Fantech SHR Serie Manuel D'installation page 19

Electrical connections (Cont'd)
ELECTRICAL
CONNECTION TO
FURNACE
FOR A FURNACE
CONNECTION TO
A COOLING SYSTEM:
On some older thermostats, energizing
the R and G terminals at the furnace
has the effect of energizing Y 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".
Never connect a 120 volt AC circuit to the terminals of the Accessory Control Contacts. Only use
the low voltage class 2 circuit of the furnace blower control.
Standard Accessory Control Contact
Standard Furnace Interlock Wiring
W
FOUR
WIRE
TWO WIRE
heating only
W
R
G
C
Y
FURNACE
24-VOLT
TERMINAL BLOCK
Alternative Accessory Control Contact
Alternate Furnace Interlock Wiring
W
FOUR
WIRE
TWO WIRE
heating only
W
R
WIRE JOINT
G
C
Y
FURNACE
24-VOLT
TERMINAL BLOCK
THERMOSTAT
TERMINALS
R G Y
TWO
WIRE
THERMOSTAT
TERMINALS
R G
Y
TWO
WIRE
19
COOLING SYSTEM
COOLING SYSTEM