Service manual

ACCESSORIES WIRING DIAGRAMS
49
TO AVOID POSSIBLE ELECTRICAL SHOCK, PERSONAL INJURY,
OR DEATH, DISCONNECT THE POWER BEFORE SERVICING.
WARNING
!
EMERGENCY
HEAT
RELAY
13 42
BLUE
WHITE
BLACK
BROWN
THERMOSTAT
OT/EHR18-60
21
From Air Handler
CGW2 R
CRW2OY
From Outdoor Unit
C
G
W2
E
R
O
Y
Indoor Thermostat
BL
U
E
GREE
N
WHITE
RED
B
L
UE
RED
WH
IT
E
OR
A
N
GE
YEL
L
OW
10kw and Below, One Stage Electric Heat
RED
EMERGENCY
HEAT
RELAY
1 42
BLUE
WHITE
BLACK
BROWN
THERMOSTAT
OT/EHR18-60
21
From Air Handler
CGW2 R
CRW2OY
From Outdoor Unit
C
G
W2
E
R
O
Y
Indoor Thermostat
W3
B
L
U
E
G
R
E
E
N
W
H
I
T
E
RED
BROWN
BLUE
R
ED
WH
IT
E
O
R
A
N
GE
YE
L
LOW
15kw and Above, Two Stage Electric Heat
3
RED
SEE NOTE
Note:
When using a Thermostat with only one
stage for electric heat (W2), tie white and
brown wires from air handler together.
Typical Wiring Schematics for OT/EHR18-60 (Outdoor Thermostat & Emergency Heat Relay).
This wiring diagram is for reference only. Not all wiring is as shown above.
Refer to the appropriate wiring diagram for the unit being serviced.