with 7.9.2


GB-186

2228 7.9.3 c) ed The set of values is a “rating” according to 79-0. Change “ratings” to “rating” Accepted in principle, see AU-52

DE-229

2228 -2229

7.9.3 c) Ed Because the test in 9.12 is for optical couplers, this is a requirement that applies only for optical isolators, whose isolator ratings do not comply with 7.9.2, with separations according Table 5 or 6 still required.

Close coupled (single packaged) optical isolators providing internal separation according Table 5 or Table 6, alternatively shall comply with the test requirements of 9.12, if the isolator ratings do not comply with 7.9.2.


US-078

2228 7.9.3 c) te The wording of this clause is rather confusing since it implies that all isolators need to comply with 9.12 whether or not they are adequately rated

Signal isolators shall that comply with the test requirements of 9.12 and the isolator ratings need not comply with 7.9.2.


GB-188

2235 7.9.4 ed The second “shall be” gives the sentence an unintended literal meaning.

Replace second “shall be according to 7.9.2” with “complies with 7.9.2”

Accepted

GB-187

2235 7.9.4 1st sentence te What does “or it can be shown that the circuits connected to the terminals cannot invalidate the infallible separation of the devices” mean? There is no indication as to how this could be done.

Replace quoted text with “or the signal isolators comply with the test requirements of 9.12”.

Accepted in principle, change to: Signal isolators shall be considered to provide infallible separation of separate intrinsically safe circuits if complying with 7.9.2, or 7.9.3d). Protective techniques (such as those

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indicated in 7.9.2) may be necessary to avoid exceeding the rating of the isolating component.

US-079

2235 7.9.4 te ‘…or it can be shown that the circuits connected to the terminals cannot invalidate the infallible separation of the devices’ is insufficiently prescriptive.

Clarify the requirement to demonstrate how it can be shown (e.g. by test), or remove the sentence so that components need to be adequately rated.


AU-53

2236 7.9.4 1 ed Remove pluralisation of device and protective techniques are detailed in 7.9.2 not 7.9.3 a)

Modify the text: Isolators shall be considered to provide infallible separation of separate intrinsically safe circuits if the rating of the device shall be according to 7.9.2, or it can be shown that the circuits connected to the terminals cannot invalidate the infallible separation of the devices. Protective techniques (such as those indicated in 7.9.3 a) 7.9.2) may be necessary to avoid exceeding the rating of the isolating component.


GB-189

2237 - 2238

7.9.4 2nd sentence

te The “protective techniques” from Ed.6 were “For example, the inclusion of a single shunt Zener diode protected by a suitably rated fuse” which is now already stated in 7.9.2, and not in 7.9.3 a).

Delete sentence. Accepted in principle, see GB-187

DE-230

2237 7.9.4 1st para ed Reference to 7.9.3 a) does not work as there are no protective techniques detailed. Possibly it should point to 7.9.2, 2nd para

Consider and change accordingly Accepted in principle, see GB-187

DE-231

2237 7.9.4 Te Reference to 7.9.3 is wrong. Must be 7.9.2 instead. Allow also to use signal isolators as for 7.9.3

Add the sentence: Signal isolators meeting the requirements of 7.9.3 are also considered to be adequate for this purpose.


IT-19 2237 7.9.4 ed/te Why protective techniques as indicated in 7.9.3 a) only?

It should be: “… in 7.9.3 a) or 7.9.3 b)” Accepted in principle, see GB-187

FR-27

2237 7.9.4 1st te 7.9.3a doesn’t contain any recommendation on protective measures. 7.9.2 may be the right reference

Replace reference 7.9.3a by 7.9.2 Accepted in principle, see GB-187

CH-40

2239 7.10 te Characteristics and failures of fuses are not complete yet.

Consider similar presentation in tables as for other components. Copy information from 6.5.1 lines 1554 to 1563

Not Accepted - not a clear proposal

GB-190

2240 7.10 1st sentence te Fuses can be used to protect tracks and connections as well as components.

Replace with: Where intrinsic safety depends on the opening of a fuse, the fuse shall be considered

Accept in Principle, added NOTE: Components in this case includes connectors,

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capable of carrying 1,7 In continuously. PCB tracks, conductors, etc.

DE-232

2240 -2243

7.10 1st para Te Fuses that are not used to provide Levels of Protection “ia” and “ib” and not used as safety devises for Type of Protection “i” can be treated as every other component if they meet the temperature rating for temperature class. In such cases encapsulation is not necessarily required.

Change the sentence to read: Fuses, necessary to provide Levels of Protection “ia” and “ib”, which may carry current when located in explosive atmospheres, shall be encapsulated in accordance with 6.5.

Not Accepted whether the fuse is needed for the level of protection or not, opening of a fuse is an incendive situation.

DE-234

2241 7.10 1st para Ed/te 1st and 2nd sentence should form separate para’s because they address different issues.

Split 1st para into two Accepted

GB-191

2242 7.10 ed “May” is normally used for permission which this is not.

Replace “may” with “can” Accepted

DE-233

2243 7.10 Ed Clarification that also moulded SMD fuses shall be encapsulated additionally.

Add a note Not accepted - fuses must be encapsulated when used in ia, ib area.

GB-192

2243 7.10 te The encapsulation section now contains requirements for both spark ignition and thermal ignition. It is not clear which are applicable to fuses. The thermal requirements (6.5.2.2) seem impossible to meet for a fuse.

Add to end of paragraph “for the purposes of protection against spark ignition. Consideration of thermal ignition is not required.”

Not Accepted - MT does not have consensus.

US-080

2243 7.10 1st para te Consider an allowance for not requiring encapsulation of fuses when the maximum current available is very low compared with their nominal rating – e.g. 10% of In. likelihood of thermal ignition occurring under such circumstances seems very low. Such fuses are sometimes fitted for non-I.S. applications, and not requiring encapsulation could be helpful for manufacturing.

Where fuses are used to protect other components, 1,7 In shall be assumed to flow continuously for the purposes of assessing the components. Fuses for Levels of Protection “ia” and “ib”, which may carry current of at least 0.1 In when located in explosive atmospheres, shall be encapsulated in accordance with 6.5.

Accepted in principle, specified that it is under fault conditions of 5.2.

GB-193

2244 7.10 2nd para te This sentence implies that the rupture of fuses should be considered for spark ignition purposes which is not correct for “ic”.

Delete “thermal” Accepted

GB-194

2244 7.10 2nd para ed There should be no comma after “ic” Delete comma after “ic” Accepted

GB-195

2246 7.10 te We have a test for fuses that are encapsulated. Should there be anything similar for fuses that are coated (fox example by dipping)?

Add that fuses coated using dipping shall be tested in the same manner as fuses that are encapsulated.

Accepted in principle. genericised the term to "or coated" to include spray coating, and other methods of coating.

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GB-196

2253 7.10 5th para te Fuses might be protected from Um or Ui, or there might not be a Ui defined.

Modify text: Fuses shall have a rated voltage of at least Um (or Ui in intrinsically safe apparatus and circuits) voltage rating of at least the maximum voltage that it is subjected to under the conditions specified in 5.2 while open circuit.

Accepted in principle, changed to voltage that it might be subjected to.

BR-13

2264-2265

7.10 6th te The cold resistance of fuses is accepted in the clause 7.3 as a current limiting element and the cold resistance of fuses has been widely used to limit the prospective current, e.g. battery powered circuits, circuits fed by barriers, etc.. This is a change that should be introduced with a specific explanation or be added to the standard.

Delete the phrase “The cold resistance shall not be used for the purpose of limiting the maximum possible current to the breaking capacity of the fuse.” or include an explanatory note with some background to support this change.

Accept in principle - can't use the resistance of the fuse to protect itself. Added clarifying Note 3 on cold resistance usage.

DE-235

2260 ff

7.10 Te Include a note, that the required breaking capacity is AC or DC, as applicable.

Change to “ A fuse shall have a breaking capacity (AC and/or DC, as applicable) not less than …”

Accepted

AU-54

2265 7.10 6 Ed The current text can be improved: “The cold resistance shall not be used for the purpose of limiting the maximum possible current to the breaking capacity of the fuse”

Revise to: “The cold resistance shall not be used for the purpose of limiting the prospective breaking current in the fuse”

Accepted

DE-236

2267 2268

7.10 Ed Add “or component” to device “If a current-limiting component or device is…” “…this component or device shall be infallible…”

Accepted

IT-20 2269 7.10 ed/te Requirement for the separation distances of the limiting device is missing. Last paragraph 7.3 of IEC 60079-11 6th edition, has been removed. Are there any reasons ?

Add. “…with 7.3.2, the distances to other parts of the circuit shall comply with 6.3 and the rated …”

Not accepted, 6.3 is already a requirement of 7.3.2.

AU-55

2272 7.10 7 te Add text detailing the failure modes of the fuse to be assessed.

Add the text: The failure mode of a suitably rated fuse shall only be considered open circuit.

Not accepted The feature to load more capacity into the cell at 0 C charging is not known for WG 37. Charging of secondary cells and batteries shall only be done within the voltage, current and temperature limits as specified by the cell or battery manufacturer.

AU-56

2272 7.10 Ed A fuse only includes current fuses per the definition in 60079-0, but this is not widely

Include a note at the end of this clause reminding the reader that ‘fuse’ only applies to current fuses,

Not Accepted, we do not want to repeat definitions

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(e.g. Table 1)

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understood by readers of this standard. and not to thermal fuses: Note 3 The term “fuse” is limited by definition to only include current fuses. See IEC 60079-0.

that are in 79-0.

DE-237

2272 7.10 Missing last para

te There was a para following, which is deleted now, but there is no comment in 31G/230A/INF and no observation reported on it. Creepage and clearance distances across the current limiting resistor and its connecting tracks shall be calculated using the voltage of 1,7 × In × maximum resistance of the current limiting resistor. The transient voltage shall not be considered. The separation distances between the resistor and other parts of the circuit shall comply with 6.3.

Discuss and consider to possibly re-install the para.

Not accepted - this was addressed by the transients task group and the contents of this paragraph has been addressed in other parts of the standard.

IT-21 2278 7.11.1 NOTE 1 ed NOTE 1 may create confusion in the translation. The concept is that the requirement applies to cells and batteries in associated apparatus when used in hazardous locations and are provided with a type of protection listed in IEC 60079-0

Modify as : “NOTE 1 The parallel battery requirement of batteries of IEC 60079-0 applies also to cells and batteries in associated apparatus that are protected by one of the Types of Protection listed in IEC 60079-0.”

Accepted in principle, changed to: The parallel battery requirement of IEC 60079-0 applies to cells and batteries in associated apparatus that are protected by another Types of Protection listed in IEC 60079-0.

DE-238

2281 7.11.1 2nd para te To my understanding we should not permit cells and batteries which may explode if short circuited. To avoid this risk the intention was to require the use of cells confirming UL1642 or IEC 62133, which are safe. Unfortunately, this is not expressed in this para. Furthermore it is advisable to strictly require measures to prevent from reverse charging.

Consider appropriate revision of the para meeting the intention or wait for more advice from the WG on batteries.

Not Accepted - the current text is considered suitable. Reverse charging is addressed by 79-0.

FR-28

2281 7.11.1 2nd te Compliancy to IEC 62133 is considered as a possibility to achieve the necessary safety level of Li-Ion cells. But IEC 62133 contains tests applicable only on battery, not on a single cell (e.g. case stress at high temperature, external 80mΩ short-circuit at +55°C or overcharging at 2C). Moreover, encapsulation could also have an impact on IEC 62133 compliancy (e.g. inhibition of the pressure relief device)

Modify as follows: “These types of cells and batteries shall conform to the applicable safety requirements of the relevant industrial standards….” Add a note: “NOTE It is not a requirement of this standard to verify the conformity of these types of cells or

Accepted in part - it is only the cells that shall comply with 62133. Note added. Forwarded to WG 37 for review/comment.

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The cell and the battery shall be tested according to IEC 62133 (not only the cell, as currently written)

batteries to the relevant industrial standards requirements.”

GB-197

2287 7.11.1 5th para ed “have to be recharged” gives an unintended literal interpretation.

Replace “have to be” with “are” Accepted

US-081

2300 7.11.2 c) ge To align with definition in the draft of IEC 60079-0 Ed 7, the battery enclosure referred to in item c) should be changed to container (assuming that the enclosure referred to in item c) is an enclosure specifically for housing the cells or batteries, and not the overall equipment enclosure).

Change ‘enclosure’ to ‘container’ Accepted in principle changed to battery container.

US-082

2302 7.11.2. Item C, 1) te Adding commas to clarify meaning since welding would not require additional sealing. Also, remove the ‘s’ at the end of plastic.

Add commas as shown: welding, or adhesives sealed with elastomeric, or plastics sealing devices retained by the structure of the enclosure and held permanently

Accepted

US-083

2310 7.11.2 d) ge A note may be helpful after item d) stating that the encapsulated cells or batteries can be a replaceable battery pack.

Note - Cells and batteries are often encapsulated in a container that forms a replaceable battery pack.

Not Accepted, MT does not believe it adds clarity to the standard.

US-084

2312 7.11.2 Item D ed We’ve got an extra space at the end of 6.5 . Remove extra space so it is 6.5. Accepted

US-085

2313 7.11.2 ge Is a declaration of conformance to a) or b) necessary, or is a datasheet sufficient? A declaration seems excessive for commonly used cells.

A declaration of conformance to a) or b) shall be obtained from determined by the manufacturer’s datasheet of the cell or battery.

Accept in principle, added a note that the datasheet may be accepted as a declaration.

GB-198

2318 7.11.3 te The electrolyte for some cells has a relatively low evaporation point. There may not be any evidence of leakage on the blotting paper or on the external surfaces of the test samples.

Refer to IEC TC31 WG37 for input. Not accepted Some electrolyte solvents may in fact have a low evaporation point, but all electrolytes contain salts, which do not evaporate and would form residues near leaks. Therefore, checking for “visible signs of electrolyte on the blotting paper or on the external surfaces of the test samples”, as written in the test description in

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9.5.2, is sufficient.

US-086

2325 7.11.3 Para. 2 ge The increased concentration of hydrogen is a concern in any enclosure containing electronics, not only in the free volume of the battery container. Also, the equipment manufacturer may be better suited than the battery manufacturer to demonstrate that hydrogen concentration doesn’t build up in the device.

Where the apparatus contains cells or batteries that are charged within them, the battery manufacturer shall demonstrate that the concentration of hydrogen in the free volume of the battery container cannot exceed 2 % by volume, or the degassing apertures of all cells shall be so arranged that the escaping gases are not vented into in any enclosure free volume of the apparatus containing electrical or electronic components or connections.

Accepted.

DE-239

2327 7.11.3 2nd para Ed The term ‘battery container’ is wrong. With the new definitions of ‘battery container’, battery case’ and ‘battery compartment’ in IEC 60079-0, this standard should be edited to use the correct terminology. In most cases ‘battery compartment’ would be the correct exchange for ‘battery container’

Use “battery compartment” Accepted in principle, see US-86 which deletes the phrase.

SE-06

2327-2341

7.11.3 Ed/Te The term “battery container” should be clarified e.g. by a definition. Is it the housing in the equipment manufactured by the equipment manufacturer, where prefabricated cells or batteries are located? Or is it the enclosure of the cell or battery itself, manufactured by the cell or battery manufacturer?

Clarify “battery container” accordingly. For example, should the term “battery container” be changed to “equipment battery housing”, and should this term be defined as the housing in the equipment where prefabricated cells or batteries are located?

Not accepted. See definitions in 79-0

AU-57

2335 7.11.3 3 Ed Para 3 has the same information as in Para 4 (line 2338)

Delete Para 3 lines 2335 to 2337 Accepted

US-087

2335 7.11.3 Para. 3 ge Paragraph 3 (Lines 2335 to 2337) seems to be redundant to Paragraph 4 (Lines 2338 to 2342)

Remove paragraph 3. Accepted

FR-29

2335 7.11.3 3rd te Lines 2335 to 2337 are redundant with the next paragraph (line 2338 to 2342), but less detailed.

