7 696

VALVEGYR®

Valve Proving System for LDU11...

automatic Shutoff Valves

The LDU11 valve proving system is designed for use with shutoff valves in
connection with gas burners and gas appliances. In the event of inadmissible
leakage, the system prevents the burner from starting up.
The LDU11 system conforms to the requirements of EN 1643 covering automatic
shutoff valves for use with gas burners and gas-fired appliances to EN 161, class A
and pressure switch to EN 1854.

The LDU11 and this Data Sheet are intended for use by OEMs which integrate the
valve proving system in their products.

CC1N7696en
Building Technologies
16.10.2018
Use

The LDU11 is designed for automatic gas valve proving (leakage test) based on the
pressure proving principle. It is for use on gas-fired combustion plant with or without vent
pipe to atmosphere. In the case of plants with no vent pipe where EN standards apply,
the notes given in «Connection examples without vent pipe to atmosphere» must be
observed.

Used in connection with 1 or 2 commercially available pressure switches, valve proving is

automatically initiated with every burner startup, either
- prior to burner startup
- during the prepurge time if it lasts a minimum of 60 seconds
- immediately after a controlled shutdown, or
- on completion of the burner control’s control sequence, e.g. at the end of the
postpurge time

The valve proving test is based on the 2-stage pressure proving principle:
1. The valve on the mains side is tested by evacuating the test space and by monitoring
the atmospheric pressure in it.
2. The valve on the burner side is checked by pressurizing the test space and by
monitoring the gas pressure.

If the pressure increases excessively during the first test phase called «Test1», or
decreases excessively during the second test phase called «Test2», the LDU11. will
inhibit burner startup and initiate lockout. In that case, the lockout reset button will light up
to indicate the fault. Remote indication of the fault is also possible. A program indicator,
which stops whenever a fault occurs, indicates which of the valves is leaking. The LDU11
can be reset either on the unit itself or via an electric remote reset facility.

Warning notes

To avoid injury to persons, damage to property or the environment, the following

warning notes must be observed.

Do not open, interfere with or modify the control unit.

 All activities (mounting, installation and service work, etc.) must be carried out by
qualified staff
 Before making any wiring changes in the connection area, completely isolate the
plant from mains supply (all-polar disconnection). Ensure that the plant cannot be
inadvertently switched on again and that it is indeed dead. If not observed, there is a
risk of electric shock hazard
 Ensure protection against electric shock hazard by providing adequate protection for
the valve proving system’s connection terminals
 Each time work has been carried out (mounting, installation, service work, etc.),
check to ensure that wiring is in an orderly state
 Press the lockout reset button only manually (applying a force of no more than 10 N)
without using any tools or pointed objects
 Do not press the lockout reset button on the unit or the remote reset button (input
terminal 18) for more than 10 seconds, as a longer period would damage the lockout
relay inside the unit
 Fall or shock can adversely affect the safety functions. Do not put such units into
operation, even if they do not exhibit any damage

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Mounting notes

 Ensure that the relevant national safety regulations are complied with
 Install switches and fuses in accordance with local valid regulations
 Ensure that the maximum permissible current load for the connecting terminals is not
exceeded
 The insulation on internal wiring which is subjected to the mains voltage must
withstand the electrical stress occurring during correct use

Installation notes

Live and neutral conductors must not be interchanged.

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Standards and certificates

Applied directives:
 Low-voltage directive 2014/35/EU
 Directive for pressure devices 2014/68/EU
 Gas Appliances Regulation (EU) (EU) 2016/426
 Electromagnetic compatibility EMC (immunity) *) 2014/30/EU
*) The compliance with EMC emission requirements must be checked after the valve monitoring system is
installed in the equipment

Compliance with the regulations of the applied directives is verified by the adherence to
the following standards / regulations:
 Safety and control devices for gas burners and gas burning DIN EN 1643
appliances - Valve proving systems for automatic shut-off
valves
 Automatic electrical controls for household and similar use DIN EN 60730-2-5
Part 2-5:
Particular requirements for automatic electrical burner control
systems

The relevant valid edition of the standards can be found in the declaration of
conformity!

