Filter
Top Products
Installation Guide
4
Wiring
1 Loosen screw terminals, insert
wires into terminal block, then re-
tighten screws.
2 Push excess wire back into the
wall opening. Keep wires in shaded
area as shown at left.
3 Plug the wall opening with non-
flammable insulation to prevent
drafts from affecting thermostat
operation.
Terminal Designations
WW
Heat relay.
YY
Compressor contactor.
GG
Fan relay.
OO
Heat pump changeover valve ener-
gized in cooling.
RRcc
Cooling power. Connect to
secondary side of cooling
system transformer.
RR
Heating power. Connect to
secondary side of heating
system transformer.
BB
Heat pump changeover valve ener-
gized in heating.
CC
Common wire from secondary side
of cooling system transformer.
Terminal
block
NOTES
R & Rc terminals
In single-transformer system, leave metal
jumper in place between R & Rc. Remove
metal jumper if two-transformer system
.
Heat pump systems
If wiring to a heat pump, use a small piece of
wire (not supplied) to connect terminals W
and Y.
C terminal
The C (common wire) terminal is optional
when thermostat is powered by batteries.
Wire specifications
Use 18- to 22-gauge thermostat wire.
Shielded cable is not required.
Keep wires in this
shaded area
CAUTION: ELECTRICAL HAZARD. Can cause electrical shock or equipment damage.
Disconnect power before wiring.
Wiring
Jumper