Orion System MODGAS-XWR - Manual (Page 22)

TROUBLESHOOTING
MODGAS-XWR Technical Guide 22
Troubleshooting Alarms
Mechanical Failure:
• Check relay outputs on the MODGAS-XWR for 24
VAC output.
• Verify the SAT OPTIONS jumper settings on the
MODGAS-XWR for Supply Air Temperature Sensor.
• Verify gas valve LED is solid. Try forcing valves (refer
to Force Screens in this guide).
• Verify that the Supply Air Temperature Sensor is
connected to SAT and GND on the MODGAS-XWR
(stand-alone mode) or to AI2 and GND on the Main
Controller (communicating mode).
• Verify Supply Air Temperature Sensor probe is
mounted correctly in supply duct.
• Remove SAT and GND wiring from the MODGAS-
XWR and ohm sensor out (this may indicate open or
failed wiring). Refer to chart in back of this guide for
readings.
Supply Air Temperature Failure:
• Verify that the Supply Air Temperature Sensor is
connected to the SAT and GND on the MODGAS-
XWR (stand-alone mode) or to AI2 and GND on the
Main Controller (communicating mode).
• Remove SAT and GND wiring from MODGAS-XWR
and ohm sensor out (this may indicate open or failed
wiring). Refer to chart in back of this guide for
readings.
• Verify the SAT OPTIONS jumper settings on the
MODGAS-XWR for the Supply Air Temperature
Sensor.
SAT Cutoff Mode:
• Remove SAT and GND wiring from the MODGAS-
XWR and ohm sensor out (this may indicate open or
failed wiring). Refer to chart in back of guide for
readings.
• With Supply Air Sensor disconnected from the
MODGAS-XWR, set volt meter to DC volts and
measure voltage between SAT and GND on board.
Refer to chart in back of this guide for readings.
• Verify Supply Air Temperature Sensor reading in duct
with 3rd party temperature testing device.
Communications Loss:
• Check COMM LED on MODGAS-XWR.
• Verify 24 VAC power to all interconnected WattMaster
controllers.
• Verify E-BUS connection between the MODGAS-
XWR and associated WattMaster controllers.
• In communication mode (connected to an AAON unit
Controller with modular cable), confi rm that Main
MODGAS screens shows COMM MODE that Main
Controller’s MODGAS status screen displays
MODGAS-XWR’s Position %.
Troubleshooting Alarms