 Note on DIN EN 60335-2-102

Household and similar electrical appliances - Safety - Part 2-102:
Particular requirements for gas, oil and solid-fuel burning appliances having electrical
connections.
The electrical connections of the LDU11 and the AGM comply with the requirements of
EN 60335-2-102.

EAC Conformity mark (Eurasian Conformity mark)

ISO 9001:2015
ISO 14001:2015
OHSAS 18001:2007

China RoHS
Hazardous substances table:
http://www.siemens.com/download?A6V10883536

Certified complete with plug-in base:

Type

LDU11.323A17 --- ● ● --- ●

LDU11.323A27 --- ● ● --- ●
LDU11.523A17 ● --- ● ● ---
LDU11.523A27 ● --- ● --- ---

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Life cycle
LDU11 has a designed lifetime* of 250,000 burner startup cycles which, under normal
operating conditions in heating mode, correspond to approx. 10 years of usage (starting
from the production date given on the type field). This lifetime is based on the endurance
tests specified in standard DIN EN 1643.
A summary of the conditions has been published by the European Control Manufacturers
Association (Afecor) (www.afecor.org).

The designed lifetime is based on use of the LDU11 according to the manufacturer’s
Data Sheet. After reaching the designed lifetime in terms of the number of burner startup
cycles, or the respective time of usage, the LDU11 is to be replaced by authorized
personnel.

* The designed lifetime is not the warranty time specified in the Terms of Delivery

Disposal notes
The unit contains electric and electronic components and must not be disposed of
together with domestic waste. Local and currently valid legislation must be complied with.

Mechanical design

Valve proving system  Plug-in design

LDU11  Exchangeable unit fuse (including spare fuse)

Housing  Made of impact-proof and heat-resistant black plastic

 Lockout reset button with viewing window showing:
– The fault signal lamp
– The lockout indication
- Coupled to the program spindle
- With transparent lockout reset button
- Easy-to-remember symbols indicating the type of fault and the time lockout
occurred
- Synchronous motor of the sequence switch with gear train
- Camshaft with 15 nonadjustable cams
- Program indicator at the head of the camshaft
- 1 main and 1 auxiliary relay
- Lockout relay can be electrically reset from a remote location and provides the
«Lockout» and «Reset» functions
- Unit fuse and spare fuse

All electrical components are interconnected via printed circuits.

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Type summary

Article no. Type Mains voltage t3 t4

BPZ:LDU11.323A17 LDU11.323A17 AC 115 V 2,5 s 2,5 s
BPZ:LDU11.323A27 LDU11.323A27 AC 230 V 2,5 s 2,5 s
BPZ:LDU11.523A17 ¹) LDU11.523A17 ¹) AC 115 V 5s 5s
BPZ:LDU11.523A27 ¹) LDU11.523A27 ¹) AC 230 V 5s 5s

Legend t3 Filling the test space

t4 Evacuating the test space

¹) Valve opening times do not conform to EN 1643

Accessories (to be ordered separately)

Article no. Type

Connection Accessories for Medium-Capacity

Plug-in base with Pg11 threads for cable entry glands.

BPZ:AGM11 AGM11
Refer to Data Sheet N7230.

Plug-in base with M16 threads for cable entry glands.

BPZ:AGM11.1 AGM11.1
Refer to Data Sheet N7230.

Others
PTC resistor (AC 230 V).
BPZ:AGK25 AGK25
For load on terminal 4 of LMG2.

