Power options
For 24VAC primary power, connect
common side of transformer to
"C" terminal.
C
C
G
G
Y
Y
O/B
W
RC
RC
R
R
CONVENTIONAL
Wiring
Remove factory-installed jumper
only for two-transformer systems.
C
G
Y
O/B
RC
R
Terminal Designations
Conventional Terminal Letters:
R
Heating power. Connect to secondary side
of heating system transformer.
Rc
Cooling power. Connect to secondary side
of cooling system transformer.
C
Common wire from secondary side of
cooling transformer (if 2 transformers).
W
1st stage heat relay.
W2 2nd stage heat relay.
Y
1st stage compressor contactor.
Y2
2nd stage compressor contactor.
G
Fan relay.
S1
Optional outdoor or remote sensor.
S2
Optional outdoor or remote sensor.
W2
Y2
NOT
USED
S1
S2
HEAT PUMP
MCR31515
SCREW
INSERT WIRES
THEN TIGHTEN SCREWS
WIRE HOLE
C
W2
G
Y2
Y
NOT
USED
W
S1
RC
S2
R
CONVENTIONAL
HEAT PUMP
AUX
E
L
S1
S2
Push excess wire back into the wall opening.
Plug wall opening with non-flammable insulation.
AUX
E
L
S1
S2
Shaded areas below apply only to TH7220.
Heat Pump Terminal Letters:
R
Heating power. Connect to secondary side
of heating system transformer.
Rc
Cooling power. Connect to secondary side
of cooling system transformer.
C
Common wire from secondary side of
cooling transformer (if 2 transformers).
Y
1st stage compressor contactor.
Aux Auxiliary heat relay.
G
Fan relay.
E
Emergency heat relay.
L
System Monitor.
O/B Changeover valve for heat pumps.
S1
Optional outdoor or remote sensor.
S2
Optional outdoor or remote sensor.
3
Insert supplied batteries for
primary or backup power.
MCR31517
TH7000 Series
M28420
69-2668ES—03