Delete lines 2335 to 2337 Accepted

SE-07

2335-2337

7.11.3 4th para Ed/Te Re. the sentence “For rechargeable or non-rechargeable cells the pressure above atmospheric inside the battery container shall not exceed 30 kPa (0,3 bar).”; Is this a general requirement regardless of whether or not it is a sealed battery container subject to the tests according to 9.5.4 (according to the next sentence)? If so, for which operational

Clarify the requirements accordingly; Delete the sentence “For rechargeable or non-rechargeable cells the pressure above atmospheric inside the battery container shall not exceed 30 kPa (0,3 bar).” Clarify and amend the sentence “Battery containers…9.5.4.” to read: “Battery containers that are sealed (no visible

Accepted

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(e.g. Table 1)

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conditions for the cells, does the limit 0,3 bar apply and how does the standard require this requirement to be verified considering that the pressure might depend on the release rate, size of any opening in the container and operational conditions? Or, does the sentence deals with the test for sealed battery containers stated in the next sentence? If so, the sentence should be deleted and the next sentence “Battery containers that are sealed…9.5.4.” should be amended to clarify that it applies for containers with primary and secondary valve-regulated cells or batteries, and that the pressure above atmospheric inside the battery container shall not exceed 30 kPa (0,3 bar) at the test. “Sealed” battery containers shall be tested, but what is considered as “sealed”? If no openings (holes, leaks or slots) can be observed visually, is such a container considered as sealed according to the standard?

vents such as e.g. holes, leaks or slots), for primary and secondary valve-regulated cells or batteries, shall be tested in accordance with 9.5.4 and the pressure above atmospheric inside the battery container shall not exceed 30 kPa (0,3 bar).”

SE-08

2338-2342

7.11.3 5th para Ed/Te The first three sentences “Primary…9.5.4” can be deleted, by considering our proposal above (covered by the proposal). The last sentence “Sealed…9.5.4” remains.

The first three sentences “Primary…9.5.4” can be deleted, by considering our proposal above (covered by the proposal). The last sentence “Sealed…9.5.4” remains.

Accepted

GB-199

2354 7.11.6 Title ed “Level of Protection” is capitalised for consistency.

“Type of Protection” should be capitalised per TC31 GWP 1.7.9”

Accepted

GB-200

2355 7.11.6 NOTE ed Incorrect terminology Modify: “This subclause refers to equipment that is protected by flameproof enclosure (or other technique) Type of Protection”

Accepted

US-088

2358 7.11.6 Para. 1 ge Installation and replacement of the battery should not affect I.S. or the other type(s) of protection. Also, ‘battery housing’ is not a common term. ‘Battery compartment’ may be a better term.

The battery housing compartment or means of attachment to equipment shall be constructed so that the battery can be installed and replaced without adversely affecting the intrinsic safety type of protection of the equipment.

Accepted in part, keep IS type of protection because other types of protection are covered in their respective standards.

GB-201

2362 7.11.6 2nd para ed “is to be” is inconsistent language Replace “is to be” with “shall be” Accepted

GB-202

2364 7.11.6 2nd para ed “can” is not the wording recommended by DIR-2 for permission.

Replace “can” with “may” Accepted

US- 2366 7.11.6 Note 2 ed Note does not meet IEC requirements. Convert to Convert Note 2 to body text. Accepted in part, wording

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089 body text. modified. Current-limiting devices necessary to ensure the safety of the battery are not required to be an integral part of the battery.

GB-203

2378 7.11.8 Title te This subclause only makes sense if the battery is replaceable.

Add “Replaceable” to front of title Accepted

GB-204

2379 7.11.1 1st sentence ed Wording is not clear as to whether current limiting is a requirement or whether it refers to the scope of the subclause. The latter is assumed.

Modify text: If the cell or battery, requiring requires current-limiting devices to ensure the safety of the battery itself, and is not intended to be replaced in the explosive atmosphere

Accepted

DE-240

2382 7.11.8 Te The term “special fastener” is used but the requirements for special fasteners may not be practical or needed since the function of the fastener is not for the same structural requirements like it would be for Ex d. The real concern here is that the battery is not easily accessible, and would require a tool to provide access to batteries.

… compartment secured with special fasteners or an interlocking device according to IEC 60079-0.

Accepted

US-090

2384 7.11.8 a) ed ‘Battery housing’ is not a common term. ‘Battery compartment’ may be a better term.

Replace ‘Battery housing’ with ‘battery compartment’

Accepted in principle, cell or battery housing replaced with battery compartment.

US-091

2393 7.11.8 c) ed There is an extra ‘c)’ at the end of the sentence. End the sentence with ‘…b) or d) or 11.3.’ Accepted

GB-205

2394 7.11.9 te Either the charging connections are for use in the non-hazardous area so are covered by 6.2.5, or they are for use in the hazardous area so have to be intrinsically safe terminals. Hence this clause does not add anything.

Delete sub-clause Accepted

DE-241

2395 to 2397

7.11.9 1st para Ed Instead of repeating the text given in 6.2.5, only a reference to 6.2.5 should be used

Change text: “External charging contacts shall meet the requirements according to 6.2.5

Accepted

BR-14

2395-2397

7.11.9 1st te The loosen phrase “…with means to prevent short-circuiting..” may cause misunderstanding and do not contribute to the alignment when applying the requirements of this standard by different TL’s. The committee should define exactly the requirements to prevent short-circuit.

Include in the text the requirement from clause 7.4.9 b) of IEC 60079-11 Ed. 6: “for Group II intrinsically safe apparatus, a degree of protection by enclosure of at least IP30 shall be provided for the suitably protected charging circuit and shall be marked with a warning label as specified in item c) of 12.3 (or item b) of the text of

Accept in principle see DE-241.

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warning markings table of IEC 60079-0). The separation distances between the charging contacts shall comply with 6.3 considering the open-circuit voltage of the battery.”

JP-21 2411 2412

7.14 1st Para ge The sentence seems unnecessary since there is no requirement in IEC 60079-0 or IEC 60079-11 to prohibit the parallel connection of supercapacitors.

Remove the sentence. Not accepted. The intention was to remove any ambiguity. If Supercapacitors are in all cases treated like cells and batteries it could be assumes that the restriction on parallel connection of these supercapacitors also applies.

DE-242

2413 7.14 Te The first sentence states that the charging system needs to be fully specified. Further definition needed. Does this mean full schematic, BOM, layout, assembly details, performance, etc. Much could be read into this first sentence, and not evenly applied.

Look at additional details in regards to what specifically is the concern and what would need to be controlled. It might be enough to require the limit of maximum voltage, current charge rate, and only the specific details on how it will prevent the U and I from exceeding the super cap limits.

Accepted in principle, see JP-22

JP-22 2413 to 2416

7.14 2nd Para te The limit for the charging current is usually not specified for supercapacitors, as one of their features is that they can be charged instantly with large current.

Replace the two sentences from the beginning of the paragraph with the following. The voltage applied to the supercapacitor shall not exceed the limit specified by the manufacturer, even when faults in accordance with 5.2 are applied.

Accepted

DE-243

2419 -2420

7.14 3rd para Ed Wrong clause reference (to 7.6) …rated in accordance with 6.7, shall be provided. Accepted in principle. Cl 7.6 is Semiconductors, 6.7 is ‘Protection against polarity reversal’ Modify 6.7 to add term supercapacitors in line 1744.

GB-206

2432 8.1.1 1st sentence ed The term “infallible current limiting resistor” is no longer used anywhere else in the standard.

Delete “infallible current-limiting”. Accepted

DE-244

2435 8.1.1 modify reference from 9.9 to 9.8 because it seems 9.8 is the new test replacing 9.9?

modify reference from to 9.8 Accepted

GB- 2435 8.1.1 2nd para ed The test in 9.9 has been replaced with the test in Change reference to 9.8. Accepted

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207 9.8

GB-208

2438 8.1.1 3rd para te “In this case, the failure of only one diode shall be taken into account in the application of 5.2” is not consistent with the use or application of the term “infallible” elsewhere in the standard where it is used to refer to instances where failures are not considered. If this sentence were necessary, then we would need to repeat it in several other places, e.g. 7.6.5.

Delete 2nd sentence of paragraph 3. Not accepted, the failure of one diode may impact the circuit elsewhere.

AU-58

2459 9.1 All Ge This entire clause requires re-construction. Present problems: Under 9.1.2 “Spark test apparatus”, in the second paragraph at line 2483 to 2503, the current text has information on the application of faults. It is not a description of the Spark test apparatus. Under 9.1.3.1, under “Test gas mixtures for safety factor 1,0” the text has line 2509 regarding safety factor of 1,5 Then line 2511 under refers “Test gas mixtures for safety factor 1,0” to the sensitivity check method that should be part of the Spark Test Apparatus at 9.1.2 Similarly, line 2547 is part of the Spark Test Apparatus of 9.1.2 rather than the Spark Ignition energy compliance. Rename 9.1.4 as “Spark Igntion Compliance”

See separate document from AU. Accepted in principle in part. Text has undergone further development and is now mostly in 5.3. Change to 68ms not accepted as the practical no-contact time is less than this. “No-ignition” column in Tables 15 and 16, plus associated text, modified to present an absolute minimum rather than a range.

GB-209

2460 to 2503

9.1.1 & 9.1.2

te Much of these clauses do not relate directly to STA, but are general statements about spark ignition assessment. Placing them here rather than in 5.3 is somewhat convoluted.

Move the following to 5.3: • 9.1.1 2nd para last sentence (“A circuit may

be…”) • 9.1.1 3rd para • 9.1.1 NOTE • 9.1.2 All except the first para Reword for the more general case (see Annex GB-1).

Accepted in principle, text has undergone further development.

DE-245

2470 9.1.1 2nd para Ed/te It should be explained that the Annex A tables can only be used for linear circuits. For non linear circuits Annex H or 60079-25 Annex C (or Ispark) may be used. With the existing text one goes to Annex A and there in a Note (possibly) finds the information

Consider if this is beneficial to add: This in general is the case for circuits with resistive current limitation. For non-linear circuits Annex E or IEC 60079-25 Annex C or Ispark may be used for assessed.

Accepted in part, text has undergone further development. Ispark not included due to lack of information.

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(e.g. Table 1)

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that it is not appropriate the use the tables for that type of circuit.

DE-246

2471 , 2472

9.1.1 3rd para te Why use “alternatively”? Annex A does not consider "let-through energy". So the alternative is using the spark test apparatus, but there is information missing that it may be necessary to modify the circuit in order to guarantee that the let through energy is released every time the circuit is closed or opened by the STA. 3.18.2 defines transient energy, so this term shall be used

Change Text: ”Circuits using controllable semiconductor circuits for limitation of the voltage or current for spark limitation shall be tested for the transient energy in accordance with 9.1.5.3 where it is not practical to ensure that the transient energy is released every time the circuit is closed or opened by the STA.”

Accepted in part, see 5.3.5. STA is not sufficient for controllable semiconductor circuits since a short and open circuit might not be the most onerous fault in the load for let-through energy, neither can STA test for faults in the supply. Text has undergone further development.

FR-30

2471 9.1.1 3rd te Measuring the let-through energy of series or shunt active semiconductor circuits is mandatory in 7.6.5 and 7.6.6. But in 9.1.1, it “may alternatively be tested”

Replace “may alternatively be tested” with “shall be tested”.

Accepted in principle, let-through energy test is mandatory for all semi-conductor controlled limitation under new 5.3.5.

GB-210

2484 9.1.2 2nd para te Normal operation excludes a non-countable fault (see GB comment on “normal operation”).

Re-word per Annex GB-1 Accepted

US-092

2487 9.1.2 Para 2 / 2nd bullet

te The references in this section appear to be incorrect. 6.1.2.2 and 6.1.2.3 are for enclosures, not spacings. This section does not specifically address how countable fault spacings should be treated with respect to insertion of break flash tester.

– at internal connections or across internal creepage distances, clearances, distances through casting compound and distances through solid insulation not conforming to 6.3. 6.1.2.2. or 6.1.2.3. Insertion of the spark test apparatus across countable fault spacings shall be considered a countable fault.

Accepted in part. References removed and these are now just examples. Use of STA is a test, not a countable fault.

BR-15

2488 9.1.2 2nd te Introducing spark ignition apparatus through distances within encapsulation, even if they don’t meet the requirements of clauses 6.1.2.2. or 6.1.2.3 contradicts the 4th paragraph of clause 6.5.1 that excludes the possibility of spark ignition if the encapsulation complies with 6.5.2.1.

Change the paragraph for: “…across internal creepage distances, clearances, distances through casting compound where the encapsulation is not according to 6.5.2.1 and distances through solid insulation not conforming to 6.1.2.2. or 6.1.2.3.”

Accepted in part, references removed and these are now just examples.

AU-59

2490 9.1.2 3 ge Add additional item to list Add the text: The spark test apparatus shall not be used -Within encapsulation used for the protection against spark ignition meeting the requirements of 6.5.2.1


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(e.g. Table 1)

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GB-211

2495 9.1.2 3rd para 4th bullet

te “apart from the exceptions described in 6.4” does not seem to be consistent with “between terminals”. In Ed.6 this referenced 7.6 i) which is about open circuit failures (and is now the 1st sentence of 6.4.1) so also not related to “between terminals”. The need to consider circuit interruptions at terminals is already covered by lines 2483 to 2486.

Delete “apart from the exceptions described in 6.4)” (see Annex GB-1).

Accepted

GB-212

2503 9.1.2 Last bullet point

te “suitably rated” is not clear enough. Replace “are not suitably rated under normal operating conditions” with “during normal operation are operated outside of their manufacturer’s specification.”


AU-60

2511 9.1.3 te With most test and measurement equipment the equipment is specified with a tolerance. For example a voltmeter may have a measurement tolerance of +/-1%. Should the spark test apparatus also have a similar +/- tolerance? We test the sensitivity of the spark test apparatus by applying a nominal +10% (taking tolerances into account this is actually a range of 4% to 17%) however we do not test the lower limit. So the spark test apparatus can be said to have a tolerance of +10% to -100%.

Add a calibration test to confirm the lower limit by applying a spark with -20% energy. Add the following sentence at the end of paragraph 2. The current in this circuit shall be set at the value given in Table 15 minus 20%. If ignition occurs within 440 revolutions of the wire holder with the wire holder at positive polarity, the sensitivity shall not be considered satisfactory.

Accepted in Principle The reduction in Table 15 is on current and not energy. Repeat para 2 of 9.1.3.1 as second para in 9.1.3.2 and add the proposed para to this clause 9.1.3.2 as well (changing the reference from Table 15 to Table 16)

DE-247

2523 -2526

9.1.3.1 NOTE Ed The first sentence in this Note is mandatory Make the first sentence to mandatory text. Accepted in principle, now in 9.1.3.1.

DE-248

2538 9.1.4.1 Te …”most incendive circuit that can arise, … is difficult if not impossible to achieve when producing a sample of an active clamping circuit or a rectangular output. Gains and tolerances of semiconductor parts are not easily adjusted or compensated for, but would attribute to a most incendive circuit. Adjusting resistors or other components to account for this could have other effects on the circuit performance that are not appropriate (slow down or speed up the circuit for example). Limiting the “tolerance” to only RLC parts that can easily be adjusted, is a more realistic and practical

Change first sentence of 9.1.4.1 : … toleranced in accordance with clause 7 for resistors, capacitors and inductors… Add note: Note: When preparing the sample for testing of the most incendive circuit, there is no requirement to find the “worst case” parts for the semiconductor components.

Accepted

AU-61

2553 9.1.4.1 c) Ed Current text on the normal time for recharge is incorrect: “The normal time for recharge is about 20 ms and where this is inadequate it shall be

Revise to: “The normal time for recharge of the capacitor

Accepted in principal Text changed to:

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(e.g. Table 1)

Type of comment


increased by removing one or more of the wires or by slowing the speed of rotation of the spark test apparatus.” The time for recharge depends on the RC of the circuit. So the text of increasing this by “.. removing one or more of the wires..” is incorrect.

must be less than 20 ms using the normal speed of the spark test apparatus and using 4 wires. Where this is inadequate for the recharge time of the capacitor, then the duration between the opening and subsequent shorting of the wire and disc shall be increased by removing one or more of the wires or by slowing the speed of rotation of the spark test apparatus.”

