Zone
Zone
INPUTS & OUTPUTS
18
MODGAS-XWR-1 Technical Guide
Inputs and Outputs
Table 1: MODGAS-XWR Controller Inputs & Outputs
Analog Inputs
Reset Input (RST IN)
Used only in stand-alone operation. The Supply Air Temperature Setpoint
can be reset by supplying a 0-10 VDC signal to the RST IN low voltage
terminal block. This reset signal is optional and need only be used if you
require resetting of the discharge air temperature.
Supply Air Temperature Sensor (SAT)
Used only in stand-alone operation. The Supply Air Temperature Sen-
sor is the control source. This sensor has to be installed for the unit to
operate. The Supply Air Sensor is located in the discharge air stream and
monitors temperature to maintain the Supply Air Setpoint.
Binary Inputs
Heat Enable Contact (HEAT EN)
This input is only required when the controller is used in stand-alone
operation; it is not required when used as an expansion board to other
unit controllers. The Heat Enable input is activated by a 24VAC signal
supplied from a building automation system to enable the MODGAS-
XWR Controller. The controller will not operate without 24VAC being
applied to this input terminal when used in a stand-alone confi guration.
I/O Map
The following inputs and outputs are available on the MODGAS-XWR
Controller. See
Table 1
below
to reference the Input/Output Map.
Analog Inputs
1
Reset Signal (RST IN)
2
Supply Temperature (SAT)
3
(AUX AIN) - Not Used
Binary Inputs
1
(AUX BIN) - Not Used
2
Heat Enable (HEAT EN)
3
Proof of Ignition 1 (PO-IGN1)
4
Proof of Ignition 2 (PO-IGN2)
Communicating Outputs
1
Gas Valve 1
2
Gas Valve 2
Relays
1
Fan (RLY1)
2
Low Speed Fan (RLY2)
3
Heat 1 (RLY3)
4
Heat 2 (RLY4)
5
Heat 3 (RLY5)
6
Heat 4 (RLY6)
Proof of Ignition 1 (PO-IGN1)
The Proof of Ignition input is activated by a 24VAC signal supplied
from the Ignition Module to enable the modulating Gas Valve 1 (and
the modulating Gas Valve 2 in the 2V1IGN1S confi guration). If the
fl ame does not ignite, the Ignition Module will turn off this enable.
The MODGAS-XWR Controller will then turn on the “No Proof of
Flame” alarm.
Proof of Ignition 2 (PO-IGN2)
The Proof of Ignition input is activated by a 24VAC signal supplied
from the Ignition Module to enable the modulating Gas Valve 2. If the
fl ame does not ignite, the Ignition Module will turn off this enable.
The MODGAS-XWR Controller will then turn on the “No Proof of
Flame” alarm.
Communicating Outputs
Gas Valve Output 1
This communicating output will control the modulating gas valve. It
can detect if the valve is connected and can verify the valve position.
Gas Valve Output 2
This communicating output will control the modulating gas valve. It
can detect if the valve is connected and can verify the valve position.
Relay Outputs
Relay #1 - Fan Enable
This relay works in conjunction with the Low Speed Fan Relay to
control the speed of the induced draft blower motor. When the MOD-
GAS-XWR Controller has heat enabled, this relay closes to bring the
induced draft blower on at high speed. The controller will activate the
Low Speed Fan Relay to reduce the induced draft blower speed as the
gas valve modulates closed.
Relay #2 - Low Speed Fan
Depending on the gas valve position, this relay will close to switch the
induced draft blower to low speed. The controller automatically switches
the blower to low speed as the gas valve modulates closed in order to
maintain proper fuel to air ratios.
Relay #3 - Heat 1
Once the MODGAS-XWR Controller brings on heat, Heat 1 Relay is
the fi rst stage of heat.
NOTE:
In the 2 modulating valve, 2 ignitors, 1
stage confi guration, Heat Relays #1 & #2 are one stage.
Relay #4 - Heat 2
Once the MODGAS-XWR Controller brings on heat, Heat 2 Relay is
the second stage of heat if the MODGAS-XWR is confi gured for two
stages of heat. Will either be a modulating heat stage or fi xed heat stage.
NOTE:
In the 2 modulating valve, 2 ignitors, 1 stage confi guration,
Heat Relays #1 & #2 are one stage.
Relay #5 - Heat 3
Once the MODGAS-XWR Controller brings on heat, Heat 3 Relay is
the second or third stage of heat if the MODGAS-XWR is confi gured
for three stages of heat. Will be a fi xed heat stage.
Relay #6 - Heat 4
Once the MODGAS-XWR Controller brings on heat, Heat 4 Relay is
the third or fourth stage of heat if the MODGAS-XWR is confi gured
for four stages of heat. Will be a fi xed heat stage.
