Wiring Diagrams; Cool Only - Robertshaw 8625 User Manual

Wiring Diagrams

The following is just a sample of the most common types of HVAC
systems. Refer to your system's installation manual for wiring information.
HEAT/COOL
4-WIRE
SINGLE TRANSFORMER
Transformer
Hot
24 VAC
120 VAC
HEAT ONLY
2-WIRE
SINGLE TRANSFORMER
Transformer
Hot
120 VAC 24 VAC
HEAT/COOL
2 STAGE
Transformer
Hot
24 VAC
120 VAC
T
R
H
C
E
R
Heating
W1
Control
M
O
Cooling
Y1
S
Control
T
Fan
A
G
Control
T
O
B
Y2
W2/E
R
T
C
H
E
Heating
W1
Control
R
Y1
M
O
G
S
O
T
A
B
T
Y2
W2/E
R
T
H
C
E
R
L
M
First Stage
W1
O
Heat
S
First Stage
Y1
Cool
T
A
B
T
O
Fan
G
Control
Second
Y2
Stage Cool
Second
W2/E
Stage Heat
HEAT ONLY
3-WIRE
SINGLE TRANSFORMER
Transformer
Hot
24 VAC
120 VAC

COOL ONLY

3-WIRE
SINGLE TRANSFORMER
Transformer
Hot
24 VAC
120 VAC
5
R
T
H
C
E
R
Heating
W1
Control
M
O
Y1
S
T
Fan
G
Control
A
T
O
B
Y2
W2/E
R
T
C
H
E
W1
R
Cooling
M
Y1
Control
O
S
Fan
G
Control
T
O
A
B T
Y2
W2/E