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Benchmark 750-3000 Boiler Installation & Startup Manual
SECTION 5 – SAFETY DEVICE TESTING
HIGH Gas Pressure Test Instructions: BMK 3000 ONLY
8. Slowly increase the manifold gas supply pressure by turning the Gas Pressure Adjustment
Screw in the Downstream SSOV (Figure 4-3) while reading the CO level on the
combustion analyzer. Adjust the manifold pressure until the CO reading is approximately
300 ppm. Note the number of turns you make, as you will turn it back to its original position
in step 10, below.
9. Take a reading of the manifold gas pressure. If the manifold pressure is greater than the
maximum calculated in step 3, then use the Gas Pressure Adjustment Screw to decrease
the manifold pressure until it is at the maximum allowed.
10. Press the RESET button on the High Gas Pressure switch (see Figure 5-4, below).
11. Slowly turn the indicator dial on the High Gas Pressure switch until the unit shuts down due
to a gas pressure fault. This is the setpoint.
12. Readjust the manifold gas supply pressure to what it was before it was increased in step 7.
13. Press the CLEAR button on the control panel to clear the fault.
14. Upon test completion, close the ball valve and remove the manometer fitting from the port,
and then turn the port screw clockwise till the port is closed.
MANUAL SHUT-
OFF VALVE
HIGH Gas
Pressure Port
Install manometer
here for High Gas
Pressure test
Figure 5-4: BMK 3000 HIGH Gas Pressure Test Components
OMM-0121_D • GF-205 • 5/9/2019
SSOV
TO
AIR/FUEL
VALVE
HIGH GAS
BALL VALVE
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
NATURAL
GAS INLET
HIGH GAS
PRESSURE
SWITCH
LOW GAS
PRESSURE
SWITCH
Alternative
HIGH Gas
Pressure Port
Page 85 of 122
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