Table of Contents
Advertisement
Available languages
Available languages
6.4
Adjustments prior to ignition
In addition, the following adjustments must also be made:
➤ Slowly open the manual valves situated upstream from the
gas train.
➤ Adjust the minimum gas pressure switch (Fig. 26) to the start
of the scale.
➤ Adjust the maximum gas pressure switch (Fig. 25) to the end
of the scale.
➤ Adjust the air pressure switch (Fig. 24) to the start of the
scale.
➤ Purge the air from the gas line. We recommend using a plas-
tic tube routed outside the building and to purge air until gas
is smelt.
➤ Fit a U-type pressure gauge or a differential pressure gauge
(Fig. 23), with socket (+) on the gas pressure of the pipe
coupling and (-) in the combustion chamber. The manometer
readings are used to calculate MAX burner output.
➤ Connect two lamps or testers to the two gas line solenoids to
check the exact moment in 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.
Before starting up the burner, it is good practice to
adjust the gas train so that ignition takes place in
conditions of maximum safety, i.e. with gas deliv-
CAUTION
ery at the minimum.
6.5
Burner start-up
Close the remote controls and put the selector on the boiler's
main panel to " ON ".
Make sure that the lights or testers connected to the solenoids, or
the pilot lights on the solenoids themselves, indicate that no volt-
6.6
Burner ignition
The burner should light after having performed the above steps.
If after completing the starting cycle the flame does not appear
and the control box goes into lockout, reset it and wait for a new
ignition attempt.
If ignition 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 ignition delivery.
6.7
Combustion air adjustment
Fuel/combustion air synchronisation is done with the relevant
servomotors (air and gas) by logging a calibration curve by
means of the electronic cam.
It is advisable, to reduce the loss and for a wide calibration field,
to adjust the servomotors to the maximum of the output used, the
nearest possible to the maximum opening (90°).
On the gas butterfly valve, fuel step according to the burner out-
put required, with servomotor completely open, is carried out by
the pressure stabiliser placed on the gas train.
The values shown in Tab. I can be used as a reference for cali-
brating the combustion well.
20124993
Start-up, calibration and operation of the burner
20125463
age is present. If voltage is present, stop the burner immediately
and check the electrical connections.
When the limit thermostat (TL) closes, the " CALL FOR HEAT " )
signal must come on (if present on the main panel) and the burn-
er will begin its starting cycle.
The arrival of gas at the pipe coupling is evidenced by the U-
shaped pressure gauge (Fig. 23) or else with the aid of a digital
pressure gauge placed on the pressure test point under the cou-
pling.
If further burner lockouts occur, refer to the "Reset procedure" in
the equipment manual supplied. with the boiler's main panel.
Once the burner has fired, now proceed with global calibration
operations.
EN 676
Theoretical max
CO
GAS
2
0 % O
2
G 20
11.7
G 25
11.5
G 30
14.0
G 31
13.7
22
GB
Air excess
Max. output.
Max. output.
λ ≤1.2
λ ≤1.3
CO
% Calibration
2
λ = 1.3
λ = 1.2
9.7
9
9.5
8.8
11.6
10.7
11.4
10.5
Fig. 23
CO
mg/kWh
≤ 1000
≤ 1000
≤ 1000
≤ 1000
Tab. I
Advertisement
Chapters
Table of Contents
