Page 4 of 16 / IOM 1178-1
Installation
Figure 1: Base & rear view of thermostat
G
RC
RH
C
S
6
W1
-
+
L
Y2
Y
W4
W3
W2
D/A
Stack
Power
Stealing
Switch
Thermostat Base
Rear View of Thermostat
ON
OFF
G
RC
RH
C
S
6
W1
-
+
L
Y2
Y
W4
W3
W2
D/A
Stack
Power
Stealing
Switch
Thermostat Base
Rear View of Thermostat
ON
OFF
Mounting holes
Place level across mounting tabs
(for appearance only)
"AA" batteries (2)
Power stealing switches
Wiring
Table 4: Thermostat wiring terminals & systems operation
Thermostat Terminal
System
HP1 Operation
HP2 Operation
RC
24V power for cooling
24V power for cooling
RH
24V power for heating
24V power for heating
C
24V common
24V common
Y
Compressor cool 1st stage
Compressor cool 1st stage
Y2
No output
Compressor cool 2nd stage
W1
Compressor heat 1st stage
Compressor heat 1st stage
W2
No output
Compressor heat 2nd stage
W3
Auxiliary heat 1st stage (heat 2nd stage)
Auxiliary heat 1st stage (heat 3rd stage)
W4
Heat 2nd stage (heat 3rd stage)
Heat 2nd stage (heat 4th stage)
G
Fan
Fan
DMA/A1
Dehumidification or waterside economizer, configurable terminal
configuration menu
Dehumidification or waterside economizer, configurable terminal
configuration menu
6
Powered close connection for SPDT 3-wire zone valve
Powered close connection for SPDT 3-wire zone valve
L
System diagnostic indicator
System diagnostic indicator
