Specifications

5
IF SAFETY CIRCUITS ARE IN ONLY ONE OF THE
SYSTEMS, REMOVE THE TRANSFORMER OF THE
SYSTEM WITH NO SAFETY CIRCUITS.
NOTE
Figure 5. Typical Wiring Diagram for Two Transformer Systems With NO Safety Circuits
DEPENDING ON SYSTEM
REQUIREMENTS, REPLACE
WITH A 75VA TRANS-
FORMER, IF NEEDED
TWO COMMONS MUST
BE JUMPERED TOGETHER!
CUT AND
TAPE OFF!
C
R
G
B
O
Changeover
Energized
In Heat
Changeover
Energized
In Cool
Compressor
Contactor
Stage 1
Fan
Relay
Heat
Relay
Stage 2
Heat
Relay
Stage 3
Thermostat
Control
Circuit
Compressor
Contactor
Stage 2
24vAC
120vAC
Hot
Neutral
THERMOSTAT
SYSTEM
Y1 Y2
W2
W3
E1
Emergency
Relay
Constant
Output
E2
Emergency
Relay
Switched
Output
TRANSFORMER
Malfunction
Light
System
Monitor
Switch
L
HEAT PUMP SYSTEM
AUXILIARY HEATING SYSTEM
W1
Limit or
Safety
Switches
24vAC120vAC
Hot
Neutral
TRANSFORMER
Limit or
Safety
Switches
Heat
Relay
Stage 1
NOTE
Relay contacts shown are thermostatically operated. The
accessory relay scheme is required when safety circuits
exist in both systems