example of substation maintenance & assessment audits for training - niels inderbiethen

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Technical Report SAFE™ Audit of 3.3 & 11kV Switchoards

Substation name Customer Location

2014/01/09

Infrastructure & Cities Sector

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Table of contents 1. General information ...................................................................................................... 3

2. Chart of Medium voltage condition ............................................................................. 6

3. Summary ....................................................................................................................... 7

4. Safety ............................................................................................................................. 8

5. Visual inspection when asset in operation ............................................................... 15

6. Environmental sustainability ..................................................................................... 28

7. Maintenance recommendations ................................................................................ 29


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1. General information

Audit

Customer

Country South Africa

Location

Substation name

Asset type Audit of Siemens 11kV & 3.3kV 8BD

Type Siemens 8BD Panels 3AC / 3TL5

Serial number B4E213765

Date 2014/01/09

Remarks Audit for assessing life-time status

Auditor

Name Niels Inderbiethen

Department AFR RC-ZA IC-SG SE MCS

Telephone +27 (10) 222-7315

Fax

E-mail [email protected]

Customer data

Contact person (technical) card below

Telephone number of the contact person See below

Fax number of contact person As below

E-mail of contact person As below

Postal Code

Town

Street, No.


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Technical Information

Manufacturer Siemens

Type designation of switchgear Siemens RSA Type: 8BD 11kV 25kA with 3AC Circuit breaker & 3TL5 Contactor Trucks

Standard IEC 60298 / VDE 0670-6 (metall closed)

Year of manufacture of switchgear 1976

Substation arrangement Double busbar

Installation Indoor

Number of bays 15 (a mix of (4) ABB & rest Siemens

Number of spare bays A few may become available once plant redundancy is established

Serial numbers TBA

Air insulated metall closed switchgear Yes

Gasinsulated metall closed switchgear No

Remark The Panel is joggled onto an ABB panel of 4 tiers & shares the busbar system

General remarks by auditor It should be noted that some of these panel tiers seem to have come from different locations and are rather "fitted" (diferent colours of panel parts fitted together)

General remarks by customer There have been previous explosions on the board and there seems to have been a robbery of the copper on this panel the week before conducting the audit - all open & exposed copper was removed from panel leaving a very unsafe running condition

Rated voltage 12 kV

Rated lightning impulse withstand voltage 95 kV

Control voltage (DC/AC) DC

Control voltage 110 V

Rated short circuit breaking current 25 kA

Maximum busbar current 2000 A

Rated current supply 2000 A

Rated current feeder 1600 A


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Historical Information

Years of operation since first commissioning 36-40 years

Are maintenance reports available? No

Have circuit breakers been modified? Yes

When? Various occasions

Remarks Some circuit breakers are from other simillar panels from elswhere in Sasol


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2. Chart of Medium voltage condition (Weighted average of evaluated attributes. 0: very good --> 100: bad)

0

20

40

60

80

100Battery system

Busbars

Bushings

Circuit breaker

Condition of building

Current transformer

Grounding

Load-break switchLow voltage switchgearMeasurement

Metering

Natural

Ageing

Post insulators

Protection and

secondary system

Safety

Switchgear accessories

Voltage transformer

Maintenance requirements

Natural Ageing ████ Very critical attributes were found. Immediate action required.

Safety ████ Very critical attributes were found. Immediate action required.

Condition of building ████ Critical attributes were found. Repair or replace as soon as possible.

Switchgear accessories ████ Very critical attributes were found. Immediate action required.

Circuit breaker ████ Very critical attributes were found. Immediate action required.

Load-break switch ████ Very critical attributes were found. Immediate action required.

Grounding ████ Very critical attributes were found. Immediate action required.

Post insulators ████ Very critical attributes were found. Immediate action required.

Bushings ████ Very critical attributes were found. Immediate action required.

Busbars ████ Very critical attributes were found. Immediate action required.

Current transformer ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).

Voltage transformer ████ Very critical attributes were found. Immediate action required.