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Technical data

General unit data Mains voltage

LDU11 - LDU11.323A27 AC 230 V –15%/+10%
- LDU11.323A17 AC 115 V –15%/+10%
- LDU11.523A27 ¹) AC 230 V –15%/+10%
- LDU11.523A17 ¹) AC 115 V –15%/+10%
¹) Valve opening times do not conform to EN 1643
Mains frequency 50...60 Hz ±6 %
Unit fuse (built-in) T6.3H250V to DIN EN 60127
Primary fuse (external) Max. 10 A (slow)
Weight Approx. 1000 g
Power consumption
- During the test Approx. AC 3.5 VA
- During operation Approx. AC 2.5 VA
Mounting position Optional
Degree of protection IP40 (to be ensured through mounting),
except the connection area (terminal base)
Safety class II
Perm. input current at terminal 1 Max. 5 A (peak current 20 A / 20 ms)
Perm. current rating of control terminals Max. 4 A (peak current 20 A / 20 ms)
Required current rating of pressure switch Min. 1 A, AC 250 V

Environmental Storage DIN EN 60721-3-1

conditions Climatic conditions Class 1K3
Mechanical conditions Class 1M2
Temperature range -20...+60 °C
Humidity <95 % r.h.
Transport DIN EN 60721-3-2
Climatic conditions Class 2K2
Mechanical conditions Class 2M2
Temperature range -50...+60 °C
Humidity <95 % r.h.
Operation DIN EN 60721-3-3
Climatic conditions Class 3K5
Mechanical conditions Class 3M2
Temperature range -20...+60 °C
Humidity <95 % r.h.
Installation altitude Max. 2,000 m above sea level

Caution!
Condensation, formation of ice and ingress of water are not permitted!
If this is not observed, there is a risk of loss of safety functions and a risk of
electric shock.

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Function
During the first phase of the valve proving test called «Test1», atmospheric pressure
must exist in the length of pipe between the valves to be tested. In plants with a vent pipe
to atmosphere, atmospheric pressure is available if the valve proving test is made prior to
or during the prepurge time. In plants without vent pipe, atmospheric pressure is made
available as the valve proving system opens the valve on the burner side during
evacuating the test space (t4). If the valve proving test LDU11 is performed after burner
operation, the valve on the burner side after the controlled shutdown can be kept open
until evacuating the test space (t4) has elapsed, thus lowering the pressure in the test
space and making certain its gas content is burnt off in the combustion chamber during
the postpurge time. Prerequisite for this procedure is a suitable control program of the
burner control as provided by burner controls type LFE, LFL, LGK or LEC.

The test space is closed off after evacuation. During the first test phase «Test1», which
then follows, the LDU11 checks with the pressure switch if the atmospheric pressure in
the test space is maintained. If the valve on the mains side is leaking, causing the
pressure to rise above the switching point of the pressure switch, the LDU11 will trigger
an alarm and initiate lockout. The program indicator then stops to indicate «Test1».

If the pressure does not increase because the valve closes correctly, the LDU11
continues its program with the second test phase «Test2».
To this end, the valve on the mains side is opened to maintain the gas pressure while the
test space (t3) is being filled.
During the second test phase – if the valve on the burner side is leaking – this pressure
must not fall below the switching point of the pressure switch. If it does, the LDU11 will
initiate lockout also, thus preventing the burner from starting up.

On successful completion of the second test phase, the LDU11 closes the internal control
loop between terminals 3 and 6 (circuit path: terminal 3 - contact (ar2) - terminals 4 and 5
- contact III - terminal 6). This control loop is normally included in the burner control’s
start control loop.

After the control loop has been closed, the programming mechanism of the LDU11
returns to its start position to switch itself off. During these so-called idle steps, the
positions of the programming mechanism’s control contacts remain unchanged.

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Program and lockout indicator
In the event of lockout, the programming mechanism stops and thus the position indicator
fitted to the spindle of the mechanism. The symbol that stops above the reading mark
indicates the test phase during which lockout occurred and also gives the number of
programming steps completed from the start of this test phase (1 step = 2.5 seconds).

Meaning of the ► Start position = operating position

symbols:
In plants without vent valve:
Evacuation of test space by opening the valve on the burner side

Test1 «Test1» with atmospheric pressure (valve proving test on the mains side)

Filling the test space by opening the valve on the mains side

Test2 «Test2» with gas pressure (valve proving test on the burner side)

III 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 valve proving system
LDU11 will be deenergized, except terminal 13, which is used for lockout indication.

