Benchmark Platinum-Edge: Operation-Service Manual
SECTION 5 – SAFETY DEVICE TESTING
OMM-0137_D • GF-211
•
7/16/2019
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Figure 5-1c: BMK 2500 LOW Gas Pressure Test Components
5.2.2 LOW GAS PRESSURE TEST: BMK 3000 – 6000 Only
To simulate a low gas pressure fault on BMK 3000 – 6000 units, refer to Figure 5-2a and 5-2b,
below, and perform the following steps:
LOW Gas Pressure Test Instructions: BMK 3000 – 6000 Only
1. Close the
external
gas supply ball valve upstream of the unit (not shown).
2. Remove the front panel from the boiler to access the gas train components.
3. Locate the port on the top of the Low Gas Pressure switch and loosen the screw inside a
few turns to open it.
Do not remove this screw completely.
Alternatively, you can remove
the 1/4 inch plug shown in Figure 5-2a and 5-2b and install a hose barb fitting in that
location.
4. Attach one end of the plastic tubing to the port or barb fitting and the other end to a
0 –
16”
W.C. (0 – 4.0 kPa)
manometer.
5. Apply the reading of the manifold pressure taken in Step 21 of Section 4.4.1 (Natural Gas
units) or Step 21 of Section 4.4.2 (Propane units) and plug it into the following formula,
which calculates the minimum allowable gas pressure:
BMK 3000
FM Natural Gas pressure
____ x 0.5 + 0.7 = ______ min gas pressure
DBB Natural Gas pressure
____ x 0.5 + 1.6 = ______ min gas pressure
Propane Gas pressure
____ x 0.5 + 0.6 = ______ min gas pressure
BMK 5000
& 6000
FM Natural Gas pressure
____ x 0.5 + 6.0 = ______ min gas pressure
Propane Gas pressure
____ x 0.5 + 3.7 = ______ min gas pressure
SSOV
TO
AIR/FUEL
VALVE
LOW GAS
PRESSURE
SWITCH
MANUAL
SHUT-OFF
VALVE
LOW GAS BALL VALVE
1/4” NPT PLUG
Install manometer
here for LOW gas
pressure fault test.
NATURAL
GAS INLET
HIGH GAS PRESSURE
SWITCH
(P/N 22190 shown)
