Instruction manual

PROCEDURE 8—OPERATING AND INSTALLING CHARACTERISTICS
A. PCB Component Layout, Description, and Function
1. Low-voltage terminal board is used to connect indoor thermostat to 24-v secondary side of transformer, and to serve as a junction between
indoor thermostat and outdoor unit. (See Fig. 2.)
a. R is used to connect secondary side of transformer to thermostat and outdoor unit. R is fused.
b. C is used to connect transformer secondary common for thermostat and outdoor unit.
c. Y is input signal from thermostat signaling heat pump operation.
d. G is input signal from thermostat, signaling continuous fan operation.
e. O is input and junction terminal for reversing valve signal.
f. W2D is input from outdoor unit (heat pump), signaling control board that heat pump is in defrost.
Fig. 8—System Wiring Diagram Using A Corporate Model Heat Pump Indoor Thermostat, With Supplemental Heat Relay
A97219
R
C
Y
G
O
W2D
W2T
W3
Y
0
R
C
O
W2
Y
INDOOR
CONTROL
BOARD
OUTDOOR
SPLICE
SHR ODT
SHR
CUT
JW1
R
C
Y/Y2
G
O/W2
W/W1
24 VAC HOT
24 VAC COMM
COOL / HEAT
STAGE 1
FAN
RVS COOLING
HEAT STAGE 2
MODEL HP
THERMOSTAT
SINGLE-SPEED HEAT
PUMP DEFROST BOARD
Fig. 7—System Wiring Diagram Using A Typical Indoor Heat Pump Thermostat, With Supplemental Heat Relay
A94130
R
C
Y
G
O
W2D
W2T
W3
Y
0
R
C
Y
G
O
E
W2
L
R
C
O
W2
Y
L
TYPICAL
HEAT PUMP
THERMOSTAT
INDOOR
CONTROL
BOARD
OUTDOOR
SPLICE
ODT
SHR
SHR
CUT
JW1
SINGLE-SPEED
HEAT PUMP
DEFROST BOARD
—8—