Alarms; Figure 5: Mhgrv-X Led Locations And Descriptions - AAON MHGRV-X Field Technical Manual

Supply Air Temperature Failure
• Verify that the Supply Air Temperature Sensor is
connected to the SAT and GND on the MHGRV-X or
MODGAS Controller (Stand-Alone Mode or when
using a CAV/VAV or MUA controller) or to AI2 and
GND on the AAON unit controller (communicating
mode).
• Remove SAT and GND wiring from MHGRV-X 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
MHGRV-X for the Supply Air Temperature Sensor.

Figure 5: MHGRV-X LED Locations and Descriptions

MHGRV-X Field Technical Guide
TROUBLESHOOTING
Communications Loss
• Check COMM LED on MHGRV-X.
• Verify 24 VAC power to all interconnected AAON unit
controllers.
• Verify E-BUS connection between the MHGRV-X and
associated AAON unit controllers.
• In communication mode (connected to an AAON unit
controller with modular cable), confirm that controller's
MHGRV-X status screen displays MHGRV-X's Position
% and that Main MHG Reheat screens show COMM
MODE.

Alarms

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