AERCO BMK 1.5 LN Dual Fuel Feb 2013 - Manual (Page 68)

CHAPTER 6: SAFETY DEVICE TESTING
Page 68 of 162 PR2: 05/09/12
Benchmark 1.5LN Dual-Fuel Low NOx Boiler
Operation and Maintenance Manual
OMM-0041_0C
GF-121
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
Figure 6-1a: Low Gas Pressure Testing
6.3 PROPANE GAS LOW GAS PRESSURE FAULT TEST
Refer to Figure 6-1a and ensure that the leak detection ball valve located at the high gas
pressure switch is closed.
1. Ensure that the Fuel Selector Switch (Figure 4-3) is set to the PROPANE position.
2. Remove the 1/4“ plug from the ball valve at the low gas pressure switch shown in the
middle right portion of Figure 6-1a.
3. Install a 0 – 16 “ W.C. manometer or a W.C. gauge where the 1/4" plug was removed.
4. Slowly open the ball valve near the PROPANE low gas pressure switch.
5. Place the unit in Manual Mode and adjust the air/fuel valve position (% open) between
25% and 30%.
6. While the unit is firing, slowly close the external manual gas shut-off valve.
7. The unit should shut down and display a LOW GAS PRESSURE fault message at
approximately 1.0” W.C. The FAULT indicator should also start flashing.
8. Fully open the external manual gas shut-off valve and press the CLEAR button on the
Control Box.
9. The fault message should clear and the FAULT indicator should go off. The unit
should restart.
10. Upon test completion, close the ball valve and remove the manometer. Replace the
1/4“ plug removed in step 2.
NATURAL
GAS SSOV
PROPANE
GAS SSOV
NATURAL
GAS INLET
PROPANE
GAS INLET
MANUAL
SHUTOFF
VALVE
PROPANE GAS HIGH GAS
PRESSURE SWITCH
NATURAL GAS LOW
GAS PRESSURE
SWITCH
LEAK
DETECTION
BALL VALVE
NATURAL GAS HIGH
GAS PRESSURE
SWITCH
PROPANE LOW
GAS PRESSURE
SWITCH
1/4” PLUG & BALL VALVE
(Install manometer here for
NATURAL GAS Low
Pressure Test)
1/4” PLUG & BALL VALVE
(Install manometer here for
PROPANE Low Pressure
Test)