VCB-X Controller Field Technical Guide
INSTALLATION & WIRING
53
MODGAS-X Controller Wiring
MODGAS-X Controller Wiring
The OE377-26-00058 MODGAS-X Controller (AAON Part No.
V12090) is designed to modulate up to (2) gas valves to maintain
a desired Discharge Air Temperature. It also controls the speed of
the induced draft fan to maintain proper combustion in the heat
exchanger.
The MODGAS-X Controller directly connects to the VCB-
X Controller or indirectly using an E-BUS Expansion Board via an
EBC E-BUS cable. See
Figure 39
.
The following information will be passed between the MODGAS-X
controller and the VCB-X Controller:
Heat activation command
Heating Discharge Setpoint
The offset for the Supply Air Temperature Sensor
High Limit Temperature Setpoint
If the communication is interrupted between the
MODGAS-X Controller and the VCB-X Controller,
the MODGAS-X controller will revert to stand-alone
operation.
For more information, refer to the
MODGAS-X Controller Technical
Guide.
NOTE:
If using multiple E-BUS Sensors or Modules, the
E-BUS Hub or Adapter Board may be required.
Figure 39: MODGAS-X Controller to VCB-X Controller Wiring Diagram
MODGAS-X CONTROLLER
(OE377-26-00058)
Supply
Air Temperature
Sensor
Mount In Supply
Air Duct
Connect
to AI2 & GND
On VCB-X Controller
Supply Air Temperature
Sensor
EBC E-BUS Cable
Connects To
VCB-X Controller’s
Expansion
Port
Set Jumper To 1.
Fan Enable
Low Speed Fan
24 VAC Power
Input Terminals
Max. Power
Consumption
1 Gas Valve
= 18 VA
2 Gas Valves
= 33 VA
Aux Heat Valve
Revised 8/29/13
