AERCO BMK 2.0 LN Natural Gas (SN G-11-1861 and above) - Manual (Page 74)

Chapter 6
Benchmark 2.0LN Low NOx Boiler
GF-123
Safety Device Tests Installation, Operation and Maintenance Manual OMM-0046_0E
Page 74 of 170 AERCO International Inc.● 100 Oritani Dr. ● Blauvelt, NY 10913. ● Ph: 800-526-0288 PR1 08/20/12
Figure 6-1: Low & High Gas Pressure Testing
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 and the FAULT indicator should go off. 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.
6.3 HIGH GAS PRESSURE TEST
To simulate a high gas pressure fault, refer to Figure 6-1 and proceed as follows:
1. Remove the 1/4“ plug from the leak detection ball valve shown in Figure 6-1.
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
4. Start the unit in Manual mode at a valve position (firing rate) between 25 and 30%.
5. Slowly increase the gas pressure using the adjustment screw on the SSOV (see Figure 4-3).
6. The unit should shut down and display a HIGH GAS PRESSURE fault message when the
gas pressure exceeds 4.7” W.C. The FAULT indicator should also start flashing.
7. Reduce the gas pressure back to 3.0” W.C.
8. Press the CLEAR button on the Control Box to clear the fault.
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 1.
SSOV
GAS
INLET
TO
AIR/FUEL
VALVE
MANUAL
SHUT-OFF
VALVE (Shown
Open)
1/4” NPT PLUG
(Install manometer here for
HIGH GAS PRESSURE TEST)
HIGH GAS
PRESSURE SWITCH
1/4” LEAK DETECTION
VALVE (Shown Closed)
1/4” NPT PLUG
(Install manometer here for
LOW GAS PRESSURE TEST)
1/4” BALL VALVE
(Shown Closed)
LOW GAS
PRESSURE SWITCH