“The normal time for recharge of the capacitor must be less than 20 ms using the normal speed of the spark test apparatus and using 4 wires. Where this is inadequate for the recharge time of the capacitor, then the duration between the opening and subsequent shorting of the wire and disc shall be increased by removing one or more of the wires. Where sufficient charging time cannot be obtained by removing all but one wire, then the speed of rotation of the spark test apparatus may be reduced but not lower than that needed to achieve four time constants.”

DE-249

2554 9.1.4.1 3rd para, c) te WG 4 recommendation is to have a tight tolerance on the speed of rotation, because the sensitivity changes with the speed. With this a reduction of speed is not an acceptable alternative and only removing wires can be allowed.

Delete the reduction of speed option Accepted in principle. See AU-61

AU-62

2569 9.1.4.2 a) Ge This section a) and b) refers to the methods of achieving a safety factor of 1,5. However, this text in a) is equally applicable of safety factor of 1,0 and 1,5: “increase the mains (electrical supply system) voltage to 110 % of the nominal value to allow for mains variations, or set other voltages, for example batteries, power supplies and voltage limiting devices at the maximum value in accordance with Clause 7”

Place this text in 9.1.5.1 Accepted in principle. Reference to 110% of the mains has been replaced with Um. See 5.3.2

GB-213

2576 9.1.4.2 a) 2) ed “an infallible current-limiting resistor” is no longer used

Replace with “a current limiting resistor compliant with 7.3.2”

Accepted

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(e.g. Table 1)

Type of comment


DE-250

2591 9.1.5.1 Para 2 ge Special consideration could include information in IEC 60079-25 Annex C.

Consider reference to IEC 60079-25 Annex C Accepted, see 5.3.4, 5.3.5, 9.3.

US-093

2601 9.1.5.2 a) te Revise item a) to allow evaluation and/or testing to verify the combined effects of capacitance and inductance. In many cases, actual testing is not needed to determine that the interaction between capacitance and inductance in an i.s. circuit maintains the required factor of safety. For example, when under normal and fault conditions, a capacitor will shunt energy from an inductor.

a) tested or evaluated to verify that with the combination of capacitance and inductance maintains the required factor of safety, or

Accepted in principle, b) added to 9.3.

DE-251

2604 9.1.5.2 1) Ed Use : instead of ; after when …curves and tables given in Annex A when: Accepted

AU-63

2612 9.1.5.2 b) 2) Ge Similar requirements are included in both IEC 60079-14 and IEC 60079-25 but written in different ways. This can lead to confusion. The AU committee finds the IEC 60079-14 text easiest to follow.

Change 2) to the following to align with better IEC 60079-14 ed 5 text: Where both the total inductance and capacitance of the circuit (excluding the cable) is greater than 1 % of the allowed values of inductance and capacitance determined by using the relevant ignition curves and tables given in Annex A, the allowed values shall be halved.

Accepted

DE-252

2613 9.1.5.2 2) Ed Plural ‘s’ missing ...curves and tables given… Accepted

FR-31

2621 9.1.5.2 2nd para b) last bullet

te IEC 60079-25:2010 Annex A f) deals with a maximum of 1µF for group IIB, but there is no limitation for group IIA.

Remove the limitation to 1µF for gas group IIA, or transfer this inconsistency to MT 60079-25 for future modification.

Accepted in principle, 79-25 has been modified for a limit of 1uF for IIA

AU-65

2622 9.1.5.2 Second last ed The use of the L/R ratio is also allowed and the lack of reference to it here can be interpreted as requiring the application of Lo.

Add to the end of the paragraph: As an alternative to assessment using the allowed value of inductance, the inductance to resistance ratio may be used. See IEC 60079-14 or IEC 60079-25.

Accept in principle, reworded and removed reference to 79-14

AU-64

2625 9.1.5.2 Last ed Present text has an error. It only refers to lumped capacitance: “Where the application of the above leads to reduced values of Lo and Co for use with lumped capacitance, this shall be included in the manufacturer’s instructions.”

Include lumped inductance as well by revising to: ““Where the application of the above leads to reduced values of Lo and Co for use with lumped inductance and capacitance, this shall be included in the manufacturer’s instructions.”

Accepted

US-094

2627 (2051

9.1.5.3 (7.6.5

ed The calling clauses for 9.1.5.3 use ‘active limitation’ verbiage, but the title of 9.1.5.3 uses

Rename the title of 9.1.5.3 to: Circuits using controllable active semiconductor limitation

Accepted in part “active” (4 places) changed to

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(e.g. Table 1)

Type of comment


2058) 7.6.6) ‘controllable limitation.’ (The terms ‘active limitation’ and ‘controllable semiconductors’ are used interchangeably throughout the standard, which is inconsistent. Consistent verbiage should be used throughout.)

Or Revise the calling clauses to reference controllable semiconductors.

“controllable”

AU-66

2630 9.1.5.3 1 ed Words missing and mistyped “er” Modify the text: Additionally, where intrinsic safety relies on operation of er a controllable semiconductor limitation circuit,

Accept in part, see DE-253

DE-253

2630 9.1.5.3 1st para, 2nd sentence

Ed “er” at the end of line 2630 should possibly become “the”

Change to “the” Accepted

GB-214

2630 9.1.5.3 ed Typo “er” Replace with “the” Accepted

DE-254

2630 9.1.5.3 1st para Ed At the end of the line exchange ‘er’ by ‘the’ ..where intrinsic safety relies on operation of the… Accepted

US-095

2630 9.1.5.3 Par 1 ed Mistake in this sentence with the word “er”: …relies on operation of er circuit,…

Modify the sentence to read: “relies on the operation of the limitation circuit…”

Accepted

US-096

2630 9.1.5.3 ed ‘er’ isn’t a word. Correct the typo. Accepted

FR-32

2630 9.1.5.3 1st ed Typing error Modify the sentence as follows: “on operation of such a circuit”

Accepted in principle, modified to “on the operation of the limitation circuit”

DE-255

2632 9.1.5.3 1st para Ed Plural ‘s’ missing ...shall not exceed the following values for.. Not accepted, there is only one value for each Group

DE-256

2638 9.1.5.3 2nd para Ed/te The acceptance criteria of having the transient energy limited to the given amount of energy can hardly be verified with the STA. The STA shows an ignition if the total energy released in the spark exceeds the limits of ignition. With this it is better to have the information of either using the STA or use the assessment according to 9.1.5.3 in 9.1.1 (see DE comment on 9.1.1)

If comment on 9.1.1 / 3rd para line 2471 is accepted, reduce and modify 2nd para to: “The transient energy released to an intrinsically safe circuit due to dynamic reaction on faults or sudden changes of the load shall be assessed from oscilloscope measurements.”

Accepted in principle, reworded, see 5.3.5

GB-215

2638 - 2640

9.1.5.3 te This sentence describes the applicability of the let-through energy test so should be in 5.3. “Where” is redundant as spark tests can not test for transient energy caused by faults in the supply. This let-through energy could also be used under some circumstances to provide

Move to 5.3, re-word per Annex GB-1 Accepted

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(e.g. Table 1)

Type of comment


output spark limitation.

AU-38

2669 9.3 1 ge The note at line 1762 “A component manufacturer’s specification is sufficient to demonstrate compliance.” provides informative guidance which is contradicted by the normative requirement here “Dielectric strength shall be verified by test.” The text is modified to allow components which are “capable of passing the test” to not need to be verified by test.

Modify the opening paragraph of 9.3: The dielectric strength test shall be one of the following:

Accepted in part, The dielectric strength test shall be either; a) or,b)

GB-216

2670 9.3 a) ed “Either” should be on line above Move “Either” to end of 2669, add colon Accepted

DE-257

2673 9.3 1st para, b) 1st para

ed After 6.8 also specifies the d.c. values, we may delete the 1.4 factor for calculation from a.c. to d.c.

Change text: … ripple at the specified d.c. voltage. Accepted

FR-33

2673 9.3 1st para b) te The accuracy of the dielectric testing voltage is not specified. Other 60079 series standards deal with -0/+5%.

Add a sentence: “The testing voltage accuracy shall be -0/+5%.”

Accepted in principle - modified text to state minimum voltage requirement.

GB-217

2680 9.4 te The critical parameter(s) for intrinsic safety when loosely specified components are used should be document in the manufacturer’s documentation.

Modify text: The most onerous values for the parameters, not necessarily taken from the same sample, obtained from the tests on the 10 samples shall be taken as representative of the component and the critical parameters, i.e. those necessary to ensure intrinsic safety e.g. minimum cold resistance of a fuse, shall be documented as required by IEC 60079-0.

Accept in principle, modified to parameters shall be documented as required by 79-0.

DE-258

2690 9.5.1 1st para Ed Add ‘or supercapacitor’ where necessary Rechargeable cells, batteries or supercapacitors shall be fully charged and then discharged at least twice before any tests are carried out. On the second discharge, or the subsequent one as necessary, the capacity of the cell, battery or supercapacitor shall be confirmed as being within its manufacturer’s specification to ensure that tests can be carried out on a fully charged cell, battery or supercapacitor, which is within its manufacturer’s specification.

Accepted

GB-218

2695 9.5.1 te The 3 mΩ test is only acceptable if all of the energy is dissipated. See IECEx DS – This is not currently addressed by the draft standard.

Refer to IEC TC31 WG37 for input or use the IECEx DS to provide the necessary text.

Accept – Add the following to 9.5.1

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(e.g. Table 1)

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The cell current and voltage shall be continuous during the discharge. There shall be no sudden drop of current and voltage to zero.

GB-219

2699 9.5.2 /9.5.3 te Are the tests conducted at the service temperature or normal room ambient?

Refer to IEC TC31 WG37 for input. Accept – Add to 9.5.1 General The tests for Electrolyte leakage in 9.5.2 and Surface Temperature in 9.5.3 b) shall be conducted as follows; a) On 3 test samples at the laboratory ambient temperature, b) On 3 test samples at the maximum service temperature, and c) On 3 test samples at a temperature between laboratory ambient and the maximum service temperature. Following these tests a further 7 test samples shall be tested at the ambient temperature from a), b) or c) above which results in the maximum temperature of the cell surface when referenced to the Ta of the equipment.

AU-67

2717 9.5.2 5 ed Paragraphs 4 and 5 should be merged together and reworded to prevent misinterpretation

Modify the text: Where encapsulation has been applied to achieve conformance to 7.11.2, examination of the cell at the end of the test shall show no damage which would invalidate conformance with 7.11.2. As an alternative to the above, Alternatively, the compatibility of electrolyte with the encapsulation

Accepted

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(e.g. Table 1)

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may be tested by applying the electrolyte directly to a sample of encapsulant. The sample thickness and applied electrolyte volume shall be representative of the application. After at least 12 hours, there shall be no observable damage to the encapsulant which would invalidate conformance with 7.11.2.

GB-220

2720 9.5.3 te Any changes to cell per UN spec need re-testing?

Refer to IEC TC31 WG37 for input. Not accepted Ideally retesting is required if the type of change that might be considered to differ from the tested type, such that it might lead to failure of any of the test results. Section 38.3.2.2 of the UN Manual of Test and Criteria for Transport of Dangerous Goods defines changes to the cell that require re-testing. The same content is also considered for the next edition of IEC 60086-4 (Ed. 5, see 35/1379/CD).

GB-221

2720 9.5.3 te IEC 62133:2017 includes a new structural integrity test.

Refer to IEC TC31 WG37 for input. Not accepted WG 37 considers this is a manufacturer test not a user test and this should not be incorporated in 60079-11.

GB-222

2720 9.5.3 te Regarding, “If the internal current limiting devices protect against internal shorts then these devices need not be removed. However, such devices shall only be considered for Level of Protection “ib”.” Only the separator provides current limitation, it is not possible to manufacturer a battery without this separator and have a working battery. The CID or PTC do not limit the temperature.

Refer to IEC TC31 WG37 for input. Not accepted State-of-the-art lithium cells contain so-called “shut-down separators” that can limit the current, also in case of an internal short circuit. The use of these separators has made lithium cells much safer. Such cells should therefore also be allowed for use in “ia” if they pass the 3 mΩ

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(e.g. Table 1)

Type of comment


short-circuit test. Modify 9.5.3 as follows, remove the sentences “If the internal current limiting devices protect against internal shorts then these devices need not be removed. However, such devices shall only be considered for Level of Protection “ib”.”

GB-223

2720 9.5.3 ed Separate this section in to 9.5.3.1 – General, 9.5.3.2 – Leakage & 9.5.3.3 Temperature.

Separate this section in to 9.5.3.1 – General, 9.5.3.2 – Leakage & 9.5.3.3 Temperature.

Not accepted, insufficient detail.

SE-09

2731-2734

9.5.3 Para a) Te The standard requires now encapsulation of the circuit between a current-limiting device and the battery/cell, if such a device is included in the circuit. This means that replaceable batteries/cells cannot be used as they adhere to such encapsulation, which seems to be wrong. Encapsulation should not be required, if the requirements for infallible distances are fulfilled.

Amend the first sentence in para 1) to read: “Spark ignition assessment or testing shall be carried out at the cell or battery external terminals, except where a current-limiting device is included and the circuit between this device and the cell or battery has infallible distances to other circuits.”

Accepted in principle, modified verbiage "maintains infallible separations or is encapsulated"...

GB-224

2732 9.5.3 te The internal current-limiting devices do not always need to be short-circuited, but can be disabled, by for example, filling the gap above the vent with an epoxy resin (possible hazard), or approaching the manufacturer to have the vent replaced with a solid disc. Note 1: Current limiting by PTC or CID (current interrupting device) Note 2: ….?

Refer to IEC TC31 WG37 for input. Not accepted Change the text in 9.5.3 as follows: For “ia” and “ib” the test shall be carried out with internal current-limiting devices removed or bypassed using 10 cells. The 10 samples having the internal current-limiting devices removed or bypassed shall be obtained from the cell/battery manufacturer together with any special instructions or precautions necessary for safe use and testing of the samples.

FR-34

2738 9.5.3 2nd para of a)

te The spark risk doesn’t need to be assessed if a cell has an open-circuit voltage of less than 4.5V (and could not be changed in explosive

Limit the maximum current allowed to a certain threshold?

Not accepted - The avoidance of spark ignition assessment applies to the

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(e.g. Table 1)

Type of comment


atmosphere). This relaxation is often used in assessment, because of non-infallible distances between polarities on the cell case. But nowadays, short-circuit current of a single Li-Ion cell could reach ~300A. With such a high short-circuit current, even a parasitic inductance as low as 0.9 nH is enough to store 40µJ (energy allowed in inductance for IIC in figure A.4 of ed6). Shall this “relaxation” be kept as it?

(for example, using ignition curves from PTB or CERCHAR for a voltage of 4.5V ? - but it would be very conservative: only 16A for IIC)

cell only. The intrinsic safety aspects of the circuit still need to apply, including any attached inductance. Hence, if there is a very high current, the presence of even a small inductor would require spark ignition assessment. An absolute limit is therefore not required.

DE-259

2745 9.5.3 te Cells may not necessarily exhibit the highest surface temperatures when tested at lab ambient temperatures to the maximum specified ambient temperature's. Some cells may have higher surface temperatures when the test is conducted at 0°C and below.

The specified number of cells or batteries shall be tested across the minimum and maximum service temperature and the maximum value obtained shall be used directly in the temperature class assessment…

Not accepted, WG 37 did not consider that batteries need testing at a lower temperature. Further consideration is being given to developing the temperatures for this test.

GB-225

2756 9.5.3 b) 3rd sentence

ed Missing “Levels of Protection” is not consistent with the rest of the text.


GB-226

2770 9.5.3 c) ed Missing “Levels of Protection” is not consistent with the rest of the text.


IT-22 2770 9.5.3 c) ed Indent c) is not necessary. The text should belong to item b).

Remove c) and leave the text as it is, under item b)

Accepted

DE-260

2772 9.5.4 Ge With the new definitions of ‘battery container’, battery case’ and ‘battery compartment’ in IEC 60079-0, this standard should be edited to use the correct terminology. In most cases ‘battery compartment’ would be the correct exchange for ‘battery container’

9.5.4 Battery compartment pressure test Not accepted, container is the verbiage used in the calling clause and MT feels this is the more correct terminology. Both could be correct; a more detailed proposal should be submitted.

