CHAPTER 3: CONTROL PANEL OPERATION
PR2: 04/22/13 Page
37
of
158
Benchmark 2.0LN Dual-Fuel Low NOx Boiler
Operation and Maintenance Manual
OMM-0052_0E
GF-127
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
•
Ph: 800-526-0288
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. Figure 3-3 shows the Natural Gas SSOV
location for a Factory Mutual (FM) Gas Train.
3. With all required safety device switches closed, a purge cycle will be initiated and the
following events will occur:
a) The Blower relay energizes and turns on blower.
b) The Air/Fuel Valve rotates to the full-open purge position and closes purge position
switch. The dial on the Air/Fuel Valve (Figure 3-4) will read 100 to indicate that it is
full-open (100%).
Figure 3-3: SSOV Locations
4. Next, the blower proof switch on the Air/Fuel Valve (Figure 3-5) closes. The display
will show
Purging
and indicate the elapsed time of the purge cycle in seconds.
5. Upon completion of the purge cycle, the Control Box initiates an ignition cycle and the
following events occur:
a) The Air/Fuel Valve rotates to the low-fire ignition position and closes the ignition
switch. The dial on the Air/Fuel Valve (Figure 3-6) will read between 25 and 35 to
indicate that the valve is in the low-fire position.
b) The igniter relay is activated and provides ignition spark.
PROPANE
SSOV
NATURAL
GAS SSOV
TO AIR/FUEL
VALVE
MANUAL
SHUT-OFF
VALVE
PROPANE
GAS
INLET
NATURAL
GAS
INLET
