18
MODGAS-XWR2 Technical Guide
COMMUNICATIONS WIRING
Secondary Board - 2V2IGN2S
Figure 12: Communications Wiring - Secondary Board 2V2IGN2S
Fan Enable
Low Speed Fan
Modulating
Gas Valve 3
(Slave to Mod
Gas Valve 1)
Proof of Ignition
Signal 3 (24 VAC)
Heat Valve 1
Check your Fan Relay Wiring (RLY1)
Schematic for proper wiring.
Heat Valve 2
Fixed Heat Stage 5
Fixed Heat Stage 6
ALARM
UP
DOWN
ENTERMENU
MODGAS-XWR2
AAON P/N:ASM01695
LABEL P/N:
G041530
E-BUS
DUAL
I2C
CONNECT
+24 VAC
GND
@ 24 VAC
1 AMP MAX
CONTACT
RATING IS
COMMON
RELAY
OUTPUTS
GAS VALVE
TERMINALS
GAS
VALVE 1
GAS
VALVE 2
INPUT TERMINALS (TYPE)
HEAT ENABLE (BI)
AUX. (BI)
GND
RESET IN (AI)
SAT IN (AI)
GND (AI)
GND
AUX. (AI)
www.aaon.com
LOW SPEED
HEAT 1
HEAT 2
HEAT 3
HEAT 4
PROOF OF IGNITION 1
PROOF OF IGNITION 2
FAN
Notes:
1. 24 VAC must be connected so that all ground wires
remain common.
2. All wiring to be in accordance with local and national
electrical codes and specifications.
E-BUS cable connects to the
primary MODGAS-XWR2.
GV3
CR3
CR4
H1
Line
40 VA
transformer
minimum
GND
18-30
VAC
H2
Proof of Ignition
Signal 4 (24 VAC)
GV4
Modulating
Gas Valve 4
(Slave to Mod
Gas Valve 2)
In this conguration, the wiring on Figure 11, page 17 is the
primary portion and Figure 12, this page is the secondary
portion, thus creating four modulating valves as two stages.
NOTE: This conguration is not supported when using
I
2
C communications.
NOTE: Up to two additional xed heat stages can be
congured by using Heat 3 (RLY5) and Heat 4
(RLY6). If additional xed stages are required,
these should be configured and wired to the
AAON unit controller’s relays.