Orion System MODGAS-X - Manual (Page 14)

OPERATION MODES
MODGAS-X Field Technical Guide 14
Outputs and Operation Modes
Operation Modes
The MODGAS-X Controller can be used stand-alone or communicat-
ing with an AAON Unit Controller using a modular cable.
Stand-Alone Mode
When used in a stand-alone application, the MODGAS-X Controller
will modulate the gas valve(s) and stage any additional fi xed stages to
maintain the DISCHARGE setpoint confi gured on the MODGAS-X
Controller LCD display. The MODGAS-X Controller is activated
by a 24VAC signal to the HEAT EN input.
The following are available in Stand-Alone mode using the LCD
display on the MODGAS-X Controller:
• Status
• Supply Air Temperature Setpoint Adjustment
• Supply Air Reset Temperature Setpoint
Adjustment
• Force Mode ON/OFF
• Force Valve Position
• Force Relays
• Alarms
Communicating Mode
When the MODGAS-X Controller is connected and communicating
with an AAON Unit Controller via a modular cable, the necessary
information will be passed between the MODGAS-X and the Main
Unit Controller to properly operate in the Heating Mode.
If the communication is interrupted between the MODGAS-X
Controller and the Main Controller, both boards will show an alarm.
When communication is restored, the alarms will go away.
In this confi guration, the Supply Air Temperature Setpoint is set
using the Main Controller and the Supply Air Temperature Reset is
calculated by the Main Controller.
The following are available in communicating mode using the LCD
display on the MODGAS-X Controller:
• Status
• Force Mode ON/OFF
• Force Valve Position
• Force Relays
• Alarms
Relay #3 - Aux 1
Stage 2 Heat (Fixed or Modulating) —If confi gured for two
or more stages of heat, this relay would enable the 2nd stage of
heat if the 1st modulating valve cannot maintain the confi gured
supply air temperature setpoint. This stage and any additional
stages of heat will stage up and down as required to maintain
the Supply Air Temperature Setpoint. The Stage Up Delay de-
fault is 3 minutes. The Stage Down Delay default is 1 minute.
Relay #4 - Aux 2
Stage 3 Heat (Fixed or Modulating) —If confi gured for three or
more stages of heat, this relay would enable the 3rd stage of heat as
needed to maintain the confi gured supply air temperature setpoint.
This stage and any additional stages of heat will stage up and down
as required to maintain the Supply Air Temperature Setpoint. The
Stage Up Delay default is 3 minutes. The Stage Down Delay default
is 1 minute.
12-Relay E-BUS Expansion Module - Stand-Alone
Only
Stages 4-15 Heat (Fixed) These relays should only be used in
Stand-Alone confi guration when more than three stages of heat are
confi gured. These relays will successively stage up based on the
stage up delay to maintain the confi gured supply air temperature
setpoint. This stage and any additional stages of heat will stage
up and down as required to maintain the Supply Air Temperature
Setpoint. The Stage Up Delay default is 3 minutes. The Stage Down
Delay default is 1 minute.
Revised 9/30/14