High Gas Pressure Test; High Gas Pressure Test: Bmk750 - 2500 - Watts AERCO Benchmark BMK750 Operation And Service Manual

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 5 – SAFETY DEVICE TESTING

5.3 HIGH GAS PRESSURE TEST

Complete the instructions in Section 5.3.1 for BMK750 – 2500 units, or in Section 5.3.2 for
BMK3000 – 6000 units, which have different High Gas Pressure switches.
HIGH GAS PRESSURE TEST: BMK750 – 2500
5.3.1
To simulate a high gas pressure fault, refer to Figure 5-3a through Figure 5-3c and perform the
following steps:
HIGH Gas Pressure Test Instructions: BMK750 – 2500
1.
Close the leak detection ball valve located at the High Gas Pressure switch.
2.
Remove the 1/4" NPT plug from the High Gas pressure leak detection ball valve shown in Figures 5-
3a through 5-3c.
Install a 0 - 16" W.C. (0 – 4.0 kPa) manometer or gauge where the 1/4" plug was removed.
3.
4.
Slowly open the leak detection ball valve.
5.
On the Controller, go to:
6.
Enable the Manual Run control.
Set the valve position between 25% and 30% using the + (Plus) and – (Minus) controls.
7.
8.
With the unit running, monitor the gas pressure on the manometer installed in step 2 and record the
gas pressure reading.
9.
Slowly increase the gas pressure using the adjustment screw on the SSOV while counting the
number of turns you make.
10.
The FAULT indicator should start flashing and the unit should shut down and display a Fault
Lockout - Gas Pressure Fault message at approximately the value shown in Table 5-2 (the
pressure setting of the High Gas Pressure switch). If the unit does not trip off within 0.2" W.C. of the
pressure shown, the switch needs to be replaced.
TABLE 5-2: HIGH Gas Pressure, ± 0.2" W.C. (± 50 Pa)
Benchmark Model
BMK750/1000 FM & DBB Single-Fuel
BMK1500/2000 Single-Fuel
BMK1500/2000 DBB Single-Fuel
BMK1500/2000 Dual-Fuel
BMK1500/2000 DBB Dual-Fuel
BMK2500 FM & DBB Single-Fuel
BMK2500 Dual-Fuel
BMK2500 DBB Dual-Fuel
11.
Reduce the gas pressure by returning the SSOV adjustment screw back to its original position
before starting step 9 (the value recorded in step 8). This pressure should be within the range used
during combustion calibration, shown in Table 4-1 (Natural Gas) and Table 4-4 (Propane gas).
12.
Press the CLEAR button on the Edge [i] Controller to clear the fault.
13.
The fault message should clear, the FAULT indicator should go off and the unit should restart (if in
Manual mode).
14.
Upon test completion, close the ball valve and remove the manometer. Replace the 1/4" NPT plug
removed in step 2.
OMM-0145_A99 • GF-218 •
Main Menu → Diagnostics → Manual Mode
Natural Gas
4.7" W.C. (1.17 KPa)
4.7" W.C. (1.17 KPa)
4.7" W.C. (1.17 KPa)
4.7" W.C. (1.17 KPa)
3.5" W.C. (0.87 kPa)
3.0" W.C. (0.75 kPa)
7.0" W.C. (1,74 kPa)
7.0" W.C. (1,74 kPa)
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
9/18/2019
.
Propane
4.7" W.C. (1.17 KPa)
–
–
4.7" W.C. (1.17 KPa)
3.5" W.C. (0.87 kPa)
–
2.6" W.C. (0.65 kPa)
2.6" W.C. (0.65 kPa)
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