Metering ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).

Measurement ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).

Prot & Secondary system ████ Very critical attributes were found. Immediate action required.

Low voltage switchgear ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).

Battery system ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).


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3. Summary

The condition of the panels can be seen in the pictures provided, the board would require to be cleaned and refurbished if wanted to be permanently left installed and still utilized. We would recommend a few procedures followed to ensure the safety of the existing equipment, a fully detailed compilation may be submitted with quotation upon request. These are more cost effective repair suggestions such as retro-fitting to vacuum, cleaning, facilitating remote operation & repair of any water leaks.

3.3kV & 11kV Panel general overview photo’s


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It would be recommended to possibly remove, clean and coat the busbars with ray-chem or resin for future protection. Breaker trucks can be retro fitted completly to vacum, wiring is still in good condition including termination points. Bus-chamber to be cleaned on surface and re-painted. Areas that show burning can be repaired by applying hay-site barriers over the effected & damaged areas. This would ensure the most cost effective manner of dealing with immediate problems and uplifting the safety and reliability factor of the whole board. It is also recommended that any redundant equipment should be considdered for removal to free up some spare space to fit new breakers & panels in the future. This could be done by possibly looking at the bus-section breaker as the split-point to one way or the other, by using cable to re-instate the connection in the trench to connect the panels again from the bus-section rear panel by cable termination to the continuation point in the existing board up to where panels are to be removed.


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3.3kV Panel photo’s Panel 1 (only 1 tier)


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11 kV (ABB – Sach‘e) - Panel photo’s – (note numbers differ

ABB Panel Joggle to Siem ABB 11 kV Panel -02 ABB 11 kV Panel -03 ABB 11 kV Panel -04 ABB 11 kV Panel -01


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SIEMENS - 11 kV Panel photo’s

11 kV Panel 01 11 kV Panel 02 11 kV Panel 03 11 kV Panel 04 11 kV Panel 05


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11 kV Panel photo’s (continued)



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11 kV Panel photo’s (continued)



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4. Safety

Staff protection

(NNB – It is important to state that these problems will no longer exist after retro-fitting)

Personnel protection insulation DIN VDE 0106 (IEC 60990)

Personnel protection insulation DIN VDE 0106 (IEC 60990) Bad, big impact deficiencies

Remark Equipment is in a very bad mechanical and functional condition - trips can no longer be fully relied upon

Operational safety DIN VDE 0101 (IEC 61936)

Load-break switch instead of disconnector Not applicable

Remark n/a

Switchgear interlocking unit Bad, big impact deficiencies

Remark Some Circuit Breaker Operating mechanism safety interlocks for the door to prevent opening under operating conditions seem to have a lot of play and replacement is advised

Operation from a safe distance Bad, big impact deficiencies

Remark Under the present condition operation is ONLY advised from a safe distance unless FULL Fire Protection is worn by operator and assistant - all others to leave the station

Installation of suitable electro-sensitive protective equipment Bad, big impact deficiencies

Remark There is literally a bird nest of wire and tangled cables under the full length of the panel inside the Cable Trench –some neatening of the cables & strapping of loose wiring is advised

Country-specific standards

Country-specific standards considered? Yes

Which kind of? The compliance to regulations for safe operations of Electrical plant and equipment need to be re-assessed in this substation due to the recent copper theft, which is also what has caused the untidy trenches etc.


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5. Visual inspection when asset in operation

Environment

Altitude of site 1000 m up to 2000 m

Ambient temperature range - 5 °C up to + 40 °C

Current temperature on substation site 28

Quality of the ambient atmosphere Dirty

Installation in seismic zone No

Remark the coal dust is visible on insulators in busbar chamber & any moisture from the cable-way may now pose serious electrical flashover threats

Building

outside

Ventilation, air exhaust louver, pick safety Bad, big impact deficiencies

Remark High humidity - no heaters are present in board

Pressure relief building Bad, big impact deficiencies

Remark The building is also not pressurized

inside

Aisle widths sufficient / escape route available good, no defects

Remark none

Floor, floor plates Bad, big impact deficiencies

Remark Some of the floor plates were removed during the cable theft incident as per photos

