26
Adjusting maximum pressure setting
•
Disconnect pressure feedback connection (if
applicable).
•
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 the shaft gently downwards to the
maximum adjustment screw and hold it on.
•
If
maximum
pressure
setting
needs
adjustment, turn the maximum
rate
adjustment screw clockwise for increasing or
anti-clockwise for decreasing the maximum
pressure, until the desired pressure is
obtained. Release shaft.
•
Refit cap and “O”ring and reconnect
pressure feedback connection (if applicable).
When maximum and minimum pressure are set,
wire Modureg in circuit.
Checkout
After any adjustment, set appliance in operation
and observe through several complete cycles to
ensure that burner system components function
correctly.
IMPORTANT
Adjustments should be made by qualified
persons only.
The interface board is a signal conditioner
designed for the use in association a Honeywell
modulation coil V7335A (Modureg). The purpose is
to provide a linear conversion of a low DC voltage
or current (produced by control equipment) to a
requested control current or voltage for the
modulation coil (0-10 V-DC or 4-20 mA-DC).
Characteristics
Input signal
The interface board requires to be powered by a
230 VAC supply voltage.
Following control signals are available:
•
4 - 20 mA-DC with input protection for a con-
tinuous 200 mA signal (terminals 64-63).
•
0 - 5 V-DC with input protection for a con-
tinuous 35 V-DC signal signal (terminals 64-
65).
•
0 - 10 V-DC with input protection for a con-
tinuous 35 V-DC signal (terminals 64-66).
Note : Please ensure that the polarity '+' and '-' of
the control signal is correct, otherwise the PCB will
not operate correctly
Output signal.
The required output signal can
be obtained by
adjusting the selector switches on the printed
circuit board.
•
For output control signal of one modulation
coil V733SA (165mA)
Switch 1: "OFF"
Switch 2: "OFF"
OPERATION
Adjustment & Control signals.
General
A relay with potential free contacts (terminals 5 &
6) incorporated within the interface board, controls
the burner relay in the heater. This relay (burner on
relay) is triggered each time there is an increase of
the control current or voltage (room thermostat
Adjustment screw (7mm) for maximum pressure setting
Adjustment screw (9mm) for minimum pressure setting
Adjustment of modulation
Interface board
6. Commissioning & Testing cont.
