Instruction Manual

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 6 – SAFETY DEVICE TESTING
Page 78 of 192 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0082_0J
05/21/2014 Ph.: 800-526-0288 GF-130
6.2 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 on both the Natural Gas and Propane gas trains.
Low Gas Pressure Fault Test
1. Remove the 1/4“ plug from the leak detection ball valve at the Low Gas Pressure switch,
shown in Figure 6-1A.
2. Install a 0 – 16“ W.C. manometer or a W.C. gauge where the 1/4" plug was removed.
3. Slowly open the ball valve near the Low Gas Pressure switch.
4. Place the unit in Manual Mode and adjust the Air/Fuel Valve position (% open) between
25 and 30%.
5. While the unit is firing, slowly close the external manual gas shut-off valve.
6. The unit should shut down and display a GAS PRESSURE fault message, and the
FAULT indicator should also start flashing at the following approximate pressures:
• BMK 750 & 1000 – NATURAL GAS gas trains: 2.6” W.C.
• BMK 750 – PROPANE gas train: 4.4” W.C.
• BMK 1000 – PROPANE gas train: 7.5” W.C.
7. Fully open the external manual gas shut-off valve and press the CLEAR button on the
Control Box.
8. The fault message should clear, the FAULT indicator should go off and the unit should
restart.
9. Upon test completion, close the ball valve and remove the manometer. Replace the 1/4“
plug removed in step 1.
Figure 6-1A: Low Gas Pressure Fault Test – Natural Gas gas train shown
SSOV
GAS INLET
TO AIR/FUEL
VALVE
LOW GAS PRESSURE
LEAK DETECTION BALL VALVE
(shown closed)
1/4” NTP PLUG
(Install manometer
here for Low Gas
Pressure Test)
HIGH GAS PRESSURE
SWITCH
LOW GAS PRESSURE SWITCH
MANUAL SHUT-OFF
VALVE
HIGH GAS PRESSURE
LEAK DETECTION
BALL VALVE