Watts AERCO Benchmark OMM-0136 - Page 59

Benchmark Platinum-Edge [II]: Operation-Service Manual
SECTION 5 – SAFETY DEVICE TESTING
OMM-0137_E • GF-211 • 12/13/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 59 of 153
LOW Gas Pressure Test Instructions: BMK3000 – 6000 Only
BMK5000 &
6000
FM Natural Gas pressure →____ x 0.5 + 6.0 = ______ min gas pressure
Propane Gas pressure →____ x 0.5 + 3.7 = ______ min gas pressure
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: Main Menu → Diagnostics → Manual Run and then enable the
Manual Mode control.
9. Adjust the Air/Fuel Valve position to 100% using the + (Plus) and – (Minus) controls.
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 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.
TO
AIR/FUEL
VALVE
MANUAL SHUT-
OFF VALVE
SSOV
LOW Gas
Pressure Port
Install manometer here for
Low Gas Pressure test
LOW GAS
PRESSURE
SWITCH
HIGH GAS
PRESSURE
SWITCH
Alternative
LOW Gas
Pressure Port
LOW GAS
BALL VALVE
NATURAL
GAS INLET
(P/N 22310 shown)