Terminal Designations; Wiring Configurations - Honeywell Round Guía De Instalación Profesional

Wiring

Terminal Designations

L
Heat pump system monitor
C
Common wire from secondary side of
cooling transformer, if 2 transformers
W2 2nd stage heat relay (heat pump
(AUX) auxiliary, emergency heat)
W 1st stage heat relay (changeover valve
(O/B)
for heat pumps)
U1
Universal terminal for indoor air quality
products (humidifier, dehumidifier,
ventilator)
U2
Universal terminal for indoor air quality
products (humidifier, dehumidifier,
ventilator)

Wiring Configurations

Two stage furnace and air-conditioning
C Common wire (optional)
W2
Heat relay (stage 2)
W Heat relay
G
Fan relay
Y2 Compressor contactor (stage 2)
Y
Compressor contactor (stage 1)
R Power
8
K
Optional wire saver module
G
Fan relay
Y2 2nd stage compressor contactor
Y 1st stage compressor contactor
R
Heating power. Connect to
secondary side of heating
system transformer
Rc
Cooling power. Connect to
secondary side of cooling
system transformer
Notes
• Thermostat C wire
is optional for this
application. C wire
required if Homekit
is used.
• Set the R Jumper
Switch on the wall
plate to R