SE-10

2772 9.5.4 Title Ed The title “Battery container pressure tests” may be misunderstood as requiring pressure tests of battery containers in general, instead of understood as requiring pressure tests of certain sealed battery containers according to 7.11.3.

Amend the title to read: “Pressure tests of sealed battery containers”

Not accepted, scope of test is in the calling clause.

SE-11

2773-2785

9.5.4 Ed Clarify the first sentence “Five…samples”. It would facilitate the understanding of the requirement, if examples of typical measures to attain the required venting are specified.

Amend the first sentence to read: “Five samples of the sealed battery container shall be subjected to a pressure test to determine at which pressure venting occurs”. Clarify the requirements, by providing examples of

Accepted in part, sealed not accepted, see SE-10, no proposal provided for the example recommendation.

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(e.g. Table 1)

Type of comment


typical venting measures for sealed battery containers, e.g. in a note.

GB-227

2810 9.7 1st sentence ed The first sentence is too long. Use of the imperative is not consistent.

Modify text: Measure both The following shall be measured: - the capacitance of the device; - the voltage appearing across itthe device

when any part of the intrinsically safe apparatus which is accessible in service is impact tested in accordance with the “high” column of the table for Ttests for resistance to impact table in IEC 60079-0. This test shall be carried out at (20 ± 10) °C using the test apparatus in IEC 60079-0.

Accepted

AU-68

2814 9.7 1 Te During the piezoelectric device tests, damage to the equipment is possible, making two tests on the one sample impossible. It is also possible to achieve higher voltages at lower impact energies. The proposed change will also allow some semblance of uniformity with MSHA Standards, which requires one impact each on 3 samples.

Revise to: Measure both the capacitance of the device and also the voltage appearing across it when any part of the intrinsically safe apparatus which is accessible in service is impacted at the energy which produces the highest voltage up to the “high” column of the Tests for resistance to impact table in IEC 60079-0 carried out at (20 ± 10) °C using the test apparatus in IEC 60079-0. For the value of voltage, the higher figure of two tests shall be used. The tests should be completed on the same sample; however, it may suffer damage during the test and further samples may be required. Note: The highest voltage might be at a lower impact energy.

Accept in part. There is support for the concept however, not enough information to determine highest voltage. Too much ambiguity on what to do with sample, once it has been damaged during testing. How much damage is unacceptable?

DE-261

2820 -2823

9.7 ed Sort order is usual IIC, IIA,.I IIB values should apply for Group III as well

Change sort order to usual one … Add in line 2822: and Group III apparatus

Accepted in part. Sort order in the rest of the standard is IIA, IIB, IIC. 9.1.5.3 modified instead, that is not consistent. Group III added to Group IIB

DE-262

2832 to 2876 and 2877 to 2903

9.8 and 9.9 ed Text of 9.8 was intended to replace what is in 9.9 now. All references from the calling clauses still go to 9.9 and not to 9.8.

If new text in 9.8 is accepted to replace what is 9.9 now, adjust all references calling 9.9 to 9.8.

Accepted

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(e.g. Table 1)

Type of comment


DE-263

2832 ff

9.8 te Test regarding chapter 9.8 is not practical for semiconductor shunt voltage limiters, because in front of a voltage limiting semiconductor there is no infallible resistance. This would have an impact on blowing the fuse. Taking into account the cold resistance of a fuse is also not practical, because in a µController power supply the fuses only have a few mOhm.

Add an alternative at the end of line2849: Alternatively test the protected component in its circuit at ten samples and compare the primary values of the protected component before (3) and after the test (5). Or at the end in front of line 2873: Alternatively for a circuit on the secondary side of a transformer according to 7.7.2. Test the protected component in its circuit at ten samples and compare the primary values of the protected component before (3) and after the test (5).


AU-69

2833 9.8 1 te The introduction paragraph is not clear, reword for clarity.

Modify the text: Where a component on which intrinsic safety depends is protected by current limitation, the following tests are used to demonstrate the component can withstand the effects of transients during the operating time of the current limitation. Examples of components which have an operating time when providing protection to other components are fuses and semiconductors.

Accepted

GB-228

2836 9.8 2nd para te This is not part of the test. Delete if GB comment on line 1840 to clarify transient ratings of resistors is accepted, otherwise move to 7.3.2.

Accepted and moved to 7.3.2

DE-264

2838 9.8 3rd para, ed 9.8 is the test, so the calling clause(s) (obviously missing) should state that the test shall be applied in case compliance cannot be shown from the datasheet.

Identify the calling clause(s) and move (modified) sentence to that clause(s).

Accepted

DE-265

2842 9.8 3rd para, 1) 1st dot

ed/te Why not say “cold resistance of the fuse according to 7.3.2” instead of creating a different definition (at minimum ambient versus at service temperature)

change to “cold resistance of the fuse in accordance with 7.3.2

Accepted

GB-229

2861 9.8 EXAMPLE ed The example relates only to 3) Indent to align with “The primary value” Accepted

GB-230

2861, 2875

9.8 EXAMPLE ed There are two examples Number the examples Accepted

DE-266

2865 , 2866

9.8 3rd para, 1) 1st dot

ed/te Vague requirement! Under which conditions additional pulses are required?

Delete or put in a clear requirement. Accepted, modified to read "for resettable current limiting circuits, the number of pulses should be greater than the designed

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(e.g. Table 1)

Type of comment


maximum demand."

GB-231

2867 9.8 5) te The primary value should be measured at the same current as before (per Ed. 6 10.8 5th para)

Add “at the same current as 3)” after “re-measured”

Accepted

GB-232

2875 9.8 EXAMPLE ed Inconsistent use of “Zener” Add “diode” after second “Zener” Accepted

DE-267

2875 -2876

9.8 EXAMPLE te Would not be even true for same type diode. Z-diodes behaviour depends on Zener voltage, too – see other diode specifications

Delete example – or state: Testing a 12 V Zener diode for a fuse current is considered to demonstrate the suitability of a 5.2 V Zener diode of the same type at the same fuse current.

Accepted, 2nd proposal.

GB-233

2877 - 2903

9.9 te 9.8 is a re-write of this clause to make it easier to follow and more generic.

Delete clause. Accepted

DE-268

2887 ff

9.9 modify reference from 9.9 to 9.8 because it seems 9.8 is the new test replacing 9.9?

delete chapter 9.9 Accepted

DE-269

2913 -2915

9.11 te Does this vague text require conducting the dielectric strength test at the temperature reached in the type test before or is the requirement only to do it after the materials were stressed during the type test. See DE comment on 3024 / 9.12.2.3 where it is clearly advised to let the test samples cool down to 25°C for the dielectric strength test.

consider what shall be required and put wording clear using similar requirements for both transformers and optical couplers.

Accepted in principle, 25C with tolerance specified.

DE-270

2913 -2915

9.11 te Why is there no type test against the separated core or screen? Routine tests in 10.2 are against core and screen.

consider if type test for core or screen should be required

Not accepted. Routine tests are sufficient.

IT-23 2936 9.11.1.2 ed/te These transformers may be confused with those in 9.11.2 as they are not mains transformers.

Change heading to: “Transformers in DC/DC converter circuits”

Not accepted, text in clause is clear.

DE-271

2937 to 2940

9.11.1.2 1st and 2nd

para ed The content of both para belong together and

should form one para. Make both paras become one. Accepted

DE-272

2947 -2950

9.11.1.3 1st para Te This acceptance criteria has been questioned since many years. A draft decision sheet was raised on that by PTB in 2010 and the matter was discussed at MT60079-11 in 2011 in Seattle but was hold back to the development of the next edition, which is now the case.

See Annex A for a copy of the draft decision sheet from 2010. This needs to be discussed by the MT.

Noted specific proposal required.

GB-234

2962 9.11.2 te These lines relate to routine tests which are addressed in 10.2

Delete: “If such transformers are connected on both sides

Accepted

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(e.g. Table 1)

Type of comment


to intrinsically safe circuits, then a reduced voltage of 500 V between the primary winding and the secondary winding shall be applied for a routine test, as given in 10.2”

DE-273

2965 to 2968

9.11.2 3rd and 4th para

te The content of both para belong together and should form one para. Knowing that generally these type of transformers are used in DC/DC converters, it should be made clear that the requirement only applies to such cases.

Make both paras become one. Change to: Where such transformers are use in DC/DC converters, transformers shall be tested …

Accepted in part. Transformers may be used in many circuits.

DE-274

2982 9.11.3 Last para Ed Use the correct term from IEC 60085 …the temperature of the thermal class in accordance…

Accepted

DE-275

3008 9.12.2.2 ed State that these 5 samples are “new” – or state at the beginning that 10 samples required – 5 for test 9.12.2.1 and 5 for 9.12.2.2

Test shall be conduct on five samples (not used for test 9.12.2.1

Accepted in principle Addressed by change to 9.12.2 specifying the number of parts for each test Delete 2996 and 3008

DE-276

3024 9.12.2.3 2nd para te While the dielectric strength test for transformers is often required by agencies (vague text of 9.11) to be done at the maximum temperature reached in the type test, it is a contradiction to clearly require the couplers to cool down to 25°C.

Consider with DE comment on 2913 / 9.11, if the transformer type test shall also be conducted at 25°C.

Comment not accepted Should be dealt with by a transformer task group Recommend looking at whether transformer test can also be done at 25C

DE-277

3029 9.12.2.3 Last para Ed For the dielectric strength test in 9.3 the acceptance criteria is 5 mA r.m.s. The same should be used here.

…current shall not exceed 5 mA r.m.s.. Accepted

DE-278

3030 -3052

9.12.3 Ge This clause is only for optical isolators, Use in all subclauses the term ‘optical isolator’ should instead of ‘isolator’.

Accepted

DE-279

3033 9.12.3.1 1st para Ed/te After the “limited short circuit test is taken out, it should not be mentioned here.

Delete: “and if applicable to the current limited short circuit test described below”

Accepted

AU-70

3033 9.12.3.1 1 Ed Present text refers to “current limited short circuit current test”, but this text is based on the previous Edition that had two tests within 9.12. Present text: “Optical isolators shall be subjected to a dielectric strength test, followed by a short-

Revise to: “Isolators shall be subjected to a dielectric strength test, followed by a short-circuit current test, followed by a dielectric strength test.”

Accept in principle Covered by 9.12 title scope exclusive to optical isolators

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(e.g. Table 1)

Type of comment


circuit current test and if applicable to the current limited short-circuit current test described below, followed by a dielectric strength test.” Additionally, reference to optical isolators should be made generic.

DE-280

3035 -3039

9.12.3.2 Te Even for this Pre-test the test parameter duration and acceptance criteria must be given.

Prior to the short-circuit current tests, the samples of the isolator shall be capable of withstanding without breakdown a dielectric strength test of 4 +5%0 kV r.m.s. applied between intrinsically safe and non-intrinsically safe terminals. The test voltage shall be increased steadily within a period of not less than 10 s until it reaches the prescribed value, and it shall then be maintained for at least 60 s. During this test, there shall be no breakdown and the leakage current shall not exceed 5 mA r.m.s...

Accepted in principle Rewritten to reference 9.3B with explicit limit. Lower limit because it is a component not a system

DE-281

3036 9.12.3.2 1st para ed This para would better fit in 9.12.3.1 and as these three new samples will be used in all three test procedures “test” should be plural.

Move para to 9.12.3.1 to become 1st para Three new samples shall be used for these tests.

Accepted in principle Addressed by modifying text in 9.12.3.1

IT-24 3038 9.12.3.2 te “… a dielectric strength test of 4+5%0 kV rms

applied …” Dielectric or isolation test? No time is specified for the test. Clarify.

Accepted in principle See DE-281

DE-282

3040 -3046

9.12.3.3 Te In the case that Um is only applied as a ‘common mode’ voltage, the application of the nominal operating voltage as open circuit voltage of the test circuit would be sufficient.

Add this alternative as test procedure in case the non-IS side is connected to a SELV or PELV system.

Not accepted However, the TG recommends modification to make it consistent with other changes.

DE-283

3041 9.12.3.3 Ed It should be clear that the same samples, used in the previous test must be taken.

The three samples of the isolator applied to the pre-test dielectric of 9.12.3.2 shall be subjected…

Accepted in Principle Addressed in DE-281

DE-284

3048 9.12.3.4 ed The samples of test 9.12.3.3 shall be used – is missing

Add: Each sample from 9.12.3.3 shall….” Accepted in Principle Addressed in DE-281

DE-285

3048 9.12.3.4 Te It is not specified, how the voltage shall be applied: with a switch or slowly increasing? Normally, we have a ramp, where the voltage is increased over 10 seconds.

Add as a 2nd para: The test voltage shall be increased steadily within a period of not less than 10 s until it reaches the prescribed value, and it shall then be maintained for at least 60 s.

Accepted in principle Rewritten to reference 9.3 b) with explicit limit. Lower limit because it is a component not a system

DE-286

3051 9.12.3.4 ed Precise what is meant explode The isolators shall not explode or crack or catch fire throughout”….

Accepted in Principle Addressed in DE-285 Substitute Burst for

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(e.g. Table 1)

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Explode

DE-287

3051 9.12.3.4 1st para Ed This clause describes only one test. Use the singular for test or make clear that this criteria shall apply for all three tests in 9.12.3.2 to 9.12.3.4

Consider and modify wording Accepted in principle, clause reworded. Addressed in change to 9.12.3.3. Se DE-282

DE-288

3052 9.12.3.4 Last para Te Why 1 mA? In all other dielectric strength tests 5 mA are sufficient. This test might require a different test equipment, without any need.

Change to: …the current shall not exceed 5 mA r.m.s. during the dielectric strength test.

Accepted in Principle See DE-285

MT 60079-11

9.12.1 Te The following tests shall be performed if optical isolators are used to provide isolation between intrinsically safe circuits and non-intrinsically safe circuits and are not adequately protected against overload by external protection components (see 7.9.2).

The following tests shall be performed as required by 7.9.3 d) for optical isolators used to provide isolation between intrinsically safe circuits and non-intrinsically safe circuits

Accepted

MT 60079-11

9.12.2 ed 9.12.2 has a hanging paragraph which is not permitted by DIR-2 22.3.3.

9.12.2.1 General Accepted

MT 60079-11

9.12.2 Te if there are protective components to consider this protective components for this test

until either: a) the receiver semiconductor is damaged. This will terminate or drastically reduce the power dissipation. b) the power at the receiver semiconductor reaches the point to which it is limited by protective components or assemblies that form part of the circuit. The maximum surface temperature of the receiver side just before the damage of the receiver occurs or the temperature under the condition of b) shall be recorded for each sample together with the ambient temperature.

Accepted

MT 60079-11

9.12.3 Te if there are protective components to consider this protective components for this test

until either: a) the receiver semiconductor is damaged. This will terminate or drastically reduce the power dissipation. b) the power at the transmitter semiconductor reaches the point to which it is limited by protective components or assemblies that form part of the circuit The maximum surface temperature of the transmitter side just before the damage of the

Accepted

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(e.g. Table 1)

Type of comment


transmitter occurs or the temperature under the condition of b) shall be recorded for each sample Ttogether with the ambient temperature.

MT 60079-11

9.xx (new after 9.12)

Te Add test for parasitic leakage 9.13 Isolator Operational Tests 9.13.1 Differential Leakage Current Three samples of a signal isolator that has power and ground terminals in the signal output side shall be subjected to a differential leakage test. The signal input side of the signal isolator shall be operated at the nominal operating voltage for the application. Input signals of logic high, logic low and toggling maximum data rate at 50% duty factor shall be applied to all inputs on the powered side of the signal isolator. The voltage generated on the receiving side shall remain less than 0.5V into a 10kohm load for each test condition.

Accepted

CH-41

3053 - 3057

9.13 te Taking the dielectric strength test as an example, it seems to be recommended to describe in clause 9 only the test conditions, but not the requirement, especially when the test might be used for different purposes with different parameters. Example: The test might also be used to prove thermal ignition compliance.

Move the safety factor to the location it is related to,Table 8 in clause 6.4.2.4.

Not accepted. As written, this test is very specific to circuit board connections.

US-097

3054 9.13 1 te Revise to indicate that the testing should be conducted at the maximum rated ambient temperature.

