Installation guide

VisionPRO
®
TH8110 / TH8320 / TH8321
3
Wiring
Insert supplied batteries for
primary or backup power.
For 24VAC primary power, connect common
side of transformer to “C” terminal.
Power options
Terminal Designations Shaded areas below apply only to TH8320/TH8321
Remove factory-installed jumper
only
for two-transformer systems.
Push excess wire back into the wall opening. Plug
wall opening with non-flammable insulation.
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.
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 system transformer.
Y 1st stage compressor contactor.
Y2 2nd stage compressor contactor.
Aux Auxiliary heat relay.
G Fan relay.
E Emergency heat relay.
L Heat pump reset (powered continuously
when System is set to Em Heat; system
monitor when set to Heat, Cool or Off).
O/B Changeover valve for heat pumps.
S1 Optional outdoor or remote sensor.
S2 Optional outdoor or remote sensor.