Watts AERCO Benchmark BMK750 Operation And Service Manual page 75

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 5 – SAFETY DEVICE TESTING
LOW Gas Pressure Test Instructions: BMK3000 – 6000 Only
6.
Remove the cover from the Low Gas Pressure switch and set the dial indicator to 2 (the minimum).
7.
Open the external gas supply ball valve upstream of the unit.
8.
On the Controller, go to:
Manual Mode control.
Adjust the Air/Fuel Valve position to 100% using the + (Plus) and – (Minus) controls.
9.
10.
While the unit is firing, read the CO value on the combustion analyzer and slowly decrease the
incoming gas supply pressure until the CO reading is approximately 300 ppm.
11.
Take a reading of the inlet gas pressure. If the inlet pressure is below the minimum calculated in
step 5, above, then increase the pressure to match the calculated minimum.
12.
Slowly turn the indicator dial on the Low Gas Pressure switch until the unit shuts down due to a gas
pressure fault.
13.
Readjust the inlet gas pressure to what it was prior to the test.
14.
Press the Edge [i] Controller's CLEAR button to clear the fault.
15.
The fault message should clear, the red FAULT LED go off, and the unit should restart.
16.
For Dual Fuel units, repeat the previous procedure on the Propane gas train, starting with the
Propane Low Gas Pressure Switch.
MANUAL SHUT-
OFF VALVE
LOW Gas
Pressure Port
Install manometer here for
Low Gas Pressure test
Figure 5-2a: LOW and HIGH Gas Pressure Test Components – BMK3000 Shown
OMM-0145_A99 • GF-218 •
Main Menu → Diagnostics → Manual Mode
HIGH GAS
PRESSURE
SWITCH
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
9/18/2019
SSOV
TO
AIR/FUEL
VALVE
Alternative
Pressure Port
and then enable the
NATURAL
GAS INLET
LOW GAS
PRESSURE
SWITCH
LOW GAS
BALL VALVE
LOW Gas
(P/N 22310 shown)
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