7 696 gas valve proving system ldu11 - fm franklin

Landis & Staefa CC1N7696E April 15, 1997 1/17

7696

Gas Valve Proving SystemVALVEGYR®

LDU11...Series ...A...

The LDU11... gas valve proving system is designed for use in gas-fired plantequipped with two safety shutoff valves. During each startup cycle, the control unitautomatically programs the valve proving test and, in the event of a leak, preventsburner startup.

The LDU11... control unit is designed to provide automatic gas valve proving (leakagetest) based on the pressure proving principle. It is for use in gas-fired plant with or withoutvent pipe to the atmosphere. For plants without vent pipe, where DIN/DVGW regulationsapply, refer to the hints given on «Connection examples with vent pipe to theatmosphere».

Gas valve proving is initiated automatically with every burner startup using one or twostandard pressure monitors, either

– prior to burner startup,– during the pre-purge time, if it lasts at least 60 s,– immediately after the controlled shutdown, or– on completion of the burner control's control program, e.g. on completion of the post-

purge time

The valve proving test is based on the two-stage pressure proving principle: first, thevalve on the mains side is tested by evacuating the test space and by monitoring theatmospheric pressure in it. Then, the valve on the burner side is checked by pressurizingthe test space and by monitoring the gas pressure. If the pressure increases excessivelyduring the first test phase (Test 1), or decreases excessively during the second testphase (Test 2), the control unit inhibits burner startup and goes to lockout. In that case,the lockout reset button lights up to indicate the fault. Remote indication of the fault isalso possible. A program indicator, which stops whenever a fault occurs, indicates whichof the two valves is leaking.

The LDU11... can be reset either on the unit itself or with an electric remote resettingdevice.

ISO 9001

Use

2/17 CC1N7696E April 15, 1997 Landis & Staefa

The control unit is of plug-in design. Housing and plug-in base are made from impact-proof and heat-resistant plastic material.The housing accommodates:

– The synchronous motor of the sequence switch complete with gear train and stepaction sequence switch

– The camshaft with 15 non-adjustable cams– The program indicator at the head of the camshaft– One main and one auxiliary relay– The lockout relay which can be electrically reset from a remote location and which

provides the functions «Lockout» and «Resetting»– The unit fuse with a spare fuse

All electrical components are interconnected via printed circuits.

The plug-in base carries the following terminals:

– 24 connection terminals– 2 auxiliary terminals (nos. «31» and «32»)– 3 earth terminals– 3 neutral terminals (prewired to terminal 2, the neutral input)

The following knockout holes are available for the cable entry:

– 14 knockout holes for the cable entry by means of cable glands, 8 at the side and 6 atthe bottom of the base

– 6 threaded knockout holes at the side for cable entry glands Pg11

Plug-in base and terminals are designed such that the erroneous plugging in of a unit withthe same housing, which is not suited for use with the relevant burner, is madeimpossible.

Visible in the transparent lockout reset button, the program indicator informs service staffabout the programming sequence, the type of fault and the point in time the faultoccurred, using easy-to-remember symbols.

Control unit for gas valve proving, without base

– For AC 220-240 V, 50-60 Hz LDU11.523A27– For AC 100-110 V, 50-60 Hz LDU11.523A17

Plug-in base AGM11

Mains voltage AC 220 V -15 %...240 V +10 % Perm. current rating of control terminalsAC 100 V -15 %...110 V +10 % 4 A to VDE 0660 AC3

Mains frequency 50 Hz -6 %...60 Hz +6 % Required switching capacityof pressure switch «DW» 1 A min., AC 250 V

Power consumption- during the test 3.5 VA Mounting position optional- during burner operation 2.5 VA Degree of protection IP40

Prefuse (externally) T16/500 V WeightUnit fuse T6,3H250 V to IEC 127 − control unit approx. 1000 gRadio interference protection N to VDE 0875 − base approx. 165 g

Perm. input current at terminal 15 A continuous to VDE 0660 AC3

Environmental conditions: CE conformity- Transport IEC721-3-2 According to the directives of the European Community Climatic conditions class 2K2 Electromagnetic compatibility EMC Temperature -50...+60 °C 89/336 EWG include. 92/31 EEC Humidity < 95 % r.h. Gas appliance directive 90/396 EEC Mechanical conditions class 2M2 Emissions EN 50081-1- Operation IEC721-3-3 Immunity EN 50082-2 Climatic conditions class 3K5 Temperature -20...+60 °C Humidity < 95 % r.h.Condensation, formation of ice and influence of water are not permitted.

