Benchmark 5000-6000 Boiler Installation & Startup Manual
SECTION 5:
SAFETY DEVICE TESTING
OMM-0123_E
• GF-207 • 12/17/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page
64
of
95
LOW Gas Pressure Test Instructions
7. Open the external gas supply ball valve upstream of the unit.
8. Place the unit in MANUAL mode and adjust the Air/Fuel Valve position (% open) to
100%
.
9. 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
.
10. 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.
11. Slowly turn the indicator dial on the
Low Gas Pressure
switch until the unit shuts down
due to a gas pressure fault.
12. Readjust the inlet gas pressure to what it was prior to the test.
13. Press the
CLEAR
button on the Control Panel to clear the fault.
14. The fault message should clear and the
FAULT
indicator should go off. The unit should
now restart.
15. For Dual Fuel units, repeat the previous procedure on the PROPANE gas train, starting
with the PROPANE Low Gas Pressure Switch, shown in the bottom-half of Figure 5-1.
Figure 5-1:
Low Gas Pressure Switch Locations & Test Ports
MANUAL
SHUT-OFF
VALVE
TO
AIR/FUEL
VALVE
NATURAL GAS Low Gas
Pressure Test Port
Install manometer here
Alternative location for manometer
if hose barb is preferred
Alternative
location
PROPANE Low Gas
Pressure Test Port
Install manometer here
Dual Fuel gas train showing both Natural Gas and
Propane gas trains
