Benchmark 1.5ln low nox boiler, Gf-120 – AERCO BMK 1.5 LN July 2011 User Manual
Page 39

CHAPTER 3: CONTROL PANEL OPERATION
PR2: 05/09/12 Page
39 of 152
Benchmark 1.5LN Low NOx Boiler
Operation and Maintenance Manual
OMM-0041_0D
GF-120
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
Figure 3-3: SSOV Location
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.
c) The gas Safety Shut-Off Valve (SSOV) is energized (opened) allowing gas to flow
into the Air/Fuel Valve.
TO
AIR/FUEL
VALVE
GAS INLET
SSO
MANUAL GAS
SHUT-OFF
VALVE