Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 5
– SAFETY DEVICE TESTING
OMM-0145_A99
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of
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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.
5.3.1
HIGH GAS PRESSURE TEST: BMK750
–
2500
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.
3.
Install a
0 -
16” W.C. (0 – 4.0 kPa)
manometer or gauge where the 1/4" plug was removed.
4.
Slowly open the leak detection ball valve.
5.
On the Controller, go to:
Main Menu
→
Diagnostics
→
Manual Mode
.
6.
Enable the
Manual Run
control.
7.
Set the valve position
between 25% and 30%
using the
+
(Plus) and
–
(Minus) controls.
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
Natural Gas
Propane
BMK750/1000 FM & DBB Single-Fuel
4.7” W.C. (1.17 KPa) 4.7” W.C. (1.17 KPa)
BMK1500/2000 Single-Fuel
4.7” W.C. (1.17 KPa) –
BMK1500/2000 DBB Single-Fuel
4.7” W.C. (1.17 KPa) –
BMK1500/2000 Dual-Fuel
4.7” W.C. (1.17 KPa) 4.7” W.C. (1.17 KPa)
BMK1500/2000 DBB Dual-Fuel
3.5” W.C. (0.87 kPa)
3.5” W.C. (0.87 kPa)
BMK2500 FM & DBB Single-Fuel
3.0” W.C. (0.75 kPa)
–
BMK2500 Dual-Fuel
7.0” W.C. (1,74 kPa)
2.6” W.C. (0.65 kPa)
BMK2500 DBB Dual-Fuel
7.0” W.C. (1,74 kPa)
2.6” W.C. (0.65 kPa)
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.
