CleaverBrooks CBLE, Руководство по эксплуатации и обслуживанию

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750-91 (revised 2009)
Model CB-LE Packaged Boiler Manual 6-11
6.15 — Gas Pilot Flame Adjustment
Since the adjustment of the air switch may be made either during the damper closed or damper open position of
pre-purge, it is also possible to make the adjustment with the relay stopped in the damper open position in a similar
manner to the adjustment of the combustion air proving switch described in Section 6.13.
After making the adjustment, recycle the control to be sure that normal operation is obtained. The TEST switch
must be set to RUN position.
6.15 — Gas Pilot Flame Adjustment
The size of the gas pilot flame is regulated by adjusting the gas flow through the pilot gas regulator and the pilot
adjusting cock on the front of the burner. The flame must be sufficient to ignite the main flame and to be seen by
the flame detector. But an extremely large flame is not required. An overly rich flame can cause sooting or carbon
buildup on the flame detector. Too small a flame can cause ignition problems.
Although it is possible to visibly adjust the size of the pilot flame, it is preferable to obtain a microamp or voltage
reading of the flame signal.
The correct voltage or microamp readings can be found in the information supplied with the flame safeguard sys-
tem.
The program relay used may be of the type that provides message information that includes a constant flame signal
of DC voltage. In this case a separate DC voltmeter is not required.
6.15.1 — Measure and Adjust Pilot
1.
When making a pilot adjustment, turn the manual-automatic switch to “manual” and the manual flame control
to “close.”
2.
Open both the cutoff cock and the pilot adjusting cock. The main gas cock should remain closed.
The regulator in the pilot line, if provided, is to reduce the gas pressure to suit the pilot’s requirement of
between 5” to 10” WC. Regulator adjustment is not critical, however, with a lower pressure the final adjustment
of the pilot flame with adjusting cock is less sensitive.
3.
Connect the micro-ammeter.
4.
Turn the burner switch on. Let the burner go through the normal pre-purge cycle. When the ignition trial
period is signaled, set the test switch to the TEST position to stop the sequence.
5.
If the pilot flame is not established within 10 seconds, turn off the burner switch. Repeat the lighting attempt.
6.
When the pilot flame is established, and with the pilot adjusting cock wide open, remove the flame detector
from the burner plate. The pilot flame can then be observed through this opening.
NOTE: On an initial starting attempt, portions of the fuel lines may be empty and require “bleeding” time. It is better
to accomplish this with repeated short lightning trial periods with intervening purge periods than to risk prolonged fuel
introduction. If the pilot does not light after several attempts, check all components of the pilot system.