Kromschroeder VAD User manual

CONTENTS
Cert. Version 07.19 · Edition 03.23 · EN · 03250481
DE, EN, FR, NL, IT, ES, DA, SV, NO, PT, EL, TR, CS, PL, RU, HU – www.docuthek.com
Pressure regulators with solenoid valve VAD, VAG, VAV,
VAH, flow rate regulators VRH, pressure regulators with
double solenoid valve VCD, VCG, VCV, VCH
1 Safety ................................1
2 Checking the usage .....................2
3 Installation ............................3
4 Installing the gas/air control lines ...........5
5 Wiring................................ 7
6 Tightness test..........................8
7 Commissioning.........................9
8 Replacing the actuator ..................11
9 Replacing the circuit board...............12
10 Maintenance.........................13
11 Accessories .........................13
12 Technical data .......................17
13 Air flow rate Q........................19
14 Designed lifetime .....................19
15 Certification .........................20
16 Logistics ............................21
17 Disposal ............................21
1 SAFETY
1.1 Please read and keep in a safe place
Please read through these instructions
carefully before installing or operating. Following the
installation, pass the instructions on to the operator.
This unit must be installed and commissioned in
accordance with the regulations and standards in
force. These instructions can also be found at www.
docuthek.com.
1.2 Explanation of symbols
1, 2, 3, a, b, c = Action
➔= Instruction
1.3 Liability
We will not be held liable for damage resulting from
non-observance of the instructions and non-com-
pliant use.
1.4 Safety instructions
Information that is relevant for safety is indicated in
the instructions as follows:
DANGER
Indicates potentially fatal situations.
WARNING
Indicates possible danger to life and limb.
CAUTION
Indicates possible material damage.
All interventions may only be carried out by qualified
gas technicians. Electrical interventions may only be
carried out by qualified electricians.
1.5 Conversion, spare parts
All technical changes are prohibited. Only use OEM
spare parts.
OPERATING INSTRUCTIONS

VAx · Edition 03.23
EN-2
2 CHECKING THE USAGE
Pressure regulators with solenoid valve VAD,
VAG, VAV, VAH
Type Designation of regulator type
VAD Pressure regulator with solenoid valve
VAG Air/gas ratio control with solenoid valve
VAV Variable air/gas ratio control with solenoid
valve
VAH Flow rate regulator with solenoid valve
Constant pressure governor VAD for shut-off and
precise control of the gas supply to excess air
burners, atmospheric burners or force draught gas
burners.
Air/gas ratio control VAG for shut-off and for main-
taining a constant air/gas pressure ratio of 1:1 for
modulating-controlled burners or with bypass valve
for stage-controlled burners. Can be used as zero
governor for gas engines.
Variable air/gas ratio control VAV for shut-off and
for maintaining a constant air/gas pressure ratio for
modulating-controlled burners. The transmission
ratio of gas to air can be set from 0.6:1 to 3:1. Pres-
sure fluctuations in the combustion chamber can be
compensated via the combustion chamber control
pressure psc.
Flow rate regulator VAH for maintaining a con-
stant gas/air ratio for modulating-controlled and
stage-controlled burners. The gas flow rate is con-
trolled proportionally to the air flow rate. In addition,
the flow rate regulator with gas solenoid valve shuts
off the gas or air supply safely.
Flow rate regulator VRH
Type Designation of regulator type
VRH Flow rate regulator
Flow rate regulator VRH for maintaining a con-
stant gas/air ratio for modulating-controlled and
stage-controlled burners. The gas flow rate is
controlled proportionally to the air flow rate.
Pressure regulators with double solenoid valve
VCD, VCG, VCV, VCH
Type
Combination of
gas solenoid valve +
regulator with solenoid valve
VCD VAS + VAD
VCG VAS + VAD
VCV VAS + VAV
VCH VAS + VAH
Gas solenoid valves VAS for safeguarding gas or
air on various appliances. Pressure regulators with
double solenoid valveVCx are combinations of two
gas solenoid valves with a pressure regulator.
