10 purge switch open during purge, Benchmark 1.5ln low nox boiler, Gf-120 – AERCO BMK 1.5 LN July 2011 User Manual
Page 68

CHAPTER 6: SAFETY DEVICE TESTING
Page
68 of 152 PR2: 05/09/12
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
4. Remove the cover from the SSOV by loosening the screw shown in Figure 6-4. Lift off the
cover to access the terminal wiring connections.
5. Disconnect wire #148 from the SSOV to “open” the proof of closure switch circuit.
6. The unit should fault and display SSOV SWITCH OPEN.
7. Replace wire #148 and press the
CLEAR button.
8. Set the
ON/OFF switch to ON to start the unit.
9. Remove the wire again when the unit reaches the purge cycle and PURGING is displayed.
10. The unit should shut down and display SSOV FAULT DURING PURGE.
11. Replace the wire on the SSOV and press the
CLEAR button. The unit should restart.
ACTUATOR
COVER
SCREW
SSOV
ACTUATOR
COVER
Figure 6-4: SSOV Actuator Cover Location
6.10 PURGE SWITCH OPEN DURING PURGE
The Purge Switch (and Ignition Switch) is located on the Air/Fuel Valve. To check the switch,
proceed as follows:
1. Set the unit’s ON/OFF switch to the
OFF position. Place the unit in manual mode and set the
valve position between 25% and 30%.
2. Remove the Air/Fuel Valve cover by rotating the cover counterclockwise to unlock it and
then lift up (see Figure 6-5).
3. Remove one of the two wires (#171 or #172) from the Purge Switch (Figure 6-6).
4. Initiate a unit start sequence.
5. The unit should begin it’s start sequence, then shut down and display PRG SWITCH OPEN
DURING PURGE.
6. Replace the wire on the Purge Switch and depress the
CLEAR button. The unit should
restart.