12
MODGAS-X Technical Guide
WIRING
Two Modulating Valves and up to 13 Stages of Fixed Heat Stand-Alone
Fan Enable And
Stage 1 Heat (Mod)
Low Speed Fan
See
for jumper settings.
Only one Supply Air Temperature Sensor
can be used per application.
SAT OPTIONS Table
Note:
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.
Connect SAT and GND Input to
Reheat board’s SAT Input if
applicable.
0-10 VDC
External Reset
Signal
-
+
Heat Enable
Signal (24 VAC)
W1
Supply Air
Temperature
Sensor
Mount in unit
supply air duct.
GV1
CR1
H1
CR2
MODGAS-X
AAON P/N: ASM01668
LABEL P/N:
G041210
E-BUS
CONNECT
I2C
CONNECT
+24
V
A
C
GND
CONTACT RATING
@ 24 VAC
IS 1 AMP MAX
VOUT
GND
GAS VALVE
TERMINALS
COMM
RELAY OUTPUT
TERMINALS
INPUT TERMINALS (TYPE)
HEAT EN (BI)
AUX. (BI)
GND
RESET IN (AI)
SAT IN (AI)
GND (AI)
GND
AUX. (AI)
AUX 1
LOW SPEED
FAN
AUX 2
H2
Stage 2 Heat (Mod)
H3
Stage 3 Heat (Fixed)
40 VA
transformer
minimum
18-30 VAC
GND
Line
E-BUS cable connects to
12 Relay E-BUS expansion port
GV2
24 VAC power input terminals
maximum power consumption
One Gas Valve = 18 VA
Two Gas Valves = 33 VA
YS102378 REV 1
Two Modulating Valves with up to 13
Additional Stages of Fixed Heat
Stand-Alone Wiring
This configuration only applies to Stand-Alone Mode
(
Figure 6, this page
) and is factory-configured.
In this configuration, the first Modulating Valve is enabled by the
FAN Relay (RLY1). The second Modulating Valve is enabled by
the AUX1 Relay (RLY3). The fixed stage uses the AUX2 (RLY4)
relay to enable it (
Figure 6, this page
). Additional fixed stages
can be added by using the 12 Relay E-BUS Expansion Module.
(
Figure 7, page 13
).
If using a MHGRV-X Module along with the MODGAS-X
in Stand-Alone, the SAT Sensor always connects to the
MODGAS-X.
This configuration can use either the MAXITROL
®
0-20 volt
valve(s) or the MAXITROL
®
EXA STAR 0-10 volt stepper
valve(s) (configured at the factory). See
Appendix C, page 36
for depiction.
WARNING:
Do not connect power to VOUT/Ground
terminal block.
If communication is lost to the 12 Relay E-BUS Expansion
Module, it will turn off its relays and the MODGAS-X will alarm
and fall back to using only its onboard stages. If communications
is restored, the MODGAS-X will begin staging up if needed.
Figure 6: Two Modulating Valves - Stand-Alone
