AccuAir AS7812 Installation, Operation & Application Manual page 10

4-Wire, Single Transformer
Transformer
HOT
120 VAC 24 VAC

Heating Only
R
T
C
H
E
Heating
W
R
Control
M
Y
O
S
B
T
A
O
T
Fan
G
Control
3-Wire, Single Transformer
Transformer
HOT
120 VAC 24 VAC
R
T
C
H
E
Heating
W
R
Control
M
Y
O
S
B
T
A
O
T
G