Mechanical design

Ordering

Technical data


To carry out the first phase of the valve proving test, called «Test 1», there must beatmospheric pressure in the length of pipe between the two valves to be tested. In plantswith a vent to the atmosphere, this pressure is available if the valve proving test isconducted prior to or during the pre-purge time. In plants without a vent pipe,atmospheric pressure is made available as the control unit opens the valve on the burnerside during the time «t4». If the valve proving test is performed after the operation of theburner, the valve on the burner side after the controlled shutdown can be kept open until«t4» has elapsed, thus reducing the pressure in the test space and making certain its gascontent is burnt off in the combustion chamber during the post-purge time. A prerequisitefor this procedure is an appropriate control program of the burner control as provided byLandis & Staefa burner controls type LFE..., LFL..., LGK.... or LEC....

The test space is closed off after it has been evacuated. During the first test phase(Test 1) which follows immediately, the control unit checks if the atmospheric pressure inthe test space is maintained using the pressure monitor. If the valve on the mains side isleaking, causing the pressure to rise above the switching point of the pressure monitor,the control unit initiates an alarm and goes to lockout. The program indicator then stopsand indicates «Test 1».

If the pressure does not increase because the valve closes correctly, the control unitimmediately programs the second test phase (Test 2). To do this, the valve on the mainsside is pressurized («filling» of test space). During the second test phase, the pressuremay not fall below the switching point of the pressure monitor due to a leak of the valveon the burner side. If it does, the control unit goes to lockout again, thus inhibiting burnerstartup.

On the successful completion of the second test phase, the control unit closes the internalcontrol loop between terminals 3 and 6 (circuit path: terminal 3 - contact «ar 2» -terminals 4 and 5 - contact III - terminal 6). This control loop is usually included in the startcontrol loop of the burner control.

After the control loop has been closed, the programming mechanism of the control unitreturns to its start position where it switches itself off. During these «idle steps», theposition of the control contacts of the programming mechanism remains unchanged.

Mode of operation


When the unit goes to lockout, the programming mechanism stops and also the positionindicator fitted to the spindle of the mechanism. The symbol that stops above the readingmark not only indicates during which test phase lockout occurred, but also after howmany programming steps within the test phase (1 step = 2.5 seconds).

Meaning of symbols:

Start position = operating position

In plants without a vent valve: evacuation of test space through opening of thevalve on the burner side

«Test 1» with atmospheric pressure (valve proving test on the mains side)

Filling the test space through opening of the valve on the mains side

«Test 2» with gas pressure (valve proving test on the burner side)

Idle steps until programming mechanism switches itself off

Operating position = start position for the next valve proving test

In the event of lockout, all terminals receiving voltage from the control unit are de-energized, except terminal 13, which is used for lockout indication.

After the unit has been reset, the programming mechanism automatically returns to itsstart position and immediately reprograms a new valve proving test.

Note: do not press the reset button for more than 10 seconds.

A power failure prior to evacuating the test space does not cause the program sequenceto change.

If a power failure occurs after the evacuation, the valve proving test will not be continuedwhen power is restored, but the programming mechanism first returns to its start positionto reprogram the complete proving test.

