Watts Aerco Benchmark OMM-0117 Operation And Maintenance Manual page 73

Benchmark 5000-6000 Operation & Maintenance Manual
SECTION 5 – TROUBLESHOOTING GUIDE
TABLE 5-1: Boiler Troubleshooting Procedures
FAULT
INDICATION
1. Remote setpoint signal not present:
Not yet installed.
Wrong polarity.
Signal defective at source.
REMOTE
Broken or loose wiring.
SETPT
2. Signal is not isolated (floating) if 4 to 20 mA.
SIGNAL FAULT
3. C-More Controller signal type selection switches
not set for correct signal type (voltage or
current).
1. Defective Flame Detector.
2. SSOV not fully closed.
RESIDUAL
FLAME
SSOV FAULT
See SSOV SWITCH OPEN
DURING
PURGE
1. SSOV switch closed for 15 seconds during run.
SSOV FAULT
DURING RUN
1. SSOV relay failed on IGST board.
2. Floating Neutral.
SSOV RELAY
FAILURE
3. Hot and Neutral reversed at SSOV.
OMM-0118_B • GF-203 • 5/9/2019
PROBABLE CAUSES
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
CORRECTIVE ACTION
1. Check I/O Box to ensure signal is hooked up.
Hook up if not installed.
If installed, check polarity.
Measure signal level.
Check continuity of wiring between source and unit.
2. Check signal at source to ensure it is isolated.
3. Check DIP switch on PMC board to ensure it is set correctly for the
type of signal being sent. Check control signal type set in
Configuration menu.
1. Replace Flame Detector.
2. Check open/close indicator window of Safety Shut-Off Valve (SSOV)
and ensure that the SSOV is fully closed. If not fully closed, replace
the valve and or actuator.
Close the 2" Gas Shut-Off Valve downstream of SSOV (Figure 5-1).
Install a manometer or gauge at the leak detection port between the
SSOV and Gas Shut Off Valve. If a gas pressure reading is observed
replace the SSOV Valve and/or Actuator.
1. Replace actuator.
1. Press CLEAR button and restart unit. If fault persists, replace
Ignition/Stepper (IGST) Board.
2. The Neutral and Earth Ground are not connected at the source and
therefore there is a voltage measured between the two. Normally this
measurement should be near zero or no more than a few millivolts.
3. Check SSOV power wiring.
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