Cable basement, cable vault Bad, big impact deficiencies

Remark Wiring & cabling has been bundled up

Electro-installation, lighting Medium, insignificant deficiencies

Remark Seems ok - however a water leak was noted from the ceiling all the way down the wall by run-off tracks on the paintwork

Pollution, Humidity Bad, big impact deficiencies

Remark Coal dust - constant 90%+ permanent humidity – due to no heaters


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Switchgear accessories

Isolating protective plates VDE 0682-552 Bad, big impact deficiencies

Remark some have been stuck together with insulation tape

Guide strips for protective plates Bad, big impact deficiencies

Remark many guide plates have been damaged during the copper theft incident and some insulation plates have been broken

Grounding accessories VDE 683T100 Bad, big impact deficiencies

Remark All the copper external, on, or mounted to any switchgear or any bridged holding points was removed during theft - however this was immediately rectified by Client

Voltage tester VDE 682T411 Bad, big impact deficiencies

Remark The Voltage tester brought to test for isolation was not functional and could not be used

Fuse tongs VDE 681T3 Not applicable

Remark none

SF6-Maintenance unit available No


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Switching devices

First type of circuit breaker

Are circuit breakers installed? Yes

Principle of interruption Minimum oil

Number of circuit breakers 5 3AC type Circuit breakers and 3 type 3TL5 Vacuum contactors mixed in 8BD 11/3.3 kV Panel

Type designation of circuit breaker Various - but mostly feeders to plant transformers

Year of manufacture of circuit breaker 1976



Serial numbers 31175637

Type of operating mechanism Manual operating mechanism

Type of bodywork Trolley



Number of operations in accordance with the operation counter high

Diagnosis Bad, big impact deficiencies

Remark mechanisms of all circuit breakers are at the end of their lifecycle - trip failure experienced during inspection - loose adjustment & serious wear determined as cause / corrosion & rusted sliding surface issues found


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Second type of circuit breaker


Principle of interruption Vacuum

Number of circuit breakers 3

Type designation of circuit breaker Siemens 3AC & 3TL5

Year of manufacture of circuit breaker 1976



Serial numbers as per individual breakers

Type of operating mechanism Magnet drive

Type of bodywork Trolley



Number of operations in accordance with the operation counter high


Remark Corrosion & rust (all seem quite affected by this) however we must make mention that Sasol Nitro has 6 spare Contactors recently all refurbished - (as an emergencycontingent for spares)


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Third type of circuit breaker


Principle of interruption Vacuum

Number of circuit breakers 4

Type designation of circuit breaker ABB / SACHE HA1/2c-17-12-20

Year of manufacture of circuit breaker Not Shown

Years of operation since first commissioning <20 years

Manufacturer ABB

Serial numbers ME063100

Type of operating mechanism Motor operated mechanism

Type of bodywork Plug - in board



Motor voltage (DC/AC) DC

Motor voltage 125 V

Number of operations in accordance with the operation counter low

Diagnosis Medium, insignificant deficiencies

Remark The Sache breakers still look relatively in a good state, but the life expectancy may be crippled by dust, dirt & moisture if heaters are not present

Forth type of circuit breaker

Are circuit breakers installed? No

Remark none


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First type of load break switch

Are load break switches or fuses installed? Yes

Design Fuse mounting


Number of load-break switches none (fitted are only fuses with striker pin mounting brackets on all contactor feeders)

Type designation of load break switch none

Year of manufacture of load-break switch none



Serial numbers not visible on all


Control voltage Other...

Which kind of control voltage? 30V DC

Number of operations in accordance with the operation counter N.A.


