Installation Instructions

2
MCR29436
Power options
Wiring terminal designations
Shaded areas below apply only to TH6320U/TH6220D or as otherwise noted.
Keep wires in this
shaded
area
Connect C for primary AC power
(optional if batteries are installed).
Insert batteries for primary
or backup power.
Remove factory-
installed jumper
only for two-
transformer
systems.
Conventional Terminals:
Rc 24VAC power from cooling
transformer
R 24VAC power from heating
transformer
W Heat relay (stage 1)
W2 Heat relay (stage 2)
Y Compressor contactor (stage 1)
Y2 Compressor contactor (stage 2)
G Fan relay
C 24VAC common. For 2 transformer
systems, use common wire from
cooling transformer.
Heat Pump Terminals:
Rc 24VAC power from cooling
transformer
R 24VAC power from heating
transformer
O/B Changeover valve
Y Compressor contactor
Y2 Compressor contactor (stage 2)
-TH6320U only
G Fan relay
Aux/E Auxiliary/Emergency heat relay
L Sends output when set to Em. Heat
C 24VAC common
TH6110D
RcYWGRC
TH6220D
RcYWGW2Y2 RC
TH6320U
RcYWGW2Y2 RC
MCR29437A
TH6110D
RcYGRC
RcY
G
LR
C
TH6220D
RcYGAux
E
Y2
LR
C
TH6320U
MCR29438A
Aux
E