This function is only guaranteed when used within
the specified limits– see page 17 (12 Technical
data). Any other use is considered as non-compliant.
2.1 Type code
VAD Pressure regulator with solenoid valve
VAG Air/gas ratio control with solenoid valve
VAH Flow rate regulator with solenoid valve
VAV Variable air/gas ratio control with sole-
noid valve
VRH Flow rate regulator
1-3 Sizes
15–50 Inlet and outlet flange nominal size
RRp internal thread
FFlange to ISO 7005
/N Quick opening, quick closing
WMains voltage 230V AC, 50/60Hz
YMains voltage 200V AC, 50/60Hz
QMains voltage 120V AC, 50/60Hz
PMains voltage 100V AC, 50/60Hz
KMains voltage 24V DC
SR Closed position switch with visual posi-
tion indicator, right
SL Closed position switch with visual posi-
tion indicator, left
GR Closed position switch for 24V and
visual position indicator, right
GL Closed position switch for 24V and
visual position indicator, left
-25 Outlet pressure pdfor VAD: 2.5–25mbar
-50 Outlet pressure pdfor VAD: 20–50mbar
-100 Outlet pressure pdfor VAD:
35–100mbar
AStandard valve seat
BReduced valve seat
EVAG, VAV, VAH, VRH: connection for air
control pressure: compression fitting
KVAG, VAV: connection for air control
pressure: plastic hose coupling
AVAG, VAV, VAH, VRH: connection for air
control pressure: 1/8" NPT adapter
NVAG: zero governor
VRH: no solenoid valve
2.2 Part designations
VAx..S,
VAx..G
VAD, VAG,
VAV, VAH
VRH
2
3
4
8
6
7
5
1
1 Solenoid actuator
2 Flow body
3 Connection box
4 Connection flange
5 Closed position indicator CPI
6 Connection parts
7 Regulator

VAx · Edition 03.23
EN-3
2.3 Type label
Mains voltage, electrical power consumption,
ambient temperature, enclosure, inlet pressure and
installation position: see type label.
Elster GmbH
Osnabrück, Germany
Vxx
.XXXX
3 INSTALLATION
CAUTION
Incorrect installation
Please observe the following to ensure that the
unit is not damaged during installation and oper-
ation:
– Sealing material and dirt, e.g. thread cuttings,
must not be allowed to get into the valve
housing.
– A filter must be installed upstream of every
system.
– Always install an activated carbon filter
upstream of the regulator when air is the
medium. Otherwise, the ageing of elastomer
materials will be accelerated.
– Dropping the device can cause permanent
damage. In this event, replace the entire device
and associated modules before use.
– Do not clamp the unit in a vice. Only secure the
flange by holding the octagon with a suitable
spanner. Risk of external leakage.
– It is not permitted to install gas solenoid
valveVAS downstream of flow rate regula-
torVAH/VRH and upstream of fine-adjusting
valveVMV. The VAS would no longer be able to
perform its function as a second safety valve if
installed in the above-mentioned position.
– If more than three valVario controls are installed
in line, the controls must be supported.
– Device with POC/CPI VAx..SR/SL: actuator
cannot be rotated.
– In the case of double solenoid valves, the
position of the connection box can only be
changed by removing the actuator and
reinstalling it rotated by 90° or180°.
When using a non-return gas valveGRS, we
recommend installing the non-return gas valve
upstream of the regulator and downstream of the
gas solenoid valves due to the permanent pressure
loss on theGRS.
➔When joining two valves, determine the position
of the connection boxes, push through the
knock-outs in the connection boxes and install
a cable gland set before installation in the
pipework, see accessories, cable gland set for
double solenoid valves.
➔Install the unit in the pipe free of mechanical
stress.
➔For retrofitting a second gas solenoid valve, use
the double block seal instead of O-rings. The
double block seal is supplied with the seal set,
see accessories, seal set for sizes1–3.
