Wiring Diagrams - Robertshaw 8425 User Manual

110-1090.qxd 7/22/04

Wiring Diagrams

♦
HEAT/COOL
4-WIRE
SINGLE TRANSFORMER
Transformer
Hot
120 VAC 24 VAC
Heating
Control
Cooling
Control
Fan
Control
HEAT ONLY
2-WIRE
SINGLE TRANSFORMER
Transformer
Hot
120 VAC 24 VAC
Heating
Control
HEAT/COOL
2 STAGE
Transformer
Hot
120 VAC 24 VAC
First Stage
Heat
First Stage
Cool
Fan
Control
Second
Stage Cool
Second
Stage Heat
8:39 AM Page 5
HEAT ONLY
SINGLE TRANSFORMER
T
R
Transformer
H
Hot
C
E
24 VAC
120 VAC
R
W1
M
O
Y1
S
T
A
G
T
O
B
Y2
W2/E
COOL ONLY
SINGLE TRANSFORMER
R
Transformer
T
C
Hot
H
24 VAC
120 VAC
E
W1
R
Y1
M
O
G
S
O
T
A
B
T
Y2
W2/E
R T
H
C
E
R
L
M
W1
O
S
Y1
T
A
B
T
O
G
Y2
W2/E
5
3-WIRE
R
T
H
C
E
R
Heating
W1
Control
M
O
Y1
S
T
Fan
G
Control A
O T
B
Y2
W2/E
3-WIRE
R
T
C
H
E
W1
R
Cooling
M
Y1
Control
O
S
Fan
G
Control
T
O
A
B T
Y2
W2/E