Instruction Manual
Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 6 – SAFETY DEVICE TESTING
OMM-0082_0J AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 79 of 192
GF-130 Ph.: 800-526-0288 05/21/2014
6.3 HIGH GAS PRESSURE TEST
The instructions below apply to both the Natural Gas and Propane gas trains.
To simulate a high gas pressure fault, refer to Figure 6-1B and perform the following steps:
High Gas Pressure Test
1. Remove the 1/4“ plug from the leak detection ball valve at the High Gas Pressure switch,
shown in Figure 6-1B.
2. Install a 0 – 16” W.C. manometer (or W.C. gauge) where the 1/4” plug was removed.
3. Slowly open the leak detection ball valve near the High Gas Pressure switch.
4. Start the unit in Manual mode at a valve position (firing rate) between 25 and 30%.
5. With the unit running, monitor the gas pressure on the manometer installed in step 2 and
record the gas pressure reading.
6. Slowly increase the gas pressure using the adjustment screw on the SSOV (see Figure
4-3 in Chapter 4).
7. 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: 4.7” W.C.
• BMK 750 – PROPANE gas train: 4.7” W.C.
• BMK 1000 – PROPANE gas train: 10.5” W.C.
8. Reduce the gas pressure back to the value recorded in step 5. This pressure should be
within the range of
• BMK 750 & 1000 – NATURAL GAS gas trains: 2.0” W.C. ± 0.4” W.C.
• BMK 750 – PROPANE gas train: 3.9” W.C. ± 0.2” W.C.
• BMK 1000 – PROPANE gas train: 7.4” W.C. ± 0.2” W.C.
9. Press the CLEAR button on the Control Box to clear the fault.
10. The fault message should clear and the FAULT indicator should go off. The unit should
restart.
11. Upon test completion, close the ball valve and remove the manometer. Replace the
1/4“plug removed in step 1.
Figure 6–1B: High Gas Pressure Test – Natural Gas gas train shown
SSOV
GAS INLET
TO AIR/FUEL
VALVE
HIGH GAS PRESSURE LEAK
DETECTION BALL VALVE
1/4” NTP PLUG
(Install manometer
here for High Gas
Pressure Test)
MANUAL SHUT-OFF
VALVE
HIGH GAS
PRESSURE SWITCH
LOW GAS
PRESSURE SWITCH