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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
W
W Heat relay.
Y
Y Compressor contactor.
G
G Fan relay.
O
O Heat pump changeover valve
energized in cooling.
R
Rc
c Cooling power. Connect to
secondary side of cooling
system transformer.
R
R Heating power. Connect to
secondary side of heating
system transformer.
B
B
Heat pump changeover valve
energized in heating.
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
.
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
Содержание PRO TH4110B
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