WIRING
5
Terminal Designations
Terminal
2 Heat, 2 Cool
Configuration
3 Heat, 2 Cool
Configuration
R
C
B
O
G
Transformer power
Transformer common
Heat pump changeover
valve energized in heating
Heat pump changeover
valve energized in cooling
Fan relay
Transformer power
Transformer common
Heat pump changeover
valve energized in heating
Heat pump changeover
valve energized in cooling
Fan relay
Terminal
2 Heat, 2 Cool
Configuration
3 Heat, 2 Cool
Configuration
E
Y1
Y2
W2
L
Emergency heat relay
First stage of heat & cool
Second stage of cool
Auxiliary heat relay,
second stage of heat
Malfunctioning light
Emergency heat relay
First stage of heat & cool
Second stage of cool &
second stage of heat
Auxiliary heat relay,
third stage of heat
Malfunctioning light
This thermostat is shipped from the factory to operate a 2 heat, 2 cool heat pump system. This thermostat will also
operate a 3 heat, 2 cool heat pump system if the first and second stage of heating is from the compressor(s).
See the “stages of heat” configuration step on page 8 of this manual to configure the thermostat for 3 heat applications.
Warning:
All components of the control
system and the thermostat
installation must conform to
Class II circuits per the NEC Code.
Note:
In many systems with no emergency heat relay
a jumper can be installed between E and W2.
L Terminal:
If the "L" terminal is used then the "C" terminal
must be connected.
Wiring
If you are replacing a thermostat, make
note of the terminal connections on the
thermostat that is being replaced. In some
cases the wiring connections will not be
color coded. For example, the green wire
may not be connected to the
G terminal.
Loosen the terminal block screws. Insert
wires then retighten terminal block screws.
Place nonflammable insulation into wall
opening to prevent drafts.
1.
2.
3.
