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Adjusting minimum pressure setting (see fig. 3.)
Connect a suitable pressure gauge to pipe line or to outlet
pressure tap of gas control concerned, to measure burner
pressure (measuring point must be as near to burner as
possible).
Disconnect electrical connection of Modureg.
Energize operator, set control in operation and wait until an
outlet pressure is recorded on pressure gauge.
If minimum rate pressure needs adjustment then use
a 9 mm wrench to turn adjustment screw for minimum
pressure setting clockwise to increase or
counter--clockwise to decrease pressure, until the desired
minimum outlet pressure is obtained.
Check if main burner lights easily and reliable at minimum
pressure.
Check maximum pressure setting and readjust if
necessary.
Mount cap.
Adjusting maximum pressure setting (see fig. 3.)
Connect a suitable pressure gauge to pipe line or to outlet
pressure tap of gas control concerned, to measure burner
pressure (measuring point must be as near to burner as
possible).
Disconnect electrical connection of Modureg.
Energize operator, set control in operation and wait until an
outlet pressure is recorded on pressure gauge.
Push shaft gently downwards to the maximum adjustment
screw and hold it on.
If maximum rate pressure needs adjustment then use
a 7 mm wrench to turn adjustment screw for maximum
pressure setting clockwise to increase or
counter--clockwise to decrease pressure, until the desired
maximum outlet pressure is obtained.
Release shaft.
Mount cap.
If minimum and maximum pressures are set, wire Modureg in
circuit.
Adjusting intermediate pressure setting
Some controls, such as W9335, are able to provide
modulating control as well as a fixed setting.
In case this intermediate pressure setting should be set, it is
necessary to follow the suppliers instructions regarding the
adjustment of the concerned control. It deals with the
switching from modulating mode to fixed setting mode which
is in most cases is a potentiometer.
The fixed setting mode is very often used for central heating,
where on/off adjustable pressure to burner is required.
This intermediate outlet pressure can in general be electrically
set as follows:
Connect a suitable pressure gauge to pipe line or to outlet
pressure tap of gas control concerned, to measure burner
pressure (measuring point must be as near to burner as
possible).
Energize operator, set control in operation and wait until an
outlet pressure is recorded on pressure gauge.
Make sure Modureg is wired in the circuit.
Bring system in fixed setting mode.
Adjust current as low as needed to obtain the lowest
pressure by using pressure setting means of control.
Mechanical setting of Modureg will prevent too low setting.
Increase the current until desired pressure is obtained by
using pressure setting means of modulating control.
Mount cap.
Checkout
After any adjustment, set appliance in operation and observe
through a complete cycle to ensure that burner system
components function correctly.
Maintenance
It is recommendable to check yearly the minimum and the
maximum setting and readjust them if necessary.
Dismounting and remounting flanges
Though by careful handling the "O"--rings could be re--used
when they are undamaged, it is advisable to use new
"O"--rings to be sure to have a reliable tight connection.
SPECIFICATIONS VR4920P
Model
VR4920P: line voltage gas control, fast opening with
High--Low regulator.
Ambient temperature
0 ... 70 _C
Minimum operating pressure
Between inlet and outlet: 3 mbar
Adjustment points and dimensions
See fig. 4. page 6
Maximum operating pressure
The P
indication 30 mbar on the housing of the
max.
combination gas control is the maximum pressure at which
the gas control functions safely. However the maximum
operating pressure is limited by the pressure range of the
High--Low pressure regulator concerned.
30 mbar for pressure range 3 ... 20 mbar
Regulator outlet pressure range V4336A
Pressure range
Low setting
(mbar)
(mbar)
3 ... 20
3 ... max. setting
The outlet pressure setting should never be above the
range specified.
Electrical data gas control
Nominal voltage
15 Vdc
240/240 Vac, 50 Hz
Electrical data High- Low regulator V4336
Supply
Color of
voltage
coil
(Vac)
220/240 V,
black
50 Hz
The High/Low regulator should never be covered in such
a way that temperature will raise beyond acceptable
limits.
Electrical connection
The electric servo on/off operators are provided with: 6.3 mm
quick connect terminals suitable for 6.3 mm receptacles. (e.g.
"Series 250" AMP fasteners)
5
High setting
(mbar)
7 ... 20
Current (mA)
Power
consumption
(W)
313
4.7
20.4/24
3.4/4.5
Current
Power
(mA)
consumption
(W)
17.4/19
3/3.2
EN1R- -9181 0104R1- -NE
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