After a reset, the programming mechanism automatically returns to its start position to
immediately program a new valve proving test.

 Note!
Do not press the reset button for more than 10 seconds.

Control sequence after A power failure prior to evacuating the test space does not cause the control sequence to
a power failure change.

If a power failure occurs after the evacuation, the valve proving test will not be continued
when power is restored, but the programming mechanism first returns to its start position
and then performs the complete valve proving test.

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Calculation of the leakage rate escaping from a length of pipe

(PG - PW) x V x 3600

QLeck = ----------------------------
Patm x tTest

Legend Qleck in dm³/h Permissible leakage rate in dm³ per hour or liters per hour
PG in kPa Overpressure in pipe section between the valves to be tested, at
the beginning of the test phase
PW in kPa Overpressure set on pressure switch (normally set to 50 % of
the gas mains pressure)
Patm in kPa Absolute pressure (101,3 kPa normal pressure)
V in dm³ Volume of test space confined by the valves to be tested,
including the space in the valves themselves
Ttest in s Duration of proving time

Example (3 - 1.5) x 10.36 x 3600

PG = 3 kPa
QLeck = -------------------------------- = 20 l/h
PW = 1.5 kPa
101.3 x 27.5
Patm = 101.3 kPa
Any valve leakage rate exceeding 20 l/h causes the LDU11 to
initiate lockout
V = 10.36 dm³

tTest = 27.5 s

Note!

 Select volume of pipe section (V) between the gas valves to be checked and
overpressure (PW) set on pressure switch (DW) such that the maximum permissible
gas leakage rate (QLeck) will not exceed the rate specified in the local regulations.

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Connection diagram

L Si

1)
EK2 SK
7696a15/0204
18 1 3 4 5 6 8 10 12 19 23 20 22 21 24
a b a b a b a b
AS ar2 III I V XI hr1
hr2 HR

br1
XIII
IX
ar1 a b a b
15 14

IV Atm. P GP VII
Gas

DW

16 17
VI VIII
b a b a
AR a b
ar3
1) L1
EK1 br2 M
~
SM
BR

13 2 7 9 11
LDU11
AL
N

Legend

AL Alarm signal for «leaking valve»

AR Working relay with contacts (ar...)
AS Unit fuse (built-in)
BR Lockout relay with contacts (br...)
DW Pressure switch for valve proving test (does not replace the gas pressure switch used to signal lack of gas)
EK1 Lockout reset button
EK2 Remote lockout reset button
GP Gas pressure switch (for lack of gas)
HR Auxiliary relay with contacts (hr...)
L1 Lockout warning lamp (built-in)
Si External primary fuse
SK Control contact (for initiating the valve proving test)
SM Synchronous motor of programming mechanism

1) Do not press lockout reset button (EK) for more than 10 seconds

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Sequence diagram

A t5
B C
a
I b 7 8
t20
III 5 6

IV
t4 t1
9
a
V b
9 10
a
VI b

VII

a
VIII b
t6
a
IX b
t3 t2 11 15
a
XI b
11 12

XIII a
b

AR

Output terminals
Test1 Test2 controlled by the
control unit or
electrically
Program indication 7696b01e/0601 connected

Legend

t1 22.5 s *) First test phase with atmospheric pressure

t2 27.5 s *) Second test phase with gas pressure
For LDU11.323...
t3 2.5 s *) Filling the test space
t4 2.5 s *) Evacuating the test space
For LDU11.523...
t3 5 s *) Filling the test space
t4 5 s *) Evacuating the test space
t5 66.3 s *) Total duration of valve proving test until burner is released
t6 7.4 s *) Interval from start to energizing working relay (AR)
t20 22.1 s *) Running time of programming mechanism until it switches itself off in the operating = start position (idle steps)
*) At 50 Hz

A Gas valves controlled to evacuate the test space

B Gas valves controlled to fill the test space
C Vent valve, normally open; closed during valve proving test from the beginning of «Test1»

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Connection examples with vent pipe to atmosphere using burner controls type LGB2 / LGB3 / LGB4 / LMG2
For other connections, refer to the connection diagram of the relevant burner control.