The current carrying capacity of the connection shall be tested for at least 1 h at the maximum rated ambient temperature with a current of 1,5 times the maximum continuous current which can flow in the connection under normal and fault condition. The application of this test current should not cause the connection to fail to open-circuit or to be separated from its substrate at any point.

Accepted. Revise as indicated.

DE-289

3069 10.1.2 modify reference from 9.9 to 9.8 because it seems 9.8 is the new test replacing 9.9?

modify reference to 9.8 Accepted

GB-235

3069 10.1.2 b) ed The test in 9.9 has been replaced with the test in 9.8


CH-42

3070 - 3085

10.2 te Seen the new approaches for signal couplers, it seems to be recommended to review the routine verification for transformers, because

Noted, no proposed change.

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(e.g. Table 1)

Type of comment


transformers are only one specific construction in a variety of galvanic isolators.

GB-236

3070 10.2 te What test should be used as a default if there is no relevant industrial standard – Use the routine test voltages for ‘ia’ and ‘ib’ XFMRs?

Add “Where no relevant industrial standard exists the routine tests specified for ‘ia’ and ‘ib’ transformers shall be used.”

Accepted

IT-25 3077 10.2 ed “…a period of at least 60 s.” Is not in line with other part of the text.

Change to: “…a period of at least (65 ± 5) s.” Not accepted. The term "at least" provides a tolerance.

DE-290

3085 10.2 Table 17 Routine tests with DC Voltage according to 6.8 Define DC Voltages for routine tests Accepted - added a statement at the bottom of the table

CH-43

3086 – 3100

10.3 te The clause does not describe a design requirement for the product, but one possible quality assurance measurement for the production process and should be transferred to IEC 80079-34 for discussion. For the different processes named, there are other process controlling means available and required.

Delete clause in IEC 60079-11 and move it to MT 80079-34 for discussion.

Not accepted. Inspection is a requirement, which will be verified in 79-34. Changed title from Visual Inspection to Inspection to permit digital inspections, etc.

DE-291

3087 10.3 1st para Ed The term “i” equipment is not defined. Use ‘apparatus’ instead

Each apparatus, which uses moulding… Accepted in part, “Apparatus that”

US-098

3097 10.3 te Regarding entrapped air and pin holes, these are already permitted in the encapsulation section.

Revise to read “entrapped air and pin holes other than what is permitted in section ..”

Accept in principle “entrapped air and pin holes other than free space as permitted in 6.5.7”

BR-16

- 11.1 - te Marking of non-hazardous area accessories should be included in the scope of this standard given that these parts may be assessed per requirements of this standard. Non-hazardous area accessories, when assessed according to this standard should include in the marking at least the certificate number and the input and output parameters to indicate compliance to this standard and inform the assessed parameters

Include: “Non-hazardous area accessories assessed or tested for limitation of parameters for the infallible components within the intrinsically safe apparatus shall be marked with the certificate number and the relevant parameters, i.e. maximum input voltage used when assessing and testing the limiting components.”


DE-292

3110 11.1 NOTE 1 Ed This Note contains mandatory text. ‘Should’ is not allowed in a Note. A user must read the instructions to install and maintain an apparatus. Very often only limited space on labels and after installation no longer visible.

Delete Note 1 or revise to read as follows: The marking of relevant parameters is optional if not required elsewhere in the standard e.g. in 6.2.5 for Um, because these are available in the instructions.

Accept in principle, see GB-237

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(e.g. Table 1)

Type of comment


GB-237

3110 11.1 NOTE 1 te This note is a recommendation so should not be a note. It is in a strange order.

Make normative text. Modify: “All relevant intrinsic safety parameters, for example Um, Li, Ci, Lo, Co, should be marked, for example Um, Li, Ci, Lo, Co, wherever practicable.”

Accept in principle, examples deleted, reworded.

CH-44

3133 – 3135

11.1 te There are different reasons for excluding the entity parameters from the nameplate. Naming only one might question the handling of others.

Change to Entity parameters need not be marked

- for FISCO devices - in case of unsufficient space on the

nameplate

Not Accepted. This is covered under the statement of "where practicable."

US-099

3151 11.3 Table 18 ed Reference to 7.11.9 is hanging out in the wind on a line of its own. It is lonely and wants to be scooched up with its friend on line c.

Move reference to 7.11.9 to the same box as item C, 6.2.5

Accepted, infallible connection applied.

DE-293

3158 11.4 b) Ed In this example the IS apparatus is passive and will only be supplied by IS circuit.

Intrinsically safe apparatus supplied by other IS circuits

Accepted

DE-294

3171 11.4 Figure f) Ed Li Li Accepted

IT-26 3178 12 1) 2)

ed “… if applicable…” A power source shall always have Co and Lo while, power receiver could not have the Ci and Li as parameter.

Delete: “…and, if applicable, …” Put in item 2) “….Ui, Ii, Pi, and if applicable Ci, Li and the Li/Ri ratio.

Accept in principle, removed all "if applicable" statements, since this is already stated in the first paragraph.

CH-45

3181 12 b) ed 12 b) is an overall umbrella for the other requirements listed

Move requirements in a), c), d), e), f), and g) to 12 b) as examples.

Not accepted, special requirements are considered additional items other than those in the list.

DE-295

3185 12 c) Ed When Um is applied to an associated apparatus, it is applied to the non-intrinsically safe circuit(s) only. Delete “or associated apparatus”.

the maximum value of Um which may be applied to terminals of non-intrinsically safe circuits.

Accepted in part, “non-intrinsically safe connection facilities”.

DE-296

3186 12 d) Ed Use the defined term “Specific Conditions of Use” Delete the examples, because they are not representative for the ‘X’ markings according to this standard.

any Specific Conditions of Use which are assumed in determining intrinsic safety;

Accepted in principle, deleted "specific" so these are not confused with 'X' conditions.

DE-297

3189 12 e) Ed This requirement is already contained under d) because it requires the ‘X’ marking.

Delete e) Accepted X condition included in 79-0

CH-46

3193 12 h) te The use of Table 6 and Table 7 does not necessarily imply Special Conditions of Use related to pollution degree and overvoltage category. Overvoltage category does not seem to

Delete requirement stated in 12 h) or move it to 12 b) by adding the words “when required”.

Accepted in principle, see JP-23

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(e.g. Table 1)

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require additional safety measures at all. Only when the construction requires special limitations for installation and use, these should be stated in the documentation. Requirement 12 b) seems to be adequate to address this purpose and makes 12 h) redundant.

DE-298

3193 12 h) Ed This requirement does not apply when an enclosure has been chosen, that provides the pollution degree 2 already. Clause 6.1.2.3 defines, under which circumstances an ‘X’ marking is required. This is then covered under d)

Delete h) Accepted in principle, see JP-23

JP-23 3193 3194

12 h) te “the ambient pollution degree” does not match the definition of pollution degree. Environmental conditions are addressed in 12 f) and does not have to be mentioned here.

Remove “the ambient pollution degree” from 12 h).

Accepted

BR-17

- A.1 - te Another pillar of intrinsically safe evaluation is the infallible connections, it should be provided on this clause as there are several solutions where infallible connections are applied to avoid the sparking condition to arise or when components cannot be disconnected as it would impair the intrinsic safety.

Include: “d) the circuit shall include adequate connections where the circuit carry spark ignitable parameters.”

Not Accepted - text has been moved to section 9.2

DE-299

3197 A Ge The references to clauses, tables and figures of Annex A are not set properly.

e.g in 3205 it must be clause 4 not 3.15 Accepted

GB-238

3204 A.1 a) te Annex A forms the basis for the application of the standard and is substantially unchanged since the 4th edition of the standard despite major changes being introduce to the main body of the standard

Rewrite Annex A considering all the changes made in the 5th, 6th and draft 7th editions.

Accept in principle, moved much of Annex A to the body of the standard. See draft.

US-100

3204 A.1 a) te Incorrect reference to Clause 10. The reference should be to 9.1.

…ore assessed as required by Clause 10 9.1 for the specified …

Not accepted. Reference not required once text was moved/merged from A1 to clause 5. Moved A.1 to 5.1

DE-300

3206 A.1 a) Ed Delete “electrical” …of apparatus; Accepted

DE-301

3207 A.1 b) Ed This is not a criterion of an IS circuit but of the entire IS apparatus.

Remove this bullet point from the listing and make it an independent paragraph below the listing.

Accept and moved to section 5.1

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(e.g. Table 1)

Type of comment


NOTE 2 must then be related to this new para as well.

DE-302

3212 -3219

A.1 Note 1, 2 ,3 Ed The Notes contain requirements “may be” and “can” which is not allowed in Notes.

Revise the Notes to be statement of facts. Accept in principle. Remove permissive text from NOTE 1. Removed “at the boundary for ignition” as the point of the annex is to assess this boundary. Remove note 2 and revise the body of the new item b): “…other circuits by the provision of adequate creepage distance…[balance of note]” Moved to section 5.1.

GB-239

3212 - 3219

A.1 Notes te The notes contain permission so should not be notes.

Make all three notes normative text. Accept in principle – See resolutions of DE-302.

US-101

3212 A.1 Notes 1, 2 ed These notes contain permissive text and likely do not meet IEC requirements for notes.

Revise the notes or convert to body text. Accept in principle – See resolutions of DE-302.

GB-240

3223 A.2 1st para te Specifying fault conditions would exclude Annex A being used for “ic”.

Replace “fault conditions in accordance with 5.2” with “under the conditions specified in 5.2”.

Accept in principle and moved to section 9.2

GB-241

3226 A.2 1st bullet te Much of intrinsic safety fault analysis is not practical, e.g. semiconductors failing to a perfect short circuit.

Replace “worst practical” with “most onerous” Accepted in principle – Revised to “ the appropriate conditions specified in 5.2 shall be taken into account.” Moved to 9.2.1

DE-303

3235 -3245

A.2 Note Ed This Note contains a lot of requirements, restrictions and permissions.

Needs to be discussed and re-written. Maybe as normative text.

Accepted in principle. Note deleted, requirements for non-linear supplies are now contained in 5.3.5.

GB-242

3269 A.3 NOTE 2 te This note is permission / recommendation Make normative text. Remove number from NOTE 1.

Accept in principle, changed “may’ to “can” and emphasised use of STA. Moved text to 9.2.2

GB-243

3285 A.4 1) iii) te Resistors are no longer referred to as infallible. 7.3.2 is a subclause, not a clause. The link is missing.

Replace “to the requirements for infallibility (see Clause 7.3.2)” with “to 7.3.2” Add link to 7.3.2.

Accepted. Also fix section numbering in this section and move to section 9.2.2.1

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(e.g. Table 1)

Type of comment


DE-304

3293 A.4 a)1)iv) Ed The unit is missing after 73,3 …increased to 1,5 x 73,3 mA = 110 mA. Accepted

DE-305

3301 A.4 a)2)i) Ed The units are missing. …, the maximum possible current in the load is 22 V/(300 Ω + 1 100 Ω) = 15,7 mA.

Accepted

DE-306

3305 A.4 a)2)ii) Ed The unit is missing after 15,7. …increased to 1,5 x 15,7 mA = 23,6 mA. Accepted

DE-307

3309 A.4 NOTE 1 Ed This Note contains requirements Change to paragraph in the standard text. Accept in principle. Promote note text to body, delete “significantly”, reference “A.6 and A.6 may be used. Renumber note 2. Move to 9.2.2.1

GB-244

3309 -3314

A.4 Notes 1 & 2 ed These notes apply to a) (per Ed.6) Indent to make applicable to all of a) Not accepted. Note 1 promoted to body text in 2)iii). Note 2 applies only to 2)iii) – indentations fixed to reflect this.

DE-308

3310 -3314

A.4 NOTE 2 Ed This Note contains requirements Change to paragraph in the standard text. Accept. Modified to read: “NOTE 1 The above This assessment assumes that the inductor is air-cored which reflects a worst-case ignition hazard. If the inductor is not air-cored, spark ignition testing may be used in order to establish whether the inductor is intrinsically safe. such assessments can be regarded as only approximate and it is necessary to test the circuit with the spark-test apparatus (Annex B) in order to establish whether or not it is intrinsically safe. In practice, if the assessment is based on a measured inductance value, the actual minimum igniting current is usually, although not always, greater than the assessed value.”

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(e.g. Table 1)

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DE-309

3337 -3344

A.4 NOTE 3 Ed This Note is more an Example. Change from NOTE to EXAMPLE and revise the text to be a statement of fact.

Accept in principle. Change “may” to “can”. Other minor editorial revisions made including adding the unit (V) to 26 and revising “as regards” to “regarding”.

DE-310

3345 -3352

A.4 NOTE 4 Te This Note contains requirements that have been often ignored by certification bodies. The results from the SC31G WG4 meeting in Frankfurt from October 2016 should be taken into consideration. (Report see Annex B)

Should be discussed by the MT or assigned to WG4 or a TG to create a proposal

Accepted in principle, Note deleted and text addressing the issue added to 9.2.3.

AU-71

3359 Annex A Fig A.2 Ge Since the spark test apparatus is limited to 300V, how are these curves validated above 300V? Fig A.1 on resistive circuits also stops at 300V.

Limit the max voltage in Fig A.2 to 300V. Adjust graph accordingly.

Not accepted – adjusting the graph is a non-trivial task since access to the raw data used to generate the curves is unavailable. The validation of the curves was done as part of the research in the 1960’s that developed the various curves in 60079-11. Most of the other data was also obtained at the same time (Capacitance figures have been recreated by PTB in the 1990’s(?)).

AU-72

3365 Annex A Fig A.3 Ge Since the spark test apparatus is limited to 300V, how are these curves validated above 300V? Fig A.1 on resistive circuits also stops at 300V.

Limit the max voltage in Fig A.3 to 300V. Adjust graph accordingly.

Not accepted – adjusting the graph is a non-trivial task since access to the raw data used to generate the curves is unavailable. The validation of the curves was done as part of the research in the 1960’s that developed the various curves in 60079-11. Most of the other data was also obtained at the same time (Capacitance figures have been recreated by PTB in the 1990’s(?)).

AU-73

3395 Annex A Fig A.7 Te Fig A.7 indicates the battery as 20V max. But the text in line 3290 that refers to this

Correct this figure to indicate the battery as” Accepted

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(e.g. Table 1)

Type of comment


example indicates the maximum battery voltage is 22V.

“20 V nominal 22 V maximum”

DE-311

3425 -3439

A.5 Te Unfortunately the table ends with a series resistor of 40 Ohms. A statement at which value of the resistor the capacitance can be treated as negligible would be very helpful. There exist different approaches on that at the certification bodies


Not Accepted - no proposal provided and no data available.

DE-312

3454 B.1.2 Ed For consistency throughout the standard, the term apparatus is reserved already.

B.1.2 Spark Test Apparatus (STA) Accepted in part, “spark test apparatus”

DE-313

3454 B.1.2 Ge See comment for line 3454 Use STA instead of apparatus, where applicable. Not accepted this would require defining an abbreviation.

AU-74

3463 B.1.2 3 Ge The flow of the present text describes the tungsten wires with a diameter of 0,2 mm, and only much later, at B.1.7, it indicates the variation for the 10A spark test apparatus with 0,4 mm wire.

In B.1.2, after the para 2, provide an introduction: “The spark test apparatus described in B.1.2 refers to the 3 A test current limited apparatus, and B.1.7 describes the 10 A test current limited apparatus”

Accepted

DE-314

3468 -3472

B.1.2 4th para Ed Tolerances are missing for the dimensions required. The paragraph is partly written as requirement and partly as statement of fact. This should be adjusted to identify all the is required to ensure a consistent testing.

See Annex C in the attachment for proposal Accepted in principle Add some tolerance to the rotating speed. The electrode holder shall rotate at between 78 r/min and 82 r/min by an electric motor, with suitable reduction gearing if necessary.

DE-315

3473 -3476

B.1.2 5th para Ed This paragraph is written as a statement of fact (like a Note). If important it should be revised to be mandatory


Accepted Revised text: The axes of the shafts driving the cadmium disc and the electrode holder shall be 31 mm apart and electrically insulated from each other and from the baseplate of the spark test apparatus. The current shall be conducted through sliding contacts on the shafts which are geared

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(e.g. Table 1)

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together by non-conductive gears with a ratio of 50:12.

