AAON MHGRVX-A2 Technical Guide

34MHGRVX-A2 Module Technical Guide
Q: Are the communications wired and congured correctly?
A: For the MHGRVX-A2 operating as Stand-Alone, the
following should be true:
1. The MHGRVX-A2 is connected to the Reheat Expansion
Module with an E-BUS cable and the connections are
secure.
2. The MHGRVX-A2 must be congured as S/A LOCKED
in the MHGRVX-A2 Conguration Screens. To conrm
this, press the ENTER key once from the main screen.
It should display S/A MODE LOCKED.
3. The MHGRVX-A2 must be congured for EXP VLVS
ENABLED in the MHGRVX-A2 Conguration Screens.
If this is true, the COMM LED on the MHGRVX-A2
will blink once every second.
A: For the MHGRVX-A2 operating with a VCCX2/VCB-X, the
following should be true:
1. The VCCX2 or VCB-X, MHGRVX-A2, and Reheat
Expansion Module are connected to each other with an
E-BUS cable and the connections are secure.
2. The MHGRVX-A2 must be configured as S/A
AUTODECT in the MHGRVX-A2 Configuration
Screens. To conrm this, press the ENTER key once
from the main screen. It should display COMM MODE.
3. The MHGRVX-A2 must be congured for EXP VLVS
ENABLED in the MHGRVX-A2 Conguration Screens.
If this is true, the COMM LED on the MHGRVX-A2
will blink once every second.
Q: How do I change congurations for the valve expansion
modules?
A: Congurations will always match how the MHGRVX-A2 is
congured. The congurations are as follows:
1. Valve Size (hidden screen conguration)
2. Cooling Flush Time (setpoint screens when Stand-
Alone)
3. Reheat Flush Time (setpoint screens when Stand-Alone)
4. Reheat Flush Reset Position (cannot be changed by user)
APPENDIX D: FREQUENTLY ASKED QUESTIONS
Troubleshooting

AAON MHGRVX-A2 Specifications

General

Brand	AAON
Model	MHGRVX-A2
Category	Control Unit
Language	English