MIN GAS PRESSURE SWITCH
(A)
(C)
AIR PRESSURE SWITCH
D3855
(B)
ADJUSTMENTS BEFORE FIRST FIRING
!
THE FIRST FIRING MUST BE CARRIED OUT
BY QUALIFIED PERSONNEL WITH THE
RIGHT INSTRUMENTS.
Adjustment of the combustion head, and air and
gas deliveries has been illustrated on page 9.
In addition, the following adjustments must also
be made:
-
open manual valves up-line from the gas
train.
-
Adjust the minimum gas pressure switch to
the start of the scale (A).
-
Adjust the air pressure switch to the start of
D3854
the scale (B).
-
Purge the air from the gas line.
Continue to purge the air (we recommend
using a plastic tube routed outside the build-
ing) until gas is smelt.
-
Assemble a pressure gauge (C) on the gas
pressure socket of the pipe coupling.
The manometer readings are used to calcu-
late burner power using the tables on page 6
and 7.
-
Connect two lamps or testers to the two gas
line solenoid valves VR and VS, to check the
exact moment at which voltage is supplied.
This operation is unnecessary if each of the
two solenoid valves is equipped with a pilot
light that signals voltage passing through.
-
Fan air damper: leave at the factory setting.
D3841
Before starting up the burner, it is good practice
to adjust the gas train so that firing takes place
in conditions of maximum safety, i.e. with gas
delivery at the minimum.
BURNER START-UP
Close the control devices.
As soon as the burner starts check the direction
of rotation of the fan blade, looking through the
flame inspection window 18)(A)p.4.
Make sure that the lamps or testers connected
to the solenoids, or pilot lights on the solenoids
themselves, indicate that no voltage is present.
If voltage is present, then immediately stop the
burner and check electrical connections.
BURNER FIRING
Having completed the checks indicated in the
previous heading, ignition of the burner should
be achieved. If the motor starts but the flame
does not appear and the control box goes into
lockout, reset and wait for a new firing attempt.
If firing is still not achieved, it may be that gas is
not reaching the combustion head within the
safety time period of 3 seconds. In this case
increase gas firing delivery.
The arrival of gas to the pipe coupling is shown
by the pressure gauge (C).
Once firing has taken place, proceed with global
burner calibration operation.
11
ATTENTION