DE-316

3481 -3483

B.1.2 7th para Ed Again this paragraph does not clearly require what to do. There are some recommendations given, but no clear requirement that the number of contacts must be recorded.


Accepted Para changed to: Either a counting or a timing device shall be used to determine the number of revolutions of the shaft of the electrode holder.

AU-75

3494 B.1.3 2 Te The current text has a ‘shall’ that is not necessary or desired, as any of the optional sub clauses may correct the sensitivity without having to follow all the sub clauses. Current text: “When the sensitivity is not as specified, the following procedure shall be followed until the required sensitivity is achieved”

Change to: When the sensitivity is not as specified, the following procedure may be followed to achieve the required sensitivity:

Accepted in principle Delete the first para and revise 2nd para to: When the sensitivity is not as specified, one or more of the following may be conducted until the required sensitivity is achieved: And change title of B.1.3 to: Spark test apparatus sensitivity Add the following para to 9.1.3.1 and 9.1.3.2 referring to B.1.3: When sensitivity is not satisfactory, refer to B.1.3 for guidance.

AU-76

3501 B.1.3 e) 1 Te Writing the word “minimum” in the text is not necessary or desired, as the intention is to achieve the sensitivity: “e) connect the terminals to a 95 mH/24 V/100 mA circuit as specified in 9.1.3 and run the test apparatus with the contacts in air for a minimum of 20 000 revolutions of the electrode holder;”

Revise to: “e) connect the terminals to a 95 mH/24 V/100 mA circuit as specified in 9.1.3 and run the test apparatus with the contacts in air for 20 000 revolutions of the electrode holder;”

Accepted

AU-77

3518 B.1.4 Note 2 Ge The specification for grade 0 emery cloth grains is quite unnecessary

Remove Note 2 Accepted Also renumbered Note 1 to Note

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(e.g. Table 1)

Type of comment


DE-317

3547 B.1.6 1st para Ed This para is a statement of facts, but should have clear requirements.


Accepted in principle Revise 1st para to: Except as permitted by B.1.7, the use of the spark test apparatus shall be limited to the testing of intrinsically safe circuits with the following parameters:

DE-318

3553 -3562

B.1.6 Notes 1-4 Ed These Notes contain requirements. Revision of Notes or change to mandatory text. Accepted in part, made normative and reworded accordingly.

GB-245

3553 B.1.6 Note 1 ed This is permission and should not be a note. Make normative text, and modify: The apparatus canmay be successfully applied to circuits exceeding these limits but variations in sensitivity maymight occur.

Accepted

GB-246

3555 B.1.6 Notes 2 to 4 ed These notes are indispensable parts of this normative annex and should therefore be normative text.

Make normative text. Change “can” in line 3553 to “may”

Accepted

DE-319

3571 -3572

B.1.7 2nd para Ed This is a requirement. Revise text to read: The tungsten wires shall be replaced by wires with diameter increased from 0,2 mm to 0,4 ± 0,03 mm and the free length reduced to 10,5 mm.

Accepted

DE-320

3579 -3580

B.1.7 4th para Ed Exchange the ‘must’ by ‘shall’ The total inductance of the test apparatus and the inductance of the interconnection to the circuit under test shall be minimized. A maximum value of 1 µH shall be achieved.

Accepted

DE-321

3584 B.1.7 Figures B.1 – B.3

Ed Tolerances to be added where necessary. Should be discussed (see DE attachment Annex C)

Accepted in principle Dimensions and Tolerances revised

DE-322

3626 C Ge There are a lot of “should” in the Annex C. Revise to eliminate requirements. Not accepted. This is an informative annex, which makes recommendations. Should is not a requirement

DE-323

3636 Annex C C.1, 2nd para

ed The word “barrier” is not used in the calling clause 6.3 and may be mixed with “Safety Barrier) &.3 and other clauses use “partition” or “insulating partition”

Replace “barrier” with “insulating partition” Accepted (4 places)

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(e.g. Table 1)

Type of comment


Check also for other instances where “barrier is used for insulation partitions”

DE-324

3645 to 3648

C.1 3rd para te Following the approach stated in line 3649 to 3661, the wording should be adapted accordingly.

Where the distance between the conductive parts is partly clearance and partly separation distance through casting compound and/or solid insulation, the assessment of composite distances using equivalent clearance or separation distance through casting compound, calculated in the following manner can then be compared with the value in the relevant column of Table 5.

Not Accepted, original text is clearer.

DE-325

3654 to 3664

C.1 te Following the approach stated in line 3645 to 3661, a conversion Table is no longer needed.

Delete line 3662 and Table C.1 Accepted

AU-78

3654 C.1 Fig C.2 Ge This figure refers to A, B and C, and without the key, it requires going back and forth from the text to the figure to understand these alphabets.

Write the meaning of A, B, C in the key to this figure and delete lines 3649-3650.

Accepted

DE-326

3660 to 3661

C.1 te Level of protection ic is not considered. Change text to: If the result is 100% or more then the separation is infallible. If it is between 33.3% and 100% then failure of the separation is a countable fault for level of protection ia and ib. In the regard of level of protection ic, results less than 100 % are leading to not meeting the required separation. comment regarding failure and ic: as stated in 6.3.5 line 1382, those failures may be permitted for ic, if they do not impair intrinsic safety. To decide if intrinsic safety is impaired, shorts must be assumed as uncountable faults during safety analysis

Accepted in part, reworded: For Levels of Protection “ia” and “ib”, If the result is between 33,3 % and 100 % then failure of the separation is a countable fault. For Level of Protection “ic”, if the result is less than 100 % then the separation is not permitted to be used to maintain intrinsic safety. Line 1382 addressed by US-047.

AU-79

3664 C.1 Table C.1 Te This conversion table is not clear, and is technically incorrect where it writes that for U > 30V, the value from Table 5 is 3,0 mm for clearance in air. Because, from Table 5, at say 1000V (which is >30V) the requirement is 10,0mm. Unsure what this table is trying to say.

Rewrite the table correctly, or remove it altogether. Accepted in part, added 60V upper limit and example of use of the table.

DE-327

3664 C.1 table C.1 te If MT decides to keep Table C.1 – Conversion table, more than one table is needed (three like in

Clarify – otherwise take conversion tables of Ed. 6. Not accepted, Ed.6 tables, if corrected (as there are 4 errors) would all contain

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(e.g. Table 1)

Type of comment


Ed.6.). the same ratios so only one table is necessary.

DE-328

3666 C.2 1st para Ed Use “is” instead of “should” because Annex C is only informative

The voltage used is the voltage, determined in accordance with 6.3.3.

Accepted

DE-329

3693 C.2 Figure C.4 Te Where do these numbers come from? Why is it only for 60 V?

Clarify Accept in principle, deleted last sentence.

CH-47

3696 Annex D te Proposal requires verification in practice. Noted. This is derived from tests performed by a manufacturer.

GB-247

3696 Annex D ed Annex D uses the term “controlled semiconductor” whereas the rest of the standard uses “controllable semiconductor”.

Search and replace “controlled” with “controllable” throughout Annex D.

Accepted

US-102

3696 Annex D ge Annex D is written to assess the spark ignition safety for the intrinsically safe output circuits of either associated apparatus or intrinsically safe apparatus. However, 9.1.5.3 references the test method in Annex D for all active (controllable) semiconductor limiters. If Annex D is to be used for determining the let-through energy of these devices, the test method should be revised (made more generic) to include them.

Consider revising the test method of Annex D to include active (controllable) semiconductor limiters.

Accepted in part, introductory text change, no changes are necessary to the test method.

AU-80

3702 D.1 1 Ge It is not clear from the Introduction why the transient energy test is needed. The purpose is probably because the circuit shuts down the output after the transient, and hence cannot be spark tested. The second paragraph does refer to the transient test not being required for circuits that remain active during spark testing.

Add further description in the first sentence: “When the output voltage and current are limited by semiconductor limitation circuits that shut down when excess voltage and/or current is detected, this annex provides guidance for the measurement of the maximum transient let-through energy during the response time of controlled semiconductor current or voltage limitation circuits that cause the output to exceed allowable steady state limits”

Not Accepted. This is a test specification, the calling text (new 5.3) defines when the test is needed. This is not limited to shutdown circuits. See also DE-330.

DE-330

3707 to 3708

D.1 2nd para te The text creates the impression, that testing an electronically current limited circuit with the STA acc. to 9.1 with “active limitation” is sufficient and the transient energy test can be skipped. That is not true. “Smart sources” may not be sufficiently tested with the STA acc. to 9.1.

Delete sentence here. It should be moved to 9.1.5.3 and revised to become clear

Accepted in part, sentence deleted. Both Annex D and STA are required since STA cannot test supply faults and Annex D Plim is not necessarily spark safe.

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(e.g. Table 1)

Type of comment


Especially the characteristic of the “restart” after a short influences ignitability. After a short, the source may not transfer power into the circuit anymore (fold back characteristic). This may lead to no ignition with the STA, but not to Intrinsic Safety. To test electronically current limited circuits with the STA, special preparations may be necessary, which are not part of clause 9.1.

AU-81

3707 D.1 2 Ge Revise the text of the second para for clarity. Current text: “These tests are not required for current limiting circuits if the controlled limitation is active during spark testing of the circuit output.”

Revise to: “These tests are not required for current limiting circuits if the controlled limitation remains active during spark testing of the circuit output.”


DE-331

3710 D.2 1st para te/ed “Energy let-through” and “Let through energy” are “transient energies” acc. to definition in 3.18.2. It is not helpful/necessary to find different expressions for the same issue.

Change in Annex D all similar issues “let through energy” in “transient energy” described in 3.18.2

Accepted in part. “excess transient energy” used since the energy being measured is not just the energy above the steady state.

US-103

3710 D.2 ed The initial application of Um and Ui is what causes the transient, and should be specified as such.

…as well as the initial application of Um, Ui …. Accepted in part, “initial” added, also added startup test in D.5.1 but for “ia” and “ib” only.

DE-332

3711 D.2 1st para te Ui on this place is unclear (Ui or UIN ?) Furthermore faults the apparatus may cause release of transient energy (e.g. opening the feedback circuit in a DC/DC converter)

Change Ui in UIN

modify: … Um, Ui and short-circuit of a load or faults of the circuitry e.g. opening the feedback circuit in a DC/DC converter.

Accepted in principle, paragraph reworded for clarity with DC/DC example included.

US-104

3712 D.2 ed The sentence ‘In general…’ is contradictory with the previous sentence, and with the subsequent tests.

Remove the sentence beginning with ‘In general…’

Accepted in part. This sentence separates out the up-stream faults (which apply a voltage increase) and the down-stream faults (which apply a current increase), the subsequent tests maintains this separation. Sentence re-worded to make this clearer.

DE-333

3713 D.2 1st para ed Missing a diagram: Where is static/operational area and where is the transient area?

Clarify with a diagram or plot static/ operational area and transient area (e.g. Figure E.2 in the 6.Ed. of IEC 60079-11)

Accepted in principle, new diagram added. Ed.6 Figure E.2 is not representative when the

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(e.g. Table 1)

Type of comment


voltage is not constant.

DE-334

3716 D.2 Table D.1 Te/ed This table can lead to confusion. What is meant with “before” and “after” the voltage limiter? Where exactly is the shunt limiter placed?

Change “before” and “after” in: “upstream” and “downstream” or Clarify with a schematic for the shunt limiter configuration. (see also comments in DE/UG on line 3731 Figure D.1)

Accepted in part: “upstream” and “downstream” terminology used.

GB-248

3716 Table D.1 ed Inconsistent use of “Zener”

Replace “Zener clamp” with “Zener diode shunt assembly”

Accepted

DE-335

3717 D.2 Table D.1 te A common application of semiconductor current or voltage limitation circuits are intrinsically safe batteries for portable equipment. Often the input voltage to the circuit Uin as well as the output Voltage Uo is only limited by the maximum open circuit voltage of the cells. The supply fault test would not be applicable in that case

Add note below table D.1 Note: Supply fault tests are not applicable if the circuit input is directly connected primary or secondary cells and Uo of the circuit equals to the maximum open circuit voltage of the cells

Accepted in principle, line 2 of Table D.1 changed to include cells and batteries.

GB-249

3717 D.2 te Clarify that the most onerous circuit configuration for the test is required.

Add paragraph. These test should be carried out on circuits arranged in the most onerous way for the test, i.e. the worst case combination of voltage, current and response time. This requires detailed knowledge of the circuit and its operation, and includes consideration of manufacturing tolerances, temperature variations, fault considerations, variation in timing of semiconductors. Worst case operation could be immediately following switch-on, or after a warmup period.

Accepted in part, some aspects are not practical, e.g. obtaining a comparator with a response time equal to the data sheet specified maximum. Text modified and given separate subclause D.3.

DE-336

3726 D.3 3st para te/ed “triggering from the channel product function” is not possible with most common DSO.

Triggering synchronous to the application of the fault condition is sufficient.

Accepted, triggering changed to voltage or current.

GB-250

3728 D.3 3rd para ed Typo, “test” should be “set” Replace “test” with “set”. Accepted

DE-337

3729 D.3 3st para te/ed It is only possible to trigger the oscilloscope based on the fault pulse UFAULT with the “fault-pulse-event”

Change the word “pre-trigger” into “post-trigger” Not Accepted. All but the oldest digital storage ‘scopes are able to display pre-trigger information.

DE-338

3731 D.3 Figure D.1 te It is advisable to apply all tests from Table D.1 to the circuit under test. The internal functionality of the Device Under Test (DUT) cannot always be easily assessed by the test laboratory.

Replace the dotted rectangular with the internal circuits simply with a rectangular black box. In this case Table D.1 can also be simplified (or

Not Accepted, this is not designed to be a black box test. Knowledge of the internal functionality is

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(e.g. Table 1)

Type of comment


can be cancelled).

required to know which tests you are performing, ensuring that any redundant circuits are disabled, and that any steps to set the circuit up in a “most onerous” case have been taken

DE-339

3731 D.3 Figure D.1 te/ed Uo and Io shall be marked in the schematic Mark Uo and Io in Figure D.1 Not Accepted. There is no Uo or Ui for internal circuits. They are voltages that do not necessarily represent the worst case transient. They are also applied differently depending on the test being operated. For example a load fault test would normally have Uo connected at the UIN point, but a supply fault test would have Uo connected at the UFAULT point.

DE-340

3736 Annex D.3 Figure D.1, Key

te Is not a must have – add text Semiconductor controlled current limiter for safety purposes (if any – or may have redundancy)

Accepted in part, all items inside the dotted line may or may not be present as stated by the note. “(if-any)” has been removed from key item 2 to avoind confusion.

DE-341

3738 D.3 Figure D.1 te Key 5: the diode in schematic is connected in the wrong polarity

Turn around diode 5, (see also comments in DE/UG in line 3731 Figure D.1)

Accepted in part, diagram altered to show a thyristor. See also DE-339.

DE-342

3749 D.3 Figure D.1 ed Title of Figure D.1 is not correct New title “Example for a circuit configuration” Accepted in part, calling text expanded. The circuit configuration has optional parts to it as stated in the note, but is meant to represent all circuits which can be tested using this test. If there are applicable circuit configurations that do not meet this we should consider altering the circuit

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(e.g. Table 1)

Type of comment


diagram.

DE-343

3753 D.3 para after Figure D.1

te What does it mean “… switch to provide suitable speed …”. Here it is helpful to quantify the range of permissible switching speed

Change to “… switch to ensure a switch on time of less than 1 µs …”.

Accepted in part. 1µS may not be sufficient in all cases, changed to 5%.

DE-344

3753 D.3 para after Figure D.1

te What does it mean “… and low on resistance”. Here it is helpful to quantify the maximum permitted resistance.

Change to “… and not more than 100 mOhms”. Accepted in part. 100mOhms may be too large in some cases. Changed to “less than 5% of the applied voltage”.

DE-345

3761 D.3 ed/te When testing controlled semiconductor current limiters they should be adjusted to the maximum current limit threshold considering circuit tolerances.

…. at the top end of their manufacturing voltage or current limit threshold …

Accepted in part, see GB-249.

DE-346

3765 D.4 1st para Ed Reference to Table is incomplete …defined in Table D.2, … Accepted

US-105

3765 D.4 Par 1 ed Appears to be an extra period at the end of “Table D.,”

Change from “Table D.,” to “Table D,” Not Accepted, see DE-346.

