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Benchmark 2500 - 3000 Boilers
CHAPTER 3 – OPERATION
Page
48
of
207
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0094_0F
09/30/2015
Ph.: 800-526-0288
GF-137
3.10 START SEQUENCE
When the Control Box ON/OFF switch is set to the
ON
position, it checks all pre-purge safety
switches to ensure they are closed. These switches include:
•
Safety Shut-Off Valve (SSOV) Proof of Closure (POC) switch
•
Low Water Level switch
•
High Water Temperature switch
•
High Gas Pressure switch
•
Low Gas Pressure switch
•
Blower Proof switch
•
Blocked Inlet switch
If all of the above switches are closed, the
READY
light above the ON/OFF switch will light and
the unit will be in the Standby mode.
When there is a demand for heat, the following events will occur:
NOTE
If any of the Pre-Purge safety device switches are open, the
appropriate fault message will be displayed. Also, the appropriate
messages will be displayed throughout the start sequence, if the
required conditions are not observed.
1.
The
DEMAND
LED status indicator will light.
2.
The unit checks to ensure that the Proof of Closure (POC) switch in the downstream
Safety Shut-Off Valve (SSOV) is closed. See Figure 3-3 for SSOV location.
Figure 3-3a:
BMK 2500:
SSOV Location
NATURAL
GAS INLET
TO
AIR/FUEL
VALVE
HIGH GAS
PRESSURE
SWITCH
MANUAL
SHUT-OFF
VALVE
LOW GAS
PRESSURE
SWITCH
SSOV