Start-up, calibration and operation of the burner
29
20019893
GB
5.7.7
High fire fan air damper
Turn "MANUAL" switch (Fig. 37) to “+”, increase output until the
high fire position is acheived. The fan damper position is set by ad-
justing the cam 4 position (Fig. 33, page 27) of the servomotor.
5.7.8
Low oil pressure switch
The low oil pressure switch (Fig. 38) is factory set to 145 PSI
(10 bar). If the oil pressure goes down this value in the delivery pip-
ing, the pressure switch stops the burner.
Burner starts again automatically if the pressure goes above
145 PSI (10 bar) after burner restart.
5.8
Burner starting (gas adjustment)
5.8.1
Burner firing
Having completed the checks indicated in the previous heading,
the pilot of the burner should fire.
If the motor starts but the flame does not appear and the flame
safeguard goes into lock-out, reset and wait for a new firing at-
tempt.
Pilot adjustment has been illustrated on page 27.
Having adjusted the pilot, reconnect the main valve and ignite the
main flame; it might require several attempts to purge the air from
the gas lines or to adjust the valve with little gas.
Once the burner has fired, now proceed with calibration operations.
5.8.2
Burner calibration
The optimum calibration of the burner requires an analysis of the
flue gases at the boiler outlet.
Adjust successively:
➤
Firing output
➤
Maximum burner output
➤
Minimum burner output
➤
Intermediate outputs between low and high fire
➤
Air pressure switch
➤
Minimum gas pressure switch
5.8.3
Firing output
Pilot adjustment has been illustrated on page 27.
5.8.4
Maximum burner output
Maximum output of the burner must be set within the “Firing rates”
range shown at page 9. In the above instructions we left the burner
running in MIN. output operation.
➤
Move the selector 21)(Fig. 5, page 12) to “MAN” position.
➤
Move the selector 45)(Fig. 5) to position “+”, increase output,
until the servomotor has opened the air damper and the gas
butterfly valve to 90°.
Gas calibration
Measure the gas delivery at the meter.
A guideline indication can be calculated from the Tab. G, page 22,
simply read off the gas pressure on the manometer (Fig. 28) and
follow the instructions at page 22.
➤
If firing rate needs to be adjusted, increase or decrease gas
regulator outlet pressure.
Adjusting air delivery
Progressively adjust the end profile of cam 4)(Fig. 39) by turning
the cam adjustment screws 5 & 6 as they appear through the ac-
cess opening).
➤
Turn the screws clockwise to increase air delivery.
➤
Turn the screws counter-clockwise to reduce air delivery.
-
+
-
Fig. 38
D10627