AU-82

3765 D.4 1 Ed Text is missing the table number for D.2 Requires rewording as power does not produce a spark. There is also a typo “steady sate”

Modify the text: PLIM is determined depending on the configuration as defined in Table D.2, and represents the maximum steady state power output that does not cause a spark ignition.

Accepted in part. Text altered as the limit will include the safety factor, so will usually be lower than the limit of spark ignition.

US-106

3765 D.4 Par 1 ed Typo “sate” should be “state” Change “sate” to “state” Accepted

AU-83

3768 D.4 Table D.2 te In the table Po is referred to as the thermal ignition limit. This is not in line with the current definition of Po

Modify the text: This may be greater than the thermal ignition limit PO. PLIM may be larger than the maximum output power Po

Accepted in part. Changed to ”This may be greater than Po for the apparatus.”

GB-251

3768 Table D.2 ed Uo is not necessarily a fault condition. Inconsistent use of “Zener”

Replace with: UO is the maximum steady state voltage under fault conditions of specified in 5.2 as defined by a crowbar, Zener clampdiode shunt assembly, voltage regulator (if suitably redundant) or equivalent and taking into account manufacturing tolerances and variations due to temperature.

Accepted

AU-84

3769 D.4 Table D.2 ed Reference for Resistively limited item is not clear Modify the text: Resistively limited (at 7) in accordance with D.3

Accepted in part, reference to D.3 not considered

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(e.g. Table 1)

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and key 7 of figure D.1 necessary, but reference to Figure D.1 added.

AU-85

3769 D.4 Table D.2 ge Modify the remark for the Resistively limited table item to prevent misunderstanding of the divide by 4

Modify the text: Where Table A.1 has been used for a resistive limited circuit, the power considered safe needs to be reduced to consider the maximum power transfer theorem.

Not Accepted, explaination of the derivation of the divide by 4 is not necessary, and should be obvious anyway.

AU-86

3769 D.4 Table D.2 te Uo is already a defined term in the standard. Modify the text: Uo is the maximum output voltage.

Accepted in part, Uo re-named UOUT where applicable.

AU-87

3769 D.4 Table D.2 te “little inductance or capacitance”, is not well defined and will lead to inconsistent application of the clause. In the current text, the following conditions are not accounted for: More than a little capacitance and no inductance More than a little inductance and no capacitance Re-word to cover all conditions

Modify the text: ILIM: Where the total inductance and capacitance is less than 1% of the allowed values in the relevant ignition curves and tables given in Annex A, ILIM may be taken as a quarter of the current allowed by Table A.1. Where the total inductance or capacitance is greater than 1% of the allowed values in the relevant ignition curves and tables given in Annex A, ILIM may be taken from the limit diagrams for rectangular supplies provided in IEC 60079-25. ILIM may be larger than the current at which the limiter activates, but should not be lower.

Accepted

AU-88

3769 D.4 D.2 Ge The terms PlM, EA, EOUT, and ELT and their relationships should be shown on a figure of power vs time

Add new figure Accepted

DE-347

3770 D.4 te The starting point in Annex E of the 6th edition was defined by exceeding IO. Why is the starting point now at PLIM?

Consider exceeding UO or IO as starting point. Not Accepted, the starting point in Ed. 6 assumed a constant output voltage which is not practical. The test is to measure the excessive transient energy: energy is the integration of power over the time for which it is excessive, not the voltage or current.

DE-348

3772 D.4 ed Is “t . PLIM” the formula for the integral of power over time?

Consider to correct formula Not Accepted, PLIM is a constant so does not change with time.

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(e.g. Table 1)

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AU-89

3779 D.5.1 1 Ge Reword the first 2 paragraphs to ensure that more faults than 5.2 permits for the level of protection should not be applied.

Modify the text: The testing of controlled semiconductor voltage limitation circuits should occur after the application of faults in 5.2 which produce the most onerous condition. Where redundancy is used to comply with the countable fault requirements, disabling the redundant circuits to leave only one of the similar functional blocks active might produce the most onerous condition.

Accepted in part. Due to the complexity of these circuits and their possible interaction, It is considered that a single functional block should pass this test irrespective of the number of redundant blocks or their relation to 5.2. Added paragraph “Other than deactivation of redundant circuits…” to D.3.

DE-349

3790 D.5.1 ed It is not clear how to determine the “maximum supply voltage“. This voltage depends on the specified application in the field.

Change to: “… maximum supply voltage under fault condition in the application“.

Not Accepted, The exact application might not be known. The circuit itself is known and may have internal limitations on this, or as the example gives, it might be the input rating Um or Ui

GB-252

3790 D.5.1 5th para ed “also considering” is confusing as it implies there are two sets of conditions.

Replace “, also considering the fault conditions of 5.2” with “under the conditions specified in 5.2”

Accepted

DE-350

3792 + 3815

D.5.1 + D.6.1

te The requirement of a Zener diode as load does not fit to the sentence in line 3801, were a Zener diode might not be the most onerous load.

Consider a few required load scenarios together with the statements in D.5.2 and D.6.2

Accepted in part, a better description of the worst case load has been added.

GB-253

3793 D.5.1 6th para ed Inconsistent use of “Zener” Add “diode” after Zener Accepted

DE-351

3797 + 3818

D.5.2 + D.6.2

te The requirements for loads connected to the circuit are too unspecific. This lead to different results depending on the agency or to an endless amount of tests.

Consider a few required load scenarios together with the statements in D.5.1 and D.6.1

Accepted in part, see DE-350. The most onerous load will depend on the circuit so this cannot be prescriptive.

GB-254

3802 D.5.2 End of 1st para

ed Inconsistent use of “Zener” Add “diode” after Zener Accepted

AU-90

3807 D.6.1 1 ed It is unclear how this paragraph is to be applied. Delete “so they may remain in circuit and active” Accepted in part, paragraph reworded.

AU-91

3809 D.6.1 2 Reword the second paragraph to ensure that more faults than 5.2 permits for the level of protection should not be applied.

Modify the text: The testing of controlled semiconductor current limitation circuits should occur after the application

Accepted in part, see AU-089.

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(e.g. Table 1)

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of faults in 5.2 which produce the most onerous condition. Where redundancy is used to comply with the countable fault requirements, disabling the redundant circuits to leave only one of the similar functional blocks active might produce the most onerous condition.

US-107

3899 E.3.2 a) te I believe that we mean these are the maximum input parameters: shall have minimum input parameters of Ii:380 mA and Pi: 5,32 W;

Change minimum to maximum Not accepted. Correct as stated.

IT-27 3943 E.4.1 All examples

te In the examples of marking of the FISCO devices, the EPL is not indicated. This is in contrast with the example of marking in clause 11.4

Change as necessary.

Accepted

IT-28 3991 Annex E Figure G.1 ed Modify as proposed Figure E.1 – Typical FISCO system Key 1 FISCO Terminator 2 FISCO Power supply 3 Data 4 FISCO Hand Held Terminal (HHT) 5 FISCO Field device 6 Trunk 7 Spur Number 4 should be close to the arrow not inside the box

Accepted

FR-35

3991 E.4.1 Figure G1 ed Wrong figure reference Figure E.1 (instead of G.1) Accepted

US-108

4104 Table F.1 Step 13 ed I believe that we are saying that you need to have a “pass” on all three formulas, however this is not super clear to me. This would be better clarified with numbering and a clear statement.

Restate: “DUT has passed if condition of 1, 2,and 3 are met.” Then number the formulas:

1) (log Px) ≤ (log Pa), or Px ≤ Pa; 2) …; 3) ...

Accepted in part, “all three of” used.

GB-255

4123 New te In a previous set of comments it was agreed that the information presented in 31G/100/DC for non-linear supplies would be added to 60079-11. This was assigned to the Transients task group within the maintenance team, but is actually a broader

Reconsider the application of 31G/100/DC introduce this in to the next draft.

Noted. 31G/100/DC was reconsidered, but not accepted for the reasons given in MT11_DOC_118. SC31G requested to reverse their previous

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(e.g. Table 1)

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subject than that. decision to include this as an annex

US-109

4135 Bibliography ed Should UL1642, Standard for Lithium Batteries be listed last?

Swap lines 4135 and 4136. Accepted

Annex of AU.doc

AU rewrite of 9.1 9.1 Spark ignition assessment and testing

9.1.1 General

All circuits requiring spark ignition consideration shall be assessed or tested to show that they are incapable of causing ignition under the conditions specified in 5.2 for the appropriate Group and Level of Protection of the equipment.

Normal and fault conditions shall be assessed or simulated with safety factors as described in 5.2 taken into account, and with the maximum values of the external capacitance (Co) and inductance (Lo) or inductance to resistance ratio (Lo/Ro) for which the equipment is designed.

The spark energy shall be considered at each point where an interruption, short circuit, or earth fault may occur. A circuit may be exempted from a type test with the spark-test apparatus if its structure and its electrical parameters are sufficiently well defined for its safety to be deduced from the reference curves Figures A.1 to A.6 or Tables A.1 and A.2, or by the methods described in Annex A.

For Level of Protection “ia” and “ib”, the consideration of the energy or the use of the spark test apparatus to produce short circuits, interruptions and earth faults shall be a test of normal operation and is a non-countable fault

- at external connection facilities, - at internal connections or across internal creepage distances, clearances, distances

through casting compound and distances through solid insulation not conforming to 6.1.2.2. or 6.1.2.3.

Consideration of the energy or the use of the spark test apparatus shall not be required for the following situations

- across infallible separations, or in series with infallible connections, - across creepage distances, clearances, distances through casting compound and distances through solid insulation conforming to Table 5, Table 6 or Table 7, - within encapsulation used for the protection against spark ignition meeting the requirements of 6.5.2.1, - within associated intrinsically safe equipment other than at its intrinsically safe circuit terminals, - between terminals of separate circuits conforming to 6.2.1, apart from the exceptions described in 6.4).

For Level of Protection “ic”, the consideration of the energy or the use of the spark test apparatus shall be considered for the following situations:

- at external connection facilities, - across separations less than the values specified in Table 5, Table 6 or Table 7; - in place of normally sparking contacts such as plugs/sockets, switches, pushbuttons, potentiometers; - in place of components that are not suitably rated under normal operating conditions

Circuits using series or shunt active semiconductor circuits for spark limitation may alternatively be tested for their let-through energy in accordance with 9.1.5.3.

The energy released or the result from the spark test apparatus applied at the chosen test points shall be less than the allowable energy or result in no ignition in the spark test apparatus for the test series.

NOTE A circuit assessed using the reference curves and tables may cause ignition when tested using the spark test apparatus. The sensitivity of the spark test apparatus varies, and the curves and tables are derived from a large number of such tests.

9.1.2 Spark test apparatus and its use

The spark test apparatus shall be that described in Annex B except where Annex B indicates that it may not be suitable. In these circumstances, an alternative test apparatus of equivalent sensitivity shall be used and justification for its use shall be included in the definitive test and assessment documentation.

Where voltages and currents are specified for the test without specific tolerances, a tolerance of ±1 % is to be used.

The sensitivity of the spark test apparatus shall be checked before each test series is carried out in accordance with 9.1.3. For this purpose, the test apparatus shall be operated in a 24 V d.c. circuit containing a 95 (± 5) mH air-cored coil. The current in this circuit shall be set at the value given in Table 15 or Table 16, using the ‘ignition’ column, according to the appropriate group and the safety factor of the test mixture. The sensitivity shall be considered to be satisfactory if an ignition of the explosive test mixture occurs within 440 revolutions of the wire holder with the wire holder at positive polarity.

Each circuit shall be tested for the following number of revolutions, with a tolerance of +10 0 % of the wire holder in the spark test apparatus, with no ignition allowed to take place: a) for d.c. circuits, 400 revolutions (5 min), 200 revolutions at each polarity; b) for a.c. circuits, 1 000 revolutions (12,5 min); c) for capacitive circuits, 400 revolutions (5 min), 200 revolutions at each polarity. Care shall be taken to ensure that the capacitor has sufficient time to recharge (at least three time constants) between each discharge. The normal time duration between when the tungsten wire leaves the cadmium disc and then next wire contacts the disc (for the 4 tungsten wire arrangement) is about 68 ms. Where this is inadequate for the recharge of the capacitor, the duration shall be increased by removing one or more of the wires or by slowing the speed of rotation of the spark test apparatus. When wires are removed, the number of revolutions shall be increased to maintain the same number of sparks.

After each test in accordance with a), b) or c), calibration of the spark test apparatus shall be repeated. If the calibration does not conform to 9.1.3, the ignition test on the circuit under investigation shall be considered invalid and shall be repeated.

When there is a doubt that the apparatus is over-sensitive (for example, if a test has resulted in an ignition which was unexpected), the sensitivity may be checked by applying the ‘no-ignition’ column of Table 15 or 16, as applicable. If an ignition occurs within 400 revolutions, then investigation of the source of the over sensitivity shall take place and the ignition test on the circuit under investigation shall be considered invalid and shall be repeated.

NOTE Bent, frayed, or cadmium coated tungsten wires of the spark test apparatus can change its sensitivity. This might cause invalid test results

9.1.3 Test gas mixtures and spark test apparatus calibration current

9.1.3.1 Explosive test mixtures suitable for tests with a safety factor of 1,0 and calibration current of the spark test apparatus

The explosive test mixtures as given in Table 15 shall be used, according to the stated Equipment Group which is being tested. The explosive mixtures specified in this clause do not contain a safety factor. If a safety factor of 1,5 is required, the electrical values of the circuit shall be increased according to 9.1.4.

Table 15 – Compositions of explosive test mixtures adequate for 1,0 safety factor

Group Compositions of explosive test mixtures Vol. % in air

Current in the calibration circuit for ignition mA

Current in the calibration circuit for no ignition mA

I (8,3 ± 0,3) % methane 110 to 111 87 to 88 IIA (5,25 ± 0,25) % propane 100 to 101 79 to 80 IIB (7,8 ± 0,5) % ethylene 65 to 66 51 to 52 IIC (21 ± 2) % hydrogen 30 to 30,5 23 to 24 In special cases, equipment which is to be tested and marked for use in a particular gas or vapour shall be tested in the most easily ignited concentration of that gas or vapour in air.

NOTE The purity of commercially available gases and vapours is normally adequate for these tests, but those of purity less than 95 % should not be used. The effect of normal variations in laboratory temperature and air pressure and of the humidity of the air in the explosive test mixture is also likely to be small. Any significant effects of these variations will become apparent during the routine calibration of the spark test apparatus.

9.1.3.2 Explosive test mixtures suitable for tests with a safety factor of 1,5 and calibration current of the spark test apparatus

The preferred test mixtures are those specified in 9.1.3.1 with a safety factor applied by an increase of voltage or current as applicable. Where this is not practical and a more severe test mixture is used to achieve a factor of safety, a safety factor of 1,5 is considered as having been applied for the purpose of this standard when the composition shall be as given in Table 16. Table 16 – Compositions of explosive test mixtures adequate for 1,5 safety factor

Group Compositions of explosive test mixtures Volume % Current in

the calibration circuit for ignition mA

Current in the calibration circuit for no ignition mA

Oxygen-hydrogen-air mixture Oxygen-hydrogen mixture

Hydrogen Air Oxygen Hydrogen Oxygen

I 52 ± 0,5 48 ± 0,5 85 ± 0,5 15 ± 0,5 73 to 74 57 to 58

IIA 48 ± 0,5 52 ± 0,5 81 ± 0,5 19 ± 0,5 66 to 67 51 to 52

IIB 38 ± 0,5 62 ± 0,5 75 ± 0,5 25 ± 0,5 43 to 44 33 to 34

IIC 30 ± 0,5 53 ± 0,5 17 ± 0,5 60 ± 0,5 40 ± 0,5 20 to 21 16 to 17

9.1.4 Circuit testing

9.1.4.1 General

The circuit to be tested shall be based on the most incendive circuit that can arise, toleranced in accordance with Clause 7. In all cases, when considering the energy at the test points, increase the mains (electrical supply system) voltage to 110 % of the nominal value to allow for mains variations, or set other voltages, for example batteries, power supplies and voltage limiting devices at the maximum value in accordance with Clause 7.