Remark Mainly affected by corrosion


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Second type of load break switch

Are load break switches or fuses installed? No

Remark None

First type of disconnector

Are disconnectors installed? No

Remark None

First type of earthing switch

Are earthing switches installed? Yes

Make proof earthing switch Yes


Number of earthing switches not determinable

Type designation of earthing switch cable earth switches if fitted

Year of manufacture of earthing switch same as panel


Manufacturer Other...

Manufacturer Siemens Italy

Serial numbers not determinable

Diagnosis Cannot be determined – (these will be internally fitted if present)

Second type of earthing switch

Are earthing switches installed? No

Earthable fixpoints

Are earthable points installed? No


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Components

Post insulators

Are post insulators installed? Yes

Type Cast resin


Condition Dirty

Remark Showing signs of hollow bubbling on surface - meaning they will start absorbing more moisture as time goes by - carbon & moisture is a dangerous combination & can become semi-conductive & flash-over

Bushings

Are bushings installed? Yes

Type Cast resin


Condition Damaged

Remark some through-bushings from the C/B compartment into the live busbar chamber are broken or damaged

Busbars

Are busbars installed? Yes

Insulation Air insulated

Material Copper

Cross section 2 by 10


Remark Bad corrosion / or carbon burning from prior explosions has discoloured & turned the copper black - insulators are covered in soot

Current rails

Are current rails installed? No


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Current transformer incoming feeder

Are current transformers installed? Yes

Design Post insulator instrument transformer

Insulation Cast resin

Type Current Electric

Year of manufacture assumed same as panel

Manufacturer Current Electric

Quantity several spread out among feeders, incomers, etc.

Serial numbers Name plates are taped to the LT compartment walls

Core data of 1st core (Example: 200/1 A, 15 VA, 5 P 20) as plates

Core data of 2nd core (Example: 200/1 A, 15 VA, 5 P 20) as plates

Core data of 3rd core (Example: 200/1 A, 30 VA, 1 Fs 5) as plates

Core data of 4th core (Example: 200/1 A, 15 VA, 5 P 20) as plates


Condition of current transformers Very dirty

Remark The CT's are old, however they may still remain operational for a long time, life-expectancy is cut by moisture problem without heaters

Current transformer outgoing feeder

Are current transformers installed? No


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Voltage transformer

Are voltage transformers installed? Yes

Design Conventional

Type 8BD - VT Ruksak

Year of manufacture same as panel


Quantity 2 on the 11kV Board

Serial numbers not visible during operation

Primary voltage (Example: 110 000/√³ V) 11000

Secondary voltage of the measurement winding (Example: 110/√³ V) 110

Earth fault winding Yes

Class standard 11kV VT

Voltage factor (Example: 1.9 * Un, 4 h) standard


Condition of voltage transformer Very dirty

Remark VT's are also advised to be checked and serviced regularly, especially from the coal / carbon residue

Surge Arresters

Are surge arresters installed? No

Over voltage limiter

Are overvoltage limiters installed? No

Secondary Systems

Metering

Is a counting facility available? Yes

Manufacturer various as per each panel LT relays mounted in relay compartment

Type also various


Remark The relays need to be checked & maintained annually, or it must be determined when last relay testing was conducted & the time for next testsshould be noted – testing of old protection is very important.


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Measurement

Is a measuring facility available? Yes

Manufacturer Various

Type KWH Relays


Remark The attention claim above refers to the need to check & maintain relays annually, or determining when last relay testing was conducted & the time for next tests

Protection

Are protection devices installed? Yes

Protection electromechanical

Distance Protection

Distance Protection No

Differential Protection

Differential Protection No

Over current protection

Over current protection Yes

Manufacturer Other

Manufacturer various

Type Over-current & Earth-fault


Remark The earth-fault protection was non functional at the time of conducting the audit, due to all the earth bars having been loosened and removed by theft -this was all re-instated again in the same day by the client.