Valve proving test prior to burner startup Valve proving test following immediately the controlled
shutdown
7696a05/0403 7696a06/0703
LGB2.../3.../4.../LMG2... LGB2.../3.../4.../LMG2... 12 3 5 4
12 3 4 5 10
SB / R / W
M 3)
H A2 A1 AGK25
H M A1 A2 L
L
N P GP
N

SB / R / W DW

1 3 6 12 14 19 20 22 21 24 14 15 16 17 3 1 6 8 12 19 23 20 22 21 24
hr2 hr2
ar2 III XI ar2
17 15 hr1 N III I XI hr1 N
2 4 5 16 11 23 LDU11 13 2 4 5 7 11 13
LDU11
GP
DW
C E B AL
C B E AL

³) Only in connection with LMG2

Plants with vent pipe to atmosphere

LDU LDU

GP DW GP DW
A1 A2
E B A E B

C C

7696s01/0695

Connection examples with vent pipe to atmosphere using burner controls type LFE, LFL or LGK, or the control
unit LEC
Check during the prepurge time (min. 60 seconds) and Check following immediately the controlled shutdown
following immediately the controlled shutdown in plants
2)
with vent pipe to atmosphere. Delay on make of relay Expanding flame burner or interrupted pilot burner
d >2 seconds.
2)
Expanding flame burner or interrupted pilot burner
7696a10/0401 7696a11/0401
LFE1 LFE1
8 9 18 19 4 5°/10°° 2) LEC1 8 9 5°/10°° 2)
LEC1
LFL1...
LFL1... 4 5 18°/17°° 2)
LGK16... 4 5 12 13 14 18°/17°° 2) LGK16...

W A
A
R LP W N
N
R
EK2
d 18 1 3 4 5 6 8 10 12 19 23 20 22 21 24
DW
16 hr2
ar2 III
17 I V XI hr1 N
2
15 14 2 7 9 11 LDU11 13
EK2
DW 18 1 34 5 6 8 10 12 19 23 20 22 21 24
16 GP AL
hr2 C E B
ar2 III
I V XI hr1 N N
17
15 14 2 7 9 11 LDU11 13

GP C E B AL
N

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

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

Check just prior to burner startup Check during the prepurge time (min. 60 seconds)
2) 2)
Expanding flame burner or interrupted pilot burner Expanding flame burner or interrupted pilot burner

7696a07/0401 7696a08/0401
LFE1 LFE1
LEC1 8 9 5°/10°° 2) LEC1 8 9 18 19 4 5°/10°° 2)

LFL1... LFL1...
LGK16... 4 5 18°/17°° 2) LGK16... 4 5 12 13 14 18°/17°° 2)

A A
W W

R N N
R LP

EK2 EK2
18 1 3 4 5 6 8 10 12 19 23 20 22 21 24 18 1 3 4 5 6 8 10 12 19 23 20 22 21 24
DW DW
16 hr2 16 hr2
ar2 III ar2 III
17 I V XI 17 I V XI hr1
hr1 N N
15 14 2 7 9 11 LDU11 13 15 14 2 7 9 11 LDU11 13

GP E C B AL GP E C B AL

N N

Valve proving test with 2 pressure switches

DWG Pressure switch for the valve proving test with gas pressure.
This pressure switch must be set to the minimum gas pressure permitted during the proving test.
If this pressure is not reached during the test, lockout will be initiated.

DWA Pressure switch for the gas valve proving test with atmospheric pressure.
This pressure switch must be set to the maximum gas pressure permitted during the proving test with
atmospheric pressure.
If this pressure is exceeded during the test, lockout will be initiated.

Pressure switch (DWG) and pressure switch (DWA) must be overload-proof up to the gas pressure value.

