Loading ...
Loading ...
Loading ...
5. ELECTRICAL CONNECTION TO THE FURNACE
15
For a furnace connected to a cooling system:
On some older thermostat, energizing the “R” and “G” terminals at the furnace has the effect of energizing “Y” terminal at the thermostat
and thereby turning on the cooling system. If you identify this type of thermostat, you must use the ALTERNATE FURNACE INTERLOCK WIRING.
WARNING
Never connect a 120-volt AC circuit to the terminals of the furnace interlock (standard wiring). Use only the low
voltage class 2 circuit of the furnace blower control.
!
W R G
Y
W
R
G
C
Y
UNIT TERMINAL CONNECTOR
THERMOSTAT
TERMINALS
FOUR
WIRES
TWO WIRES
heating only
FURNACE
24-VOLT
TERMINAL BLOCK
TWO WIRES
COOLING SYSTEM
NO C NC I OC OL Y R G B
W R G Y
W
R
Y
R
G
Y
C
THERMOSTAT
TERMINAL
4 WIRES
2 WIRES
heating only
wiring
nuts
FURNACE
24-VOLT
TERMINAL BLOCK
2 WIRES
COOLING SYSTEM
NO
NC
C
UNIT TERMINAL CONNECTOR
NO C NC I OC OL Y R G B
VE0108A
STANDARD FURNACE INTERLOCK WIRING ALTERNATE FURNACE INTERLOCK WIRING
Loading ...
Loading ...
Loading ...