Installation position
VAD, VAG,
VAH, VRH
VAD, VAG,
VAV, VAH,
VRH
VAD, VAG, VAH: black solenoid actuator in the
vertical upright position or tilted up to the horizontal,
not upside down. In humid environments: black
solenoid actuator in the vertical upright position only.
VAG/VAH/VRH: in the horizontal position with mod-
ulating control: min. inlet pressure pu min.= 80mbar
(32"WC).
VAV: black solenoid actuator in the vertical position,
not upside down.
➔The housing must not be in contact with mason-
ry, minimum clearance 20mm (0.79").
➔Ensure that there is sufficient space for in-
stallation, adjustment and maintenance work.
Minimum clearance of 50cm (19.7") above the
black solenoid actuator.
➔To prevent vibrations, keep the volume between
the regulator and burner small by using short
pipes (≤ 0,5m, ≤ 19,7").
The inlet pressure pucan be measured on both
sides of the valve body.
p
upd
pd
The outlet pressure pd(pdand pd-) and the air
control pressure psa (psa and psa-) must only be
measured at the designated places on the regulator
using test nipples.

VAx · Edition 03.23
EN-4
VAD
pd
(psa
)
Test point for the gas outlet pressurepdon the regu-
lator body. A combustion chamber control line (psc)
can be connected at connectionpsa for maintaining
a constant burner capacity (1/8" coupling with
compression fitting for 6x1 tube).
VAG
p
sa
pd
p
sa
VAV
pd
p
sa
p
sc
VAH, VRH
psa
p
sa-
psa
pd
pd-
pd-
psa-
To increase the control accuracy, an external
impulse line can be connected, instead of pressure
test pointpd: Gas impulse line pd: distance from
flange ≥3xDN, use a 8x1mm steel tube and a
G1/8.. coupling for D= 8mm.
CAUTION
Do not bridge downstream VAS with external
impulse line.
Strainer
➔A strainer must be fitted in the unit on the inlet
side. If two or more gas solenoid valves are
installed in line, then a strainer only needs to be
fitted on the inlet side of the first valve.
Differential pressure orifice
➔An appropriate differential pressure orifice with
rubber seals Gmust be inserted at the outlet of
the unit, depending on the pipe.
G
Pipe
DN Differential pressure orifice
Colour Outlet dia. Order
No.
mm inch
VAx
115 Yellow 18.5 0.67
74922238
VAx
120 Green 25 0.98
74922239
VAx
125 Trans- parent 30 1.18
74922240
VAx
240 Trans- parent 46 1.81
74924907
VAx
350 Trans- parent 58 2.28
74924908
If pressure regulator VAD/VAG/VAV1 is retrofitted
upstream of gas solenoid valve VAS1, a DN25
differential pressure orifice with outlet opening
d=30mm(1.18") must be inserted at the outlet of
the pressure regulator.
In the case of pressure regulator VAx115 or
VAx120, the DN25 differential pressure orifice
must be ordered separately and retrofitted, Order
No.74922240.
➔The retaining frame must be fitted to secure the
differential pressure orifice at the outlet of the
regulator.
Retaining frame
➔If two controls (regulators or valves) are assem-
bled, a retaining frame with double block seal
must be fitted.
Order No. for seal set: size 1: 74921988, size 2:
74921989, size 3: 74921990.

VAx · Edition 03.23
EN-5
Compression fittings
➔The seals in some compression fittings are
approved for temperatures of up to 70°C (158°F).
This temperature limit will not be exceeded
if the flow through the pipe is at least 1m3/h
(35.31SCFH) of gas and the maximum ambient
temperature is 50°C (122°F).
1 Remove the adhesive label or screw cap from
the inlet and outlet.
2 Obey the direction of flow as marked on the
housing.
3.1 VAx with flanges
a b c
3.2 VAx without flanges
a b c
➔O-ring and strainer (Fig. c) must be fitted.
d e
➔Note the recommended tightening torques for
the connection parts. See page 18 (12.2.1
Tightening torque).
f g
4 INSTALLING THE GAS/AIR CON-
TROL LINES
CAUTION
Incorrect installation
Please observe the following to ensure that the
unit is not damaged during installation and oper-
ation:
– Fit control lines so that no condensation can
enter the unit.