DWG

Plants with vent pipe (C) to atmosphere

SKP7...
LDU LDU

DW DW
B A2
B A

C C

7696s02/0709

LDU LDU

DW DW
B A C

C
B ) ( RB A

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Connection examples without vent pipe to atmosphere (for applications not covered by EN 676) using burner
controls type LFE, LFL or LGK, or the control unit LEC
Check following immediately the controlled shutdown in plants without vent pipe. Valve (A) or valve (A1) remains open
after the controlled shutdown until the start of the first test phase is reached in order to evacuate the test space and to
burn off the gas in the combustion chamber during the afterburn time.
2)
Expanding flame burner or interrupted pilot burner
7696a12/0401
LFE1
LEC1 8 9 5°/10°° 2) 17 3

LFL1...
LGK16... 4 5 18°/17°° 2) 7 6

W
M2
R N

EK2

DW 18 1 3 4 5 6 8 10 12 19 23 20 22 21 24
16 hr2
ar2 III I V XI
17 hr1 N
15 14 2 7 9 11 LDU11 13

GP E A B AL

Valve proving test with 2 pressure switches

DWG Pressure switch for the valve proving test with gas pressure. This pressure switch must be set to the
minimum gas pressure permitted during the proving test. If this pressure is not reached during the test,
lockout will be initiated.

DWA Pressure switch for the gas valve proving test with atmospheric pressure. This pressure switch must be set
to the maximum gas pressure permitted during the proving test with atmospheric pressure. If this pressure
is exceeded during the test, lockout will be initiated.

Pressure switch (DWG) and pressure switch (DWA) must be overload-proof up to the gas pressure value.

DWG

Plants without vent pipe to atmosphere

PL
LDU SKP7... LDU

GP DW GP DW
A1 A2

LDU LDU

GP DW GP DW

) ( RB

Air pressure (PL) for the SKP7 must be sufficiently high to open the SKP7 although the burner’s air damper is closed.
Otherwise, the LDU11 will initiate lockout when performing «Test1».

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Connection examples without vent pipe to atmosphere using burner controls type LGB2 / LGB3 / LGB4 / LMG2

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

Check prior to burner startup Check following immediately the controlled shutdown

7696a13/0403 7696a14/0703
LGB2.../3.../4.../LMG2... 12 3 4 5 10 LGB2.../3.../4.../LMG2... 12 3 5 4

SB / R / W
L
H M A2 M A2 AGK25 3)
N GP P N N N

SB / R / W H
L

1 3 4 5 6 10 12 14 19 20 22 21 24 1 3 4 5 6 8 10 12 19 23 20 22 21 24
DW DW
hr2 16 hr2
16 ar2 III
ar2 III XI I V XI
17 V 17 hr1 N
hr1 N
11 23 13 15 14 2 7 9 11 13
15 2 9 LDU11 LDU11

GP

E A1 B AL
A1 B E AL
N
N

³) Only in connection with LMG2

Plants without vent pipe to atmosphere

LDU LDU
7696s04/0695
GP DW GP DW
A1 A2
E B A E B

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Connection examples without vent pipe to atmosphere using burner controls type LFE, LFL or LGK, or the
control unit LEC
For other connections, refer to the connection diagram of the relevant burner control.

Check just prior to burner startup Check during the prepurge time (min. 60 seconds)
2) 2)
Expanding flame burner or interrupted pilot burner Expanding flame burner or interrupted pilot burner

7696a24/0401 7696a25/0401
LFE1 LFE1
LEC1 8 9 5°/10°° 2) LEC1 8 9 18 19 4 5°/10°° 2)

LFL1... LFL1...
LGK16... 4 5 18°/17°° 2) LGK16... 4 5 12 13 14 18°/17°°2)

W W

R LP
R

EK2 EK2

DW 18 1 34 5 6 8 10 12 19 23 20 22 21 24 18 1 3 4 5 6 8 10 12 19 23 20 22 21 24
DW
16 hr2 16 hr2
ar2 III ar2 III
17 I V XI hr1 17 I V XI
N hr1 N
15 14 2 7 9 11 LDU11 13 15 14 2 7 9 11 LDU11 13

GP E A B AL GP E A B AL

N N

Valve proving test with 2 pressure switches

DWG Pressure switch for the valve proving test with gas pressure. This pressure switch must be set to the
minimum gas pressure permitted during the proving test. If this pressure is not reached during the test,
lockout will be initiated.

