Safety Device Testing; Testing Of Safety Devices; Low Gas Pressure Test - Watts AERCO CFR 1500 Operation And Service Manual

SECTION 5 SAFETY DEVICE TESTING
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 following 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.
NOTE: Manual and Auto modes of operation are required to perform the following tests. For a full explanation,
see Section 3.1: Manual Mode in the Edge Controller Manual (OMM-0139).
NOTE: It is necessary to remove the front door and side panels to perform the tests described below.
Electrical voltages up to 120 VAC and 24 volts AC may be used in this equipment. Shut off all power before
performing wire removal or other procedures that can result in electrical shock. Failure to turn off power as
directed may result in death, serious bodily injury, or damage to equipment or other property

5.2 Low Gas Pressure Test

To simulate a low gas pressure fault on CFR units:
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 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 4-1: 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 – 16" W.C. (0
– 4.0 kPa) manometer.
5. Remove cover from Low Gas Pressure switch and set the dial indicator to 2.6" (the minimum
allowed low gas pressure switch setting).
6. Open the external gas supply ball valve upstream of the unit.
Main Menu → Diagnostics → Manual Mode
7. Go to:
8. Adjust the Air/Fuel Valve position to 100% using the + (Plus) and – (Minus) controls.
9. While the unit is firing, read the CO value on the combustion analyzer and slowly decrease the
incoming gas supply pressure until either the unit shuts down due to a gas pressure fault OR the CO
reading reaches 250 ppm, whichever happens first.
10. If CO reads 250 ppm before the unit shuts down due to a gas pressure fault, slowly turn the
indicator dial on the Low Gas Pressure switch until the unit shuts down. This is the setpoint.
11. Slowly turn indicator dial on Low Gas Pressure switch until unit shuts down due to pressure fault.
12. Readjust the inlet gas pressure to what it was prior to the test.
13. Press the Edge Controller's CLEAR button to clear the fault.
14. The fault message should clear, the red FAULT LED go off, and the unit should restart.
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and enable Manual Mode.
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