– The control lines must be as short as possible.
Internal diameter ≥3.9mm(0.15").
– Any bends, restriction points, deviations or air
control valves must be at a distance of at least 5
x DN from the connection.
– Check the connections, pressures, adjusting
range, transmission ratio and pressure
differentials. See page 18 (12.2 Mechanical
data).
VAG
Installing the air control linepsa
1 Install the connection for the air control line in the
centre of a straight pipeline which is at least
10xDN long.
➔VAG..K: 1 x 1/8" coupling for plastic hose
(internal dia. 3.9mm(0.15"), external dia.
6.1mm(0.24")).
➔VAG..E: 1 x 1/8" coupling with compression
fitting for 6 x 1 tube.
➔VAG..N: connection psa must remain open.
5xDN
5xDN
psa

VAx · Edition 03.23
EN-6
VAV
Installing the air control linepsa and the com-
bustion chamber control linepsc
psc
psa
VAS
VAV
DG..C
(DG..VT)
min.
➔VAV..K: 2 plastic hose couplings (internal dia.
3.9mm(0.15"); external dia. 6.1mm(0.24"))
available.
➔Do not remove the couplings or replace them
with other types of coupling.
1 Route air control linepsa and combustion
chamber control linepsc to the test points for air
and combustion chamber pressure.
➔If psc is not connected, do not plug the opening!
2 Install the connection for the air control line in the
centre of a straight pipeline which is at least
10xDN long.
5xDN
5xDN psc
psa
VAH/VRH
Installing the air control lines psa/psa- and the
gas control line pd-
➔3 x 1/8" couplings with compression fitting for
6x1 tube.
1 To measure the differential air pressure, install a
measuring orifice in the air line, ensuring that the
inlet and outlet section is ≥5DN.
2 Connect the air control linepsa to the inlet of the
measuring orifice and the air control linepsa- to
the outlet of the measuring orifice.
➔pdis an internal hole/feedback in the unit.
VAH
VMV
VMO
VAH
psa
pd-
psa-
M
VRH
VMV
VRH
psa psa-
pd-
M
3 We recommend installing a fine-adjusting valve
VMV directly downstream of the regulator in the
gas line. See “Filter module VMF, measuring
orifice VMO, fine-adjusting valve VMV” operating
instructions. The instruction manual can also be
found at www.docuthek.com.
2,5 mm
➔If, instead of installing a VMV, a measuring orifice
is installed in the gas line, ensure that the inlet
and outlet section is ≥5DN.
4 Connect the gas control line pd- to the VMV or to
the measuring orifice.
pd-
5xDN
5xDN
psa-
psa

VAx · Edition 03.23
EN-7
5 WIRING
WARNING
Risk of injury!
Please observe the following to ensure that no
damage occurs:
– Electric shocks can be fatal! Before working on
possible live components, ensure the unit is
disconnected from the power supply.
– The solenoid actuator heats up during
operation. Surface temperature approx. 85°C
(approx. 185°F).
➔Use temperature-resistant cable (>80°C).
1 Disconnect the system from the electrical power
supply.
2 Shut off the gas supply.
➔UL requirements for the NAFTA market. To
maintain the UL environmental rating Type 2, the
enclosure openings shall be closed with fittings
rated UL Type 2; 3; 3R; 3RX; 3S; 3SX; 3X; 4X;
5; 6; 6P; 12; 12K or 13. Gas solenoid valves
shall be protected by a branch circuit protective
device not exceeding 15A.
➔Wiring to EN60204-1.
➔Push through and remove the knock-out in the
connection box before removing the cover. If the
M20 cable gland or plug is already fitted, it is not
necessary to remove the knock-out.