DWA Pressure switch for the gas valve proving test with atmospheric pressure. This pressure switch must be set
to the maximum gas pressure permitted during the proving test with atmospheric pressure. If this pressure
is exceeded during the test, lockout will be initiated.

Pressure switch (DWG) and pressure switch (DWA) must be overload-proof up to the gas pressure value.

DWG

Plants without vent pipe to atmosphere

SKP7...

Air pressure (PL) for the SKP7 must be sufficiently high to open the SKP7 although the burner’s air damper is closed.
Otherwise, the LDU11 will initiate lockout when performing «Test1».

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Connection examples without vent pipe to atmosphere using burner controls type LFE, LFL or LGK, or control
unit LEC and actuator SKP7 with expanding flame burners

For other connections, refer to the connection diagram of the relevant burner control

Check just prior to burner startup Check during the prepurge time (min. 60 seconds)

7696a26/0401 7696a27/0401
LFE1 LFE1
LEC1 8 9 18 19 4 5° 3/17 8 9 18 19 4 3/17
LEC1 5°
LFL1...
LGK16... 4 5 12 13 14 18° 6/7 LFL1...
LGK16... 4 5 12 13 14 18° 6/7

T
W
N M W
R LP LP
R N
EK2 M
8 EK2
DW 18 3 4 5 6 10 12 19 23 20 22 21 24
16 1 hr2 DW 18 1 3 4 5 6 8 10 12 19 23 20 22 21 24
ar2

17 III I V XI 16 hr2
hr1 N III
17 ar2 I V XI
15 14 2 7 9 11 13 hr1 N
LDU11
15 14 2 7 9 11 LDU11 13

GP E A B AL

N GP E A B AL

Valve proving test with 2 pressure switches

DWG Pressure switch for the valve proving test with gas pressure. This pressure switch must be set to the
minimum gas pressure permitted during the proving test. If this pressure is not reached during the test,
lockout will be initiated.

DWA Pressure switch for the gas valve proving test with atmospheric pressure. This pressure switch must be set
to the maximum gas pressure permitted during the proving test with atmospheric pressure. If this pressure
is exceeded during the test, lockout will be initiated.

Pressure switch (DWG) and pressure switch (DWA) must be overload-proof up to the gas pressure level.

DWG

Plants without vent pipe to atmosphere

SKP7...

GP DW
E B A

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Connection examples without vent pipe to atmosphere using burner controls type LME21.xxxCx / LME22.xxxCx
with expanding flame burners
For other connections, refer to the connection diagram of the relevant burner control.
 LME21.xxxCx / LME22.xxxCx with LDU11 valve proving
 Before startup of burner
 In the case of plants without vent pipe to atmosphere

LME21.xxxC...
NT LME22.xxxC... RESET

K1
K2/1 K2/2 K3 K4 K5

Gpmin

LP
R/W
1)
T
AL M Z A2 M EK2
STB

1)

7101a28e/0210

I ar2 hr1 hr2 HR III V XI LDU11...

DW
E A1 B
Gas Atmospheric

LDU LDU

GP GP

1) Fan motor connected to terminal 3 of the LME21.xxxCx / LME22.xxxCx

 Valve proving is started each time the system is switched on, with connection of
terminal 3, after controller ON or after lockout
 If the LDU11 initiates lockout, valve proving can take up to 160 seconds. Therefore,
the maximum permissible response time of the air pressure switch is 180 seconds
 With the LDU11…, faults during valve proving lead to lockout and, with the
LME21.xxxCx / LME22.xxxCx , to lockout due to air pressure switch timeout (blink
code 03)

