CleaverBrooks FLX 1250, Руководство по эксплуатации, обслуживанию и запасным частям

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Chapter 5 Adjustment Procedures
5-4 750-364
Recycle the program relay to be sure that normal operation is
obtained. Return the test switch to the RUN position.
F. GAS PILOT FLAME ADJUSTMENT
The size of the gas pilot flame is regulated by adjusting the
gas flow through the pilot gas regulator. 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
igniting electrode. 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 system.
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.
G. GAS PRESSURE AND FLOW
INFORMATION
Because of variables in both the properties of gas and the
supply system, it will be necessary to regulate the pressure of
the gas to a level that produces a steady, dependable flame
that yields highest combus tion efficiency at rated
performance yet prevents overfiring. Once the optimum
pressure has been established, it should be recorded and
periodic checks made to verify that the regulator is holding
the pressure at this level. Occasional modification in fuel
composition or pressure by the supplier may, at times, require
readjustment to return the burner to peak efficiency.
Pressure
The gas supplied must provide not only the quantity of gas
demanded by the unit, but must also be at a pressure high
enough to overcome the pressure-loss due to the frictional
resistance imposed by the burner system and the control
valves.
Modulated Firing
Range
Firing Rate
100%
0%
Minimum Input
(Low Fire)
Burner Off
In
crea
si
ng
Falling Temp.
or Pressure
“ON - OFF”
Differential
Rising Temp.
or Pressure
In
crea
si
ng
Increasing
(Burner ON)
(Burner OFF)
(Burner OFF)
Boiler Temp.or Press
High Limit Control
Safety Shutdown
Operating Limit Control
Response
Modulation Control Response
D
C
B
A