Program and lockoutindicator

Test 1

Test 2

Control program after apower failure


Calculation of leakage rate escaping from a length of pipe

where:

QLeck in dm3/h Permissible leakage rate in dm3 or liters per hour

PG in mbar Overpressure in pipe section between the valves to be tested, at the beginningof the test phase

PW in mbar Overpressure set at pressure monitor DW(usually set to 50 % of the gas mains pressure)

Patm in mbar Absolute pressure (1013 mbar normal pressure)

V in dm3 Volume of test space confined by the valves to be tested, including the space inthe valves themselves

tTest in s Duration of proving time

PG = 30 mbar

PW = 15 mbar

Patm = 1013 mbar Any valve leakage rate exceeding 20 l/h causes the control unit to go to lockoutV = 10.36 dm3 Any valve leakage rate exceeding 20 l/h causes the control unit to go to lockout

tTest = 27.5 s

Note: the volume of pipe section V between the gas valves to be checked andoverpressure Pw set on pressure monitor «DW» must be selected such that themaximum permissible gas leakage rate QLeck will not exceed the rate specified inthe local regulations.

t4 5 s Evacuation of test spacet6 7.5 s Interval from start to energizing of main relay «AR»t1 22.5 s First test phase with atmospheric pressuret3 5 s Filling the test spacet2 27.5 s Second test phase with gas pressuret5 67.5 s Total duration of valve proving test to the enabling of the burnert20 22.5 s Running time of programming mechanism until it switches itself off in the

operating = start position («idle steps»)

QLeck=

(PG -Pw t TestPatm x

x x

Example

Control program


A, A1, A2 Gas valves controlled to empty the test spaceAL Alarm signal «Leaking valve»AR Main relay with contacts «ar...»AS Built-in fuseB Gas valve controlled to fill the test spaceBR Lockout relay with contacts «br...»C Vent valve, normally open; closed during valve proving test from the beginning of «Test 1»DW Pressure monitor for valve proving test

(does not replace the gas pressure monitor used to signal lack of gas)E Safety shutoff valve, normally closed; optionalEK... Lockout reset buttonEK2 Remote lockout reset buttonGP Gas pressure monitor (for lack of gas)HR Auxiliary relay with contacts «hr...»L1 Built-in lockout warning lampLDU Control unitLP Air pressure monitorM... Fan (M2: pre- and post-purge)R Control thermostat or pressurestat, e.g. boiler control thermostatRB Pipe orifice, its diameter must be determined such that in the event of a leaking pilot gas

valve «A», the pilot flame cannot afterburn on completion of the 2nd safety time so that thepresence of the main flame cannot be simulated

SK Control contact (initiation of valve proving test)SM Synchronous motor of programming mechanismT Delay off time relay: the time should be set to approx. t16 (t7 min. ...t10 max.) of the burner

controlW Limit thermostat or pressure monitor

1) Do not press EK for more than 10 seconds2) Expanding flame or interrupted pilot burner operation

Connection diagram

M~

L

EK2

18 1

SK1)

AS ar2

3 4 5

III

6

a b

I

8

a b

V

10 12 19 23 20

a b a b

XI hr1

22 21 24

hr2 HR

ba

XIII

a b

IXar1

br1

IV

15 14

16 17

P GP

DW

Atm. Gas VII

b a

VIII

a bar3

b aVI

AR

br2

BR

L1EK1

1)

13

ALN

2 7 9 11

SM

LDU11

7696a15/0695

Legendfor the entire data sheet


• • The electrical wiring must comply with local and country-specific standards andregulations!

• The LDU11... must be completely isolated from the mains before performing anywork on it!

• The LDU11... is a safety device. It is therefore not permitted to open, interferewith or modify the unit!

• Check wiring carefully before putting the unit into operation!

• Check all safety functions when putting the unit into operation or after replacinga fuse!

• Ensure protection against electric shock hazard on the unit and at all electricalconnections through appropriate mounting!

• Electromagnetic emissions must be checked from an application point of view!

• The regulations and standards covering the specific application must beobserved!

• All installation and commissioning work must be carried out by qualifiedpersonnel!

• • In the geographical areas where DIN standards are in use, the installation mustbe in compliance with VDE requirement, particularly with the standards DIN/VDE0100 and 0722!

• • Condensation and ingress of humidity must be avoided!

• • Ignition cable must always be laid separately, observing the greatest possibledistance to other cables!