3 4
M20 cable gland
a b c
d e
(+)
LV1 N
(-)
LV1 NLV1 N
(+) (+) (-)(-)
Plug
➔LV1V1 (+) = black, LV1V2 (+) = brown, N (–) = blue
a b
(+)
LV1 N
(-)
LV1 NLV1 N
(+) (+) (-)(-)
Socket
➔1 = N (–), 2 = LV1V1 (+), 3 = LV1V2 (+)
a b c
d e
21
21
3

VAx · Edition 03.23
EN-8
Closed position indicator
➔VAx open: contacts 1and2closed,
VAx closed: contacts 1and 3closed.
➔Indicator of closed position indicator: red = VAx
open, white = VAx closed.
➔Double solenoid valve: if a plug with socket is
fitted, only one closed position indicator can be
connected.
CAUTION
Please observe the following to ensure smooth
operation:
– The closed position indicator is not suitable for
frequent cycling operation.
– Route valve and closed position indicator cables
separately through M20 cable glands or use two
separate plugs. Otherwise, there is a risk of
interference between valve voltage and closed
position indicator voltage.
➔To make wiring easier, the connection terminal for
the proof of closure switch can be removed.
1
2
Valve open
Valve closed
COM 3
1 32
LV1
(+)
N
(-)
1 32 LV1
(+)
N
(-)
1 3
2LV1
(+)
N
(-) 132 LV1 (+)
N
(-)
LV1
(+)
N
(-)
1
2
Valve open
Valve closed
COM 3
1 32
LV1
(+)
N
(-)
➔When installing two plugs on VAx a with proof of
closure switch: label the sockets and plugs to
avoid confusion.
21
3
21
1
COM
2
Valve open
Valve closed
3
➔Ensure that the connection terminal for the
closed position indicator has been reconnected.
Finishing the wiring
5
6 TIGHTNESS TEST
1 Close the gas solenoid valve.
2 To be able to check the tightness, shut off the
downstream pipeline close to the valve.
➔On the VAH/VRH, the control line pd- leads to
gas-filled space in the regulator. It must be con-
nected before the tightness test.
3
0
4
5
0
6 Open the pressure regulator.
7
0
8
9 Tightness OK: open the pipeline.
➔Pipeline leaking: replace the seal on the flange,
see accessories.
Order No. for seal set: size 1: 74921988, size 2:
74921989, size 3: 74921990.
Then check for tightness once again.
➔Unit leaking: remove the unit and return it to the
manufacturer.

VAx · Edition 03.23
EN-9
7 COMMISSIONING
➔Ensure that the length of the tube is as short as
possible for the determining of the pressures
during the measurement process.
VAD
Setting the outlet pressure pd
➔The outlet pressure is set to pd= 10mbar at the
factory.
pd
[mbar] ["WC]
VAD..-25 2.5–25 1–10
VAD..-50 20–50 8–19.7
VAD..-100 35–100 14–40
1 Switch on the burner.
➔Breathing orifice Amust remain open.
2 Set the regulator to the required outlet pressure.
+
_
0
pd
2,5 mm
A
3 Close off the test point again once the pressure
has been set.
VAG
pd= Outlet pressure
psa = Air control pressure
➔Factory setting: pd= psa - 1.5mbar (0.6"WC);
actuator pointing upwards and an inlet pressure
of 20mbar(7.8"WC)
1 Switch on the burner.
Setting the low-fire rate
➔In applications with excess air, the values for
pdand psa may be below the limit, see page
18 (12.2 Mechanical data). No situation which
would jeopardize safety must arise. Avoid CO
formation.
2 Set the regulator to the required outlet pressure.
2,5 mm 0
0
pd
psa
3 Close off the test point again once the pressure
has been set.
Setting the high-fire rate
➔Set the high-fire rate using restricting orifices or
adjustment elements on the burner.
VAV
pd= Outlet pressure
psa = Air control pressure
psc = Combustion chamber control pressure
Setting the low-fire rate
➔If the burner operates at low-fire rate, the gas/
air mixture can be changed by adjusting the
adjusting screw“N”.