 Note!
A faulty air pressure switch (switch does not make) leads to lockout (blink code 03)
on completion of the pressure switch response time of 180 seconds and can be
distinguished from lockout due to faulty valve proving only because the LDU11 did
not go to lockout
 The fan motor can be connected either to terminal 3 in connection with a link
between terminals 6 and 24 of the LDU11 (motor active during valve proving) or to
terminal 6 of the LDU11 (motor active on completion of successful valve proving)

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Connection examples with vent pipe to atmosphere using burner controls type LME21.xxxCx / LME22.xxxCx
with expanding flame burners
For other connections, refer to the connection diagram of the relevant burner control.
 LME21.xxxCx / LME22.xxxCx with LDU11 valve proving
 Valve supervision before startup of burner
 In the case of plants with vent pipe to atmosphere

LME21.xxxC...
NT LME22.xxxC... RESET

K1
K2/1 K2/2 K3 K4 K5

Gpmin

LP
R/W
1)
T
AL M Z A1 A2 M EK2
STB

1)

7101a29e/0210

I ar2 hr1 hr2 HR III V XI LDU11...

DW
E C B
Gas Atmospheric

GP GP

1) Fan motor connected to terminal 3 of the LME21.xxxCx / LME22.xxxCx

 Valve proving is started each time the system is switched on, with connection of
terminal 3, after controller ON or after lockout
 If the LDU11 initiates lockout, valve proving can take up to 160 seconds. Therefore,
the maximum permissible response time of the air pressure switch is 180 seconds
 With the LDU11…, faults during valve proving lead to lockout and, with the
LME21.xxxCx / LME22.xxxCx , to lockout due to air pressure switch timeout (blink
code 03)

 Note!
A faulty air pressure switch (switch does not make) leads to lockout (blink code 03)
on completion of the pressure switch response time of 180 seconds and can be
distinguished from lockout due to faulty valve proving only because the LDU11 did
not go to lockout
 The fan motor can be connected either to terminal 3 in connection with a link between
terminals 6 and 24 of the LDU11 (motor active during valve proving) or to terminal 6
of the LDU11 (motor active on completion of successful valve proving)

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Legend

A, A1, A2 Gas valves controlled to evacuate the test space

AGK25 PTC resistor
AL Alarm signal for «leaking valve»
ar... Contacts (operating relay)
B Gas valve controlled to fill the test space
C Vent valve, normally open; closed during valve proving test from the
beginning of «Test1»
DW Pressure switch for valve proving test (does not replace the gas pressure
switch used to signal lack of gas)
E Safety shutoff valve, dead closed (optional)
EK Lockout reset button (internal)
EK2 Remote lockout reset button
FSV Flame signal amplifier
GP Gas pressure switch (for lack of gas)
H Main switch
ION Ionization probe
K1...4 Internal relays
hr... Contacts (auxiliary relay)
LP Air pressure switch
M... Fan («M2»: pre- and postpurging)
NT Power supply
PL Combustion chamber pressure (reference variable) for SKP7
R Control thermostat or pressurestat (e.g. boiler control thermostat)
RB Pipe orifice; its diameter must be determined such that in the event of a
leaking ignition gas valve (A), the ignition flame cannot afterburn on
completion of the second safety time so that presence of the main flame
cannot be simulated
SB Safety limit thermostat
STB Safety limit thermostat
T Delay off time relay; the time should be set to approx. «t16» (min. «t7»...
max. «t10») of the burner control
W Limit thermostat or pressure switch or pressure limiter
Z Ignition transformer

t7 Interval between start command and power at terminal 7 (start delay for
«M2»)
t10 Interval from start to the beginning of the air pressure check, excluding
running time of air damper
t16 Interval until OPEN command for the air damper is given

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 Dimensions

Dimensions in mm

LDU11

1,5
108,5

123
Plug-in base AGM11 / AGM11.1

7696m04/0305

27,5 27,5

37

103
7,5

103

2018 Siemens AG Building Technologies, Berliner Ring 23, D-76437 Rastatt

Subject to change!
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