Sequence diagram

Warning notes


Connection examples with vent pipe to the atmosphere using burner control LFI7...

For other connections, refer to the wiring diagram of the burner control.

Proving test prior to burner startup Proving test following immediately the controlled shutdown

Connection examples with vent pipe to the atmosphere using burner control LFM1...



LDU11

hr2

N

N

1415

18 1

EK2

2

1716

3

ar2 III

54DW

BE

11

hr1XII

7

V

9

8 1210 2319 206

LC

N W

R

PGP

LFI7..., S.03 1

N

A

M

34

AL

22

13N

2421

LP

5

7696a17/0695

LDU11

hr2

LP

GP

N

1415

18 1

EK2

2

17

16

3

ar2 III

54DW

BE

11

hr1XII

7

V

9

8 1210 2319 206

M

NN

C

W

R

L

51 LFI7..., S.03

N

A

34

AL

22

13N

21 24

7696a16/0695

N

DW

L

LFM1...

LDU11

22

A2

GP E C

17

163

ar2 III

54

15 14

18

EK2

1

B

hr2

11

hr1XI

12

V

9

10

I

7

86

2

23 2019

RW

310

N

A1

N

LP

M

N

874 5

AL

13N

21 24

9

7696a18/0695

L

LDU11

hr2

A1

E

N

6

2

DW

17

16

15

18 1

ar2

4 5

14

3

EK2

III

BC

hr1

23 20198

7

V

9

10 12

XI

11

I

LP

R

P

GP

W

LFM1... 10 34

A2

N

M

N

5 8

AL

13N

242122

N

7

7696a19/0695


Connection examples with vent pipe to the atmosphere using burner control LGB2.../3.../4...


Proving test prior to burner startup

Proving test following immediately the controlled shutdown

Installations with vent pipe to the atmosphere

LDU11

17

DW

2

C

54

hr1

GP231116

15

EB

6

IIIar2

3

R/W

N

1

12LGB2.../3.../4...

HL

hr2

XI

2014 1912 22

53 4

A2A1M

N

AL

13

2421

10

7696a05/0595

N

L

LDU11

22

542

C

hr1

7

B

11

E

12

P

III

11614 15

DW

ar2

17 3

LGB2.../3.../4...

H

6hr2

19 23 20

I

8 12

XI

R/W

A2 A1

5

GP

3

M

N

13

AL

21 24

4

7696a06/0595

GPE

C

B

DW

LDU

AA2A1

C

DW

LDU

BGP

E

7696s01/0695


Connection examples with vent pipe to the atmosphere using burner control LFE, LFL, LGK orprogramming unit LEC...


Proving test prior to burner startup Proving test during pre-purge time (60 s min.)

Valve proving with two pressure monitors

DWG Pressure monitor for the gas valve proving test with gas pressure. This pressure monitors must be set to the minimum gas pressurepermitted during the proving test. If this pressure is not reached during the test, the control unit goes to lockout.

DWA Pressure monitor for the gas valve proving test with atmopheric pressure. This pressure monitor must be set to the maximum gas pressurepermitted during the proving test with atmospheric pressure. If this pressure is exceeded during the test, the control unit goes to lockout.

DWG and DWA must be overload-proof up to the gas pressure level.

Installations with vent pipe to the atmosphere

N

LDU11

hr2

GP E C B

5

W

1415

618 1 4

ar2 III

5

EK2

17

163

8

4

9LFE1LEC1

LFL1...LGK16...

R

11

19

hr1XI

202312

9

V

10

7

8

I

2

N

5°/10°°

18°/17°°

A

AL

13N

242122

7696a07/0796

DW

2)

2)

N

LDU11

hr2

GP CE B

4

14

W

1415

618 1 3

ar2 III

5

EK2

17

164

LP

8 18 19

4

9

5 12 13

LFE1LEC1

LFL1...LGK16...

R

11

201912

hr1XI

23

N

9

10

V

7

8

I

2

5°/10°°

18°/17°°

A

AL

22

13

2421

N

7696a08/0796

DW

2)

2)

16

17

DWG DWA 15

7696a09/0796


Connection examples with vent pipe to the atmosphere using burner control LFE,LFL, LGK or programming unit LEC...