Busbar protection

Busbar protection No


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Low voltage switchgear

Are low voltage switchgear installed? Yes


Type LV 400V Isolators & feeder circuit MCB's

Year of manufacture unknown

Personnel protection insulation in accordance with DIN VDE 0106 (IEC 60990)

Yes


Remark The equipment is operational although old

Battery system

Do DC auxiliary supply equipment exist? Yes


Type various

Year of manufacture various


Remark equipment operational, it should also be tested once annually & any faulty units should be replaced

Compressed air generation

Is a compressed air generation available? No

Other

Other none

Documentation

Documentation

Documentation Not available/not installed

Remark Only the single line drawing was found in the substation, a full set of drawings should usually be available and checked that they are up to date


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Files

Attach file 1 All ABB Panel Pics.ZIP

Attach file 2 All Zips here combined for Report.rar

Attach file 3 Siemens 8BD Panel 01.zip












Attach file 15 13_14&15.zip

Audit Configuration

The first level of the audit is complete. How do you want to proceed? -The customer requests FUTURE consulting or thorough investigations / recommendations for retro-fits


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6. Environmental sustainability Conclusion

Important status parameters of the tested system indicate high risk of environmental hazard. Please observe the maintenance recommendations.

The board has suffered many explosions and requires a good cleanout and repainting or re-spraying. The busbar chamber needs urgent attention as carbon & coal dust have collected on all bars. There also seem to be a few connections where tape is coming loose and these are starting to find their way close to other phases or earth potential points. Many smaller problems exist as can be seen via the wiring in cable trenches and melted truncking that should be cleaned, neatened and replaced. This work could easily be undertaken in a very quick manner to tick off all problem areas. Circuit breaker mechs must be sprayed with lubrication every month from now going forward.


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7. Maintenance recommendations Safety Personnel protection insulation DIN VDE 0106 (IEC 60990) - The located weakpoints regarding personnel protection insulation have to be removed immediately Operational safety DIN VDE 0101 (IEC 61936) - The located weakpoints have to be removed immediately Natural Ageing - The actual ambient conditions may require additional maintenance works Condition of building outside - The located weakpoints on the building have to be removed immediately inside - The located weakpoints on the building have to be removed immediately - The located weakpoints on the building have to be removed on the next occasion Switchgear accessories - Exchanging equipment (start planing for older equipment exchanges) - Exchanging equipment (Check enough critical spares are still on hand to have sufficient time to implement) - Exchanging equipment (after anual testing, if found faulty, exchange with new as necessary or advised) - Exchanging equipment (circuit breakers can easily be exchanged (oil fire hazzard) rather for new vacuum) Circuit breaker First type of circuit breaker Maintenance of all the existing 3AC minimum-oil breaker operating mechanism, regular checks will be required (at least once a month) to ensure safer operation capability of the tripping coils as their operation has become hindered, leading to the posibility of an extensive delay in the effected breaker trip time. Should this scenario occur at the time of an electrical system fault, it may not trip in time &flash to the weakest point. Second type of circuit breaker - Maintenance of operating mechanism.


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Post insulators - Maintenance of insulators. Bushings - Maintenance of insulators. Busbars - Maintenance of insulators. Current transformer Current transformer incoming feeder - Maintenance of the equipment Voltage transformer - Maintenance respectively repair of the instrument transformer 1

Please note: This audit report summarizes only the existing condition of the customer’s electrical equipment and system at the time when the audit was performed. Please note that any subsequent changes of the equipment, system or equipment’s operation may cause inconsistency between the report’s summary and the subsequently changed conditions. Siemens cannot be held liable for such inconsistency. Charts, diagrams and graphics in this report are merely illustrations to summarize and to provide an overview of the condition of the customer’s electrical equipment and system at the time the audit was performed. No conclusions should be made and no further measures should be taken based exclusively on the graphic presentations included in this report. Siemens shall not be liable if the information included in this report is not handled or otherwise used with the necessary expert knowledge and thereby damage of any kind is caused. Siemens shall not be held liable for technical developments which supersede or invalidate the information in the report, if these could not have been reasonably known or identified prior to the time when the audit was performed.

example of substation maintenance & assessment audits for training - niels inderbiethen

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