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
63
of
95
SECTION 5:
SAFETY DEVICE TESTING
5.1 TESTING OF SAFETY DEVICES
Periodic safety device testing is required to ensure that the control system and safety devices
are operating properly. The boiler control system comprehensively monitors all combustion-
related safety devices before, during and after the start sequence. The tests check to ensure
that the system is operating as designed.
Operating controls and safety devices should be tested on a regular basis or following service or
replacement. All testing must conform to local codes such as ASME CSD-1.
NOTES:
•
MANUAL and AUTO modes of operation are required to perform the following tests. For
a complete explanation of these modes, see Section 3:
Modes of Operation
in the
Benchmark 5000
– 6000 Operation and Maintenance Guide, OMM-0124 (GF-208)
.
•
It is necessary to remove the front door and side panels from the unit to perform the tests
described below.
WARNING!
Electrical voltages in this system include
120, 208, 460, 575 and 24
volts AC. Power must
be removed prior to performing wire removal or other test procedures that can result in
electrical shock.
5.2 LOW GAS PRESSURE TEST
The steps and pressure setting required to check the Low Gas Pressure switch are described
below. This switch is in the normally open (N.O.) position. Refer to Figure 5-1 for the location of
the switch and where to connect the water column manometer/gauge when performing the test.
The Low Gas Pressure switch is adjustable; the instructions below set it to the correct position.
LOW Gas Pressure Test Instructions
1. Shut off the
external
gas supply upstream to the unit by closing the external gas supply
ball valve (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
(see Figure 5-1) 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 5-1 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“
W.C. to 2 psi (0
– 14 kPa)
manometer.
5. Apply the reading of the manifold pressure taken in Step 15 of Section 4.5.1 (Natural Gas
train) and/or Section 4.5.2 (Propane gas train) and plug them into the following formulas,
which calculate the
minimum
allowable gas pressure:
•
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).