Proving test both during the pre-purge time (60 s min.) and immediately after thecontrolled shutdown in plants with a vent pipe to the atmosphere. On delay of relay d> 2 s.


N

LDU11

hr2

GP C

1415

18 1EK2

217

166

III

53

ar2

4

BE

11

201912

hr1XI

238

I

7

10

V

9

14

W

2

d

LFE1LEC1

LFL1...LGK16...

18 199

12 134

LP

8

5

RN

4 5°/10°°

18°/17°°

A

AL

22

13

2421

N

7696a10/0796

DW

2)

2)

LDU11

hr2

GP C

N

BE

6

W

1415

18 1

17

16III

53

ar2

4

2

EK2

4

LFE1LEC1

LFL1...LGK16...

8

RN

11

201912

hr1XI

23

I

7

10

V

9

8

5°/10°°

18°/17°°

A

9

5

AL

7696a11/0796

22

13

2421

N

DW

2)

2)


Connection example without vent pipe to the atmosphere (suitable for allcountries) using burner control LFE, LFL, LGK or programming unit LEC...

Proving test following immediately the controlled shutdown in plants without ventpipe. Valve «A» or «A1» remains open after the controlled shutdown until the start of thefirst test phase is reached in order to evacuate the test space and to burn off the gascontained in it in the combustion chamber during the after-burn time.


DWG Pressure monitor for the gas valve proving test with gas pressure. This pressure monitors must be setto the minimum gas pressure permitted during the proving test. If this pressure is not reached duringthe test, the control unit goes to lockout.

DWA Pressure monitor for the gas valve proving test with atmopheric pressure. This pressure monitor mustbe set to the maximum gas pressure permitted during the proving test with atmospheric pressure. If thispressure is exceeded during the test, the control unit goes to lockout.


Installations without vent pipe to the atmosphere

LDU11

hr220

EGP

N

BA

R

1415

18 1

17

163

ar2

4

2

EK2

5

III

6

4

LFE1LEC1

LFL1...LGK16...

8 9

W

5

11

1912

hr1XI

23

I

7

8

V

9

10

M2N

5°/10°°

18°/17°°

17

7

AL

7696a12/0796

13

24

N

2122

3

6

DW

2)

2)

16

17

DWG DWA 15

7696a09/0796


Connection examples without vent pipe to the atmosphere using burner control LFI7...(cannot be used where DIN/DVGW and TRD412 regulations are in force)

For other connections, refer to wiring diagram of the burner control.


Connection examples without vent pipe to the atmosphere using burner control LFM1...



N

DW

L

LFI7..., S.03

LDU11

22

LP

EGP

1415

18 1

EK2

2

17

163

ar2

4

III

65

I

BA

hr2

hr1

9

23 2010

V XI

1912

11

8

7

W

R

M

N

51 34

AL

13N

21 24

7696a20/0695

N

LFI7..., S.03

LDU11

8

E

1415

18 1

EK2

2

1716

3

ar2

DW 4 5

III I

6

7

BA

hr2

11

hr1

19 2023

XI

12

V

9

10

L

W

R

PGP

1 4

N

M

53

AL

13

N

242122

LP

7696a21/0695

LDU11

hr2

E

N

6

2

DW

17

16

15

18 1

ar2

4 5

14

3

EK2

III

BA1

hr1

23 20198

7

XI

11

I

12

V

9

10

LLP

R

P

GP

W

LFM1... 10 34

A2

N

M

N

5 8

AL

13N

242122

7

7696a23/0695

LDU11

A2

hr2

GP EN

DW

17

16

15 14

18

EK2

1 3

ar2

4 5

III

6

2

BA

11

hr1XI

23 201912

I

7

8

V

9

10

L

RW

LFM1... 10 3 4

A1

NM

N

LP

75

AL

22

13N

21 24

N

8 9

7696a22/0695


Connection examples without vent pipe to the atmosphere using burner control LGB2.../3.../4...