When an infallible current-limiting resistor is used with a capacitor, it is an acceptable alternative to consider the capacitor as a battery and the circuit as resistive.

Where a safety factor of 1,5 is required it shall be obtained by one of the following methods:

a) Use the test mixture specified in Table 15 for a safety factor of 1,0, and 1) for inductive and resistive circuits, increase the current to 1,5 times the fault current by decreasing the values of limiting resistance, and if the 1,5 factor cannot be obtained, further increase the voltage 2) for capacitive circuits, increase the voltage to obtain 1,5 times the fault voltage.

When using the curves in Figures A.1 to A.6 or Tables A.1 and A.2 for assessment, this same method shall be used.

b) use the more easily ignited explosive test mixtures in accordance with Table 16 for a safety factor of 1,5.

NOTE The purpose of the application of a safety factor is to ensure either that a type test or assessment is carried out with a circuit which is demonstrably more likely to cause ignition than the original, or that the original circuit is tested in a more readily ignited gas mixture. In general, it is not possible to obtain exact equivalence between different methods of achieving a specified factor of safety, but these methods provide acceptable alternatives.

For simple circuits of the types for which the curves in Figures A.1 to A.6 apply, the spark test apparatus applying a short-circuit is the most onerous. For more complex circuits, the conditions vary and a short-circuit test may not be the most onerous, for example, for constant voltage current-limited power supplies, the most onerous condition usually occurs when a resistor is placed in series with the output of the power supply and limits the current to the maximum which can flow without any reduction in voltage.

Non-linear power supplies require special consideration. See Annex F for information on an alternative method for the ignition testing of semiconductor limiting power supply circuits.

9.1.4.2 Circuits with both inductance and capacitance

(as before, with no changes proposed, except for further editorials mentioned in AU comments)

A circuit containing energy stored in both capacitance and inductance, may be difficult to assess using the curves in Figures A.1 to A.6. For example, capacitive stored energy may reinforce the power source feeding an inductor. Where the total capacitance, or inductance, assessed against the requirements of 5.2 is less than 1 % of the value allowable by using the ignition curves or tables given in Annex A, then the maximum allowable capacitance, or inductance, respectively, may be taken as that allowed by the curves or tables.

The circuit shall be assessed for compliance using either of the following methods: a) tested with the combination of capacitance and inductance, or b) where linear (resistive current limiting) circuits are being considered

1) the allowed inductance and capacitance determined by using the relevant ignition curves and tables given in Annex A when; a. all inductance and capacitance is distributed for example, as in a cable or, b. the total inductance of the circuit (excluding the cable) is < 1 % of the allowed value of inductance determined by using the relevant ignition curves and tables

given in Annex A or, c. the total capacitance of the circuit (excluding the cable) is < 1 % of the allowed value of capacitance determined using the relevant ignition curves and tables

given in Annex A 2) the allowed inductance and capacitance is determined by using the relevant ignition curves and table given in Annex A reduced to 50 % when:

a. the total inductance of the circuit (excluding the cable) ≥ 1 % of the allowed value of inductance determined by using the relevant ignition curves and tables given in Annex A and

b. the total capacitance of the circuit (excluding the cable) ≥ 1 % of the allowed value of capacitance determined by using the relevant ignition curves and tables given in Annex A.

The reduced capacitance of the circuit (including cable) shall not be greater than 1 µF for Groups I, IIA, and IIB and 600 nF for Group IIC.

The values of allowed inductance and capacitance determined by these methods shall not be exceeded by the sum of all the lumped and distributed inductances and the sum of all lumped and distributed capacitances in the circuit, respectively.

Where the application of the above leads to reduced values of Lo and Co for use with lumped inductance and capacitance, this shall be included in the manufacturer’s instructions.

9.1.4.3 Circuits using controllable semiconductor limitation

After the output voltage (for voltage limitation) or current (for current limitation) has stabilized, the circuit shall be incapable of causing ignition for the appropriate Level of Protection of the equipment in the conditions of 5.2. Additionally, where intrinsic safety relies on operation of controllable semiconductor limitation circuit, the transient energy (that is the energy in excess of the allowable steady state maximum) of the circuit during operation shall not exceed the following value for the appropriate group: – Group IIC equipment 20 µJ – Group IIB and Group III equipment 80 µJ – Group IIA equipment 160 µJ – Group I equipment 260 µJ

Where ignition tests with the spark test apparatus are not appropriate for testing the transient energy caused by faults in the supply (for example, for voltage limiting crowbar circuits), this transient energy shall be assessed, for example from oscilloscope measurements.

NOTE Guidance for performing this test is available in Annex D.

Annex of DE.doc

DE proposal for new Figure 1 in 6.2.1

Key

1 Cover / enclosure: non-conductive, or conductive and earthed 2 Partition in accordance with 6.2.1 b); in this example, it shall be homogeneous with the base or cemented to it. T Distances in accordance with 6.3 d1 ≥ 3 mm, when cover / enclosure is conductive and earthed d2 ≥ 6 mm d3 ≥ 50 mm or d4 ≤ 1.5 mm

NOTE The dimensions are the clearance distance around the insulation, as indicated above, not the thickness of the insulation.

Figure 1 – Separations at connection facilities

DE proposal for revised text of 6.2.5 considering the DE comments on 6.2.5 6.2.5 Connections and accessories for intrinsically safe apparatus when located in the non-hazardous area Intrinsically safe apparatus may be provided with connection facilities that are restricted to use in a non-hazardous area e.g. data downloading and battery charging connections. Such facilities shall be provided with protection to ensure the ratings of the safety components within the intrinsically safe equipment comply with 7.1. The connections shall be provided with means to prevent short-circuiting or to prevent delivery of ignition-capable energy to the contacts of the intrinsically safe apparatus when any pair of the contacts is accidentally short-circuited while in the hazardous area. This shall be accomplished by:

a) limiting the output in accordance with this standard, or; b) for Group II intrinsically safe apparatus, a degree of protection by enclosure of at least IP30 shall be provided for the connection facilities and shall be marked with a warning

label as specified in item c) or d) of 11.3. The separation distances between the charging contacts shall comply with 6.3 considering the open-circuit voltage of the internal circuitry, for example that of the battery.

Where the intrinsically safe apparatus connection facilities are not restricted to the use of an accessory listed in the certificate, the maximum voltage Um, which can be applied to these connections, shall be stated in the certificate and marked on the apparatus.” The Um at the connection facilities shall be assumed to be the normal mains supply voltage e.g. 250 V a.c., unless specified otherwise. Protection circuitry and components may reside in either the intrinsically safe apparatus or the non-hazardous area accessory. If any part of the protection circuit is located in the non hazardous area accessory, the accessory shall be listed in the certificate. Countable fault analysis of 5.2, thermal or spark ignition considerations are not required for the non-hazardous area accessory, although protection components shall comply with the applicable requirements in chapter 7.1 after the application of non-countable faults. EXAMPLE: A fuse and suitably rated single Zener diode fulfil the requirement for voltage limitation. Alternatively IEC 60079-14 provides requirements for derivation of Um below 250

V a.c.. NOTE 1: The reduced countable fault requirement is due to the likelihood that a failure of the non-hazardous area accessory would be detected. These requirements do not apply to non-hazardous area equipment used for manufacturing or for test, repair or overhaul by the manufacturer or a suitably assessed service facility.

DE Proposal for a new Flowchart for clause 6.3

Annex A to DE-comment on line 2947 - 2950 Clause 9.11.1.3 of 931G/269/CD - ExTAG/205/CD INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC) SYSTEM FOR CERTIFICATION TO STANDARDS RELATING TO EQUIPMENT FOR USE IN EXPLOSIVE ATMOSPHERES (IECEx SYSTEM)

Title: ExTAG Draft Decision Sheet Application of clause 10.10 transformer tests of IEC 60079-11:2006 Circulation: ExTAG Members

INTRODUCTION

This draft ExTAG Decision Sheet was drafted by PTB considering the discussions with manufacturers and other ExTLs. This document is issued for consideration during the 2010 Berlin ExTAG and ExMC Meetings

Address:

SAI Global Building Level 7 286 Sussex Street Sydney NSW 2000 Australia

IECEx Secretariat Contact Details: Tel: +61 2 8206 6940 Fax: +61 2 8206 6272 e-mail: [email protected] http://www.iecex.com

ExTAG Secretary Mr Michel Brenon/LCIE Tel: +33 1 40 95 5519 Fax: +33 1 40 95 5520 e-mail: [email protected]

http://www.iecex.com/

mailto:[email protected]

IECEx / ExTAG DECISION SHEET

Title: Application of clause 10.10 transformer tests of IEC 60079-11:2006

Standard(s) IEC 60079-11:2006

Clause(s): 10.10

Subject: maximum permissible temperature during worst case transformer test Status of Document: Draft

Keywords transformer test, permissible temperature, thermal class

Date: 2010-07-27 Originator of proposal: PTB

Related document: N/A

Question: What is meant by “permissible value” for Insulation materials in a type 1 or 2 transformer for galvanic isolation between IS and non-IS circuits? Background: IEC 60079-11 defines that a transformer for galvanic separation that meets the requirements of clause 8.1 or 8.2 is an infallible transformer. According to the type test (clause 10.10) a worst case scenario (supplying with 1.7 x fuse current of primary protecting device at maximum voltage Um with a secondary load that results in maximum transformer load) is required to be applied to the transformer. After stressing the transformer this way a dielectric strength test shall demonstrate that the galvanic separation is still achieved. The second to last paragraph of clause 10.10 reads "the permissible value for the class of insulation given in IEC 60085 shall not be exceeded for type 1 and type 2 transformers”.

Note: IEC 60085 uses the term “thermal class” NOT “class of insulation” According to clause 8.1 and 8.2 the transformer type test is not done at normal continuous operating conditions, but with a worst case failure scenario to get the maximum power dissipation in the transformer to test if the galvanic isolation is still achieved.

Usually transformers are designed in a way that the thermal class of their electrical insulating system (EIS) is not exceeded during continuous operating conditions at the maximum ambient temperature.

For other than normal operating conditions IEC 60085 refers to product TCs to determine the operating conditions under which the maximum temperature of the device may differ from the thermal class of the EIS (Clause 4.1 of IEC 60085). To prevent destroying the EIS applying protective devices like fuses, thermal non-resetting devices etc. is a common means often used by manufacturers of transformers and described in several transformer product standards (e.g. IEC 61558-1 for safety transformers).

Answer:

As suggested by IEC 60085 it makes sense to look into a product standard for safety transformers to get more details about permissible values for special operating conditions (failure mode) as requested by the type test in IEC 60079-11 clause 10.10. Due to safety reasons looking into the transformer standard for protection against electric shock (IEC 61558-1) is a good choice to get permissible values for the EIS.

The recommendation is therefore to take the values from IEC 61558-1 as permissible values for the thermal class of the EIS. For the nominal operation the values of Table 1 in IEC 61158-1 should be taken and for the type test of an infallible transformer according IEC 60079-11 clause 10.10 the values of Table 3 in IEC 61158-1.

Thermal Class of the insulation

material

Limit temperature acc. to IEC 60085

°C

Limit temperature acc. to IEC 61158-1,

Table 1, °C

Test limit temperature acc. to IEC 61158-1, Table

3, °C

A 105 100 150

E 120 115 165

B 130 120 175

F 155 140 190

H 180 165 210

Remark: Column 3 values are slightly lower than column 2 values to consider hot spots when the method of winding resistance increase is used.

Annex B to DE-comments on line 3345 – 3352 Annex A, A.4 of 931G/269/CD - WG4 Report

SC 31G – WG4 Report

2016-10-06

INTERNATIONAL ELECTROTECHNICAL COMMISSION

SUBCOMMITTEE 31G: INTRINSICALLY SAFE APPARATUS

REPORT OF THE ACTIVITIES OF IEC SC 31G - WG4: Spark Test Apparatus

The last meeting of SC 31G – WG4 took place in Frankfurt (Main), Germany on the 6th of October 2016 PTB presented current scientific results regarding the Electronic Spark Tester (EST). The results, presented by Carsten Uber and Rajiv Shekar, gave a very good insight in the chemo-physical reaction during the creation of a make spark in the STA. A request from CRC mining (Australia) for support for the start of a NW on a Technical Specification for an EST for Group I has been discussed and rejected because the WG thought, that the research results are not sufficient to start a new work on this subject. The WG recommended to CRC mining to wait with the start of this project until reliable results from the PTB research are available. PTB estimated to have reliable results not before 2019. A discussion about discovered discrepancies between certified IS parameters and recently done practical tests with the STA prompted the WG to give the following recommendation to MT 60079-11:

- Consider the dynamic behaviour of electronic limited IS circuits, particular in complex limiting circuits (e.g. limiters, build up in multiple stages) during the assessment and use the STA for the determination of IS parameters rather than I-Spark or IEC 60079-25.

Ignition values for capacitive circuits derived from IEC 60079-11 Ed.6 Table A.2 and Figure A.3 are higher than those recently determined by testing with the STA, because the influence of the resistance in the IS circuit in series to the external capacitance has not been considered when these values were determined. Further investigation into clarification on the use of the ignition curves may be needed to take into account resistively limited energy in addition to the capacitive energy. WG gives the following recommendation to MT 60079-11:

- practical test with the STA (may be not necessary if the capacitance is distributed in a cable only) or

- use a mathematical model which is able to consider the energy and time constant.

Results from the “Proficiency Testing Program” of IECEx ExTAG WG10 were not discussed at this meeting. Respectfully submitted Udo Gerlach and Günter Gabriel Convenors, WG4 – Spark Test Apparatus 6th October 2016

Annex C to DE-comments on line 3468 – 3472 Annex B, B.1.2 of 31G/269/CD - Tolerances Annex C

Tolerances for B.1.2

11

Tungsten Wire length T (11)

Distance between Holder and Cadmium disc D (10)

Depth of the Groove on Cadmium disc G (2)

Conditions for the dimensions:

Minimum overlap between Tungsten wire and cadmium disk should be 0,8 mm

T > D + 0,8 mm

T < D + G

Proposal for possible Tolerances:

T 11 mm - 0%, + 8%

D 10 mm -0%, + 2%

G 2 mm - 0%, + 10%

Tmin 11 mm > Dmax 10.2 mm

Tmax 11.88 mm < Dmin + Gmin 12 mm

Annex of GB.doc

Annex GB-1 Revised 5.3 incorporating much of 9.1.1 and 9.1.2 that relates to spark ignition in general and not just STA: 5.3 Spark ignition compliance Intrinsically safe circuits shall be assessed to ensure that available spark energy is incapable of causing ignition of the explosive atmosphere at each point where an interruption or interconnection can occur. Where the structure and electrical parameters of a circuit are sufficiently well defined for its safety to be deduced from reference curves, Figures A.1 to A.6 or Tables A.1 and A.2, by the methods described in Annex A may be used. Alternatively, spark ignition testing in accordance with 9.1 shall be conducted. NOTE A circuit assessed using the reference curves and tables may cause ignition when tested using the spark test apparatus. The sensitivity of the spark test apparatus varies, and the curves and tables are derived from a large number of such tests.

For Group III, the spark ignition assessments or tests of Group IIB shall be applied. Circuits with both inductance and capacitance shall be assessed according to 9.1.5.2. Where ignition tests with the spark test apparatus are not appropriate for testing the transient energy through controllable semiconductor limitation circuits (for example, for shunt assemblies or controlled semiconductor current limiters), this transient energy shall be assessed in accordance with 9.1.5.3. For Level of Protection “ia” and “ib”, spark ignition assessment applies to any countable fault or non-countable fault that involves an earth fault or interruption or interconnection of a circuit, and to normally opening and closing contacts. EXAMPLES:

- examples of applicable countable faults are failure of separation that is greater than 1/3rd but less than the values of Table 5, or more than half but less than the values in Table 6; - examples of applicable non-countable faults are failures of internal connections, internal creepage distances, clearances, distances through casting compound and distances through

solid insulation not conforming to 6.1.2.2. or 6.1.2.3; - examples of normally opening and closing contacts are plugs and sockets, switches, pushbuttons and potentiometers.

For Level of Protection “ic”, spark ignition shall be considered for the following: – at connection facilities; – across separations less than the values specified in Table 5 or Table 7;

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