-1
0+0,5-0,5
–
+1
-1,5
mbar
+1,5
0,6
1 1,5
2
3
N V
+
+
–
+
_
2,5 mm
CAUTION
psa-psc≥0.4mbar (≥0.15"WC). Controller
acting time for the reference variable (air butterfly
valve): min. to max. >5s, max. to min. >5s.
➔Factory setting for transmission ratio of gas to
air: V=1:1, zero pointN=0.
Presetting
1 Set zero point Nand transmission ratio Vto
scale in accordance with burner manufacturer’s
specifications.
2 Measure gas pressurepd.
0
0
p
d
p
sa
psc
0
3 Start the burner at low-fire rate. If the burner
does not start, turn Nslightly in direction+ and
repeat start.
4 Gradually increase the burner to high fire and, if
necessary, adjust the gas pressure at V.
5 Set the minimum and maximum capacity on the
air control valve in accordance with burner
manufacturer’s specifications.

VAx · Edition 03.23
EN-10
Final adjustment
6 Set the burner to low fire.
7 Conduct a flue gas analysis and set the gas
pressure at Nto the desired analysis value.
8 Set the burner to high fire and set the gas
pressure at Vto the desired analysis value.
9 Repeat the analysis at low and high fire and
correct Nand Vif necessary.
10 Close off all test points. Do not close off
connectionpsc if not used!
➔It is advisable to start the burner at a level higher
than the minimum setting (start gas rate) to
ensure reliable flame formation.
Calculation
If the combustion chamber control pressurepsc is
not connected:
pd= V x psa + N
If combustion chamber control pressurepsc is
connected:
(pd- psc) = V x (psa - psc) + N
Testing control capacity
DANGER
Risk of explosion!
If the control capacity is insufficient, the system
may not be operated.
11 Set the burner to high fire.
12 Measure the gas pressure at the inlet and outlet.
13 Slowly close the manual valve upstream of the
regulator until the gas inlet pressurepudrops.
➔The gas outlet pressurepdshould not drop,
however. Otherwise, the setting should be re-
checked and adjusted.
14 Reopen the manual valve.
VAH, VRH
pu= Inlet pressure
pd= Outlet pressure
Δpd= Differential gas pressure (outlet pressure)
psa = Air control pressure
Δpsa = Differential air pressure (air control pressure)
➔A gas/air mixture may be applied at the psa- con-
nection for the air control pressure.
➔Inlet pressure pu: max. 500mbar
➔Air control pressure psa: 0.6 to 100mbar
➔Differential air pressure Δpsa (psa - psa-)= 0.6to
50mbar
➔Differential gas pressure Δpd(pd- pd-)= 0.6to
50mbar
➔The impulse lines psa, psa- and pd- must be laid
correctly.
VMV
VMO
VAH
psa
pd-
psa-
M
Presetting
1 Set the minimum and maximum capacity on the
air control valve in accordance with burner
manufacturer’s specifications.
2 Switch on the burner.
0
0
pd
psa
pd-
psa-
3 Open the fine-adjusting valve VMV slowly, from
the ignitable mixture with excess air to the
required value.
Setting the high-fire rate
4 Slowly increase the burner to high fire and set
the differential gas pressure on the fine-adjusting
valveVMV in accordance with burner manufac-
turer’s specifications.
Setting the low-fire rate
5 If the burner operates at low-fire rate, the gas/air
mixture can be changed by adjusting the
adjusting screw N.
+3
0-1,5+1,5
–
-3
+5
mbar
-5
N
+
2,5 mm
➔Factory setting: zero point N = -1.5mbar
CAUTION
Δpsa = psa - psa- ≥ 0.6mbar (≥ 0.23 "WC). Con-
troller acting time for the reference variable (air
butterfly valve): min. to max. >5s, max. to min.
>5s.
6 Set the burner to low fire.
7 Conduct a flue gas analysis and set the gas
pressure at Nto the desired analysis value.
8 Set the burner to high fire and set the differential
gas pressure to the desired analysis value.
9 Repeat the analysis at low and high fire and
correct if necessary.
10 Close off all test points.