Proving test prior to burner startup



N

LDU11

hr222

A1

GP

EB

N

DW

15

1 3 4

ar217

16

R/W

2

5 6

III

LGB2.../3.../4... 12

LH

9 2311

2010

hr1V XI

12 14 19

53

M A2

4

AL

13

2421

N

10

7696a13/0595

LDU11

hr222

E

N

BA1

15

ar217

16III

214

DW

PGP

LH

65431

12LGB2.../3.../4...

N

hr1

1197

202319108 12

I V XI

A2

53

M

N

AL

13

N

2421

4

R/W

7696a14/0695

GPE B

DW

LDU

AA2A1

DW

LDU

BGP

E

7696s04/0695


Connection examples without vent pipe to the atmosphere using burner control LFE..., LFL..., LGK... orprogramming unit LEC...




DWG Pressure monitor for the gas valve proving test with gas pressure. This pressure monitors must be set to the minimum gas pressure permittedduring the proving test. If this pressure is not reached during the test, the control unit goes to lockout.




LDU11

hr2

GP E

N

BA

W

1415

618 1

ar2 III

EK2

17

16

3 4 5DW

8

4

9LFE1LEC1

LFL1...LGK16...

R

11

19

hr1XI

202312

7

8

I

2 9

10

V

5

5°/10°°

18°/17°°

AL

13N

242122

7696a24/0796

2)

2)

N

LDU11

hr2

GP E BA

14

W

1415

618 1 3

ar2 III

5

EK2

17

16

4

LP

8 18 19

4

9

5 12 13

LFE1LEC1

LFL1...LGK16...

R

11

2019

hr1XI

2312

7

8

I

2 9

10

V

4 5°/10°°

18°/17°°

AL

22

13

2421

N

7696a25/0796

DW

2)

2)

16

17

DWG DWA 15

7696a09/0796


Connection examples without vent pipe to the atmosphere using burner control LFE..., LFL..., LGK... orprogramming unit LEC... and SKP70... with expanding flame burners




DWG Pressure monitor for the gas valve proving test with gas pressure. This pressure monitors must be set to the minimum gas pressure permittedduring the proving test. If this pressure is not reached during the test, the control unit goes to lockout.



The air pressure for the SKP (PL) must be sufficiently high to open the SKP70, although the burner’s air damper is closed. If this is not

observed, the LDU11... control unit will go to lockout when performing Test1


LDU11

GP E

N

BA

2

LP

W

6

1415

18 1

ar2 III

EK2

17

16DW 4 53

14

8 18 19

4

9

12 13

LFE1LEC1

LFL1...LGK16...

R

4

5

hr2

11

2019

hr1XI

2312

7

8

I

9

10

V

M

5°

18°

AL

13

2421

N

22

N

6/7

3/17

7696a27/0796

LDU11

22

GP EN

BA

2

W

6

1415

18 1

ar2 III

EK2

17

16DW 4 53

LP

14

8 18 19

4

9

12 13

LFE1LEC1

LFL1...LGK16...

R

5

4

N

hr2

11

2019

hr1XI

2312

7

8

I

9

10

V

5°

18°

T

AL

M

13

2421

N

6/7

3/17

7696a26/0796

16

17

DWG DWA 15

7696a09/0796

GP

BE

DW

LDU

A

7696A02/0796C

SKP70


Dimensions in mm

LDU11... with base AGM11...

AGM11...

Dimensions

1,5

123

7

15,5

618,9

25 25

7,5 5

15 15 15

27,5 27,5

37

7,5

103

103

7696m02/0296

5,2x6,7 40 18,5 13,5 5,7

5,7

12,81

15

25

40

51,5

12,85,7

51,5

51,513,8

13

51,540

7,5 18,9

4,4

1,5

5,2x6,75,2

32

N

31

1

2

3

4

5

6

7

8

9

10

11

1213 14 15 16 17 18 19 20 21 22 23 24

7696m01/0296

1997 Landis & Gyr Produktion (Deutschland) GmbH

7 696 gas valve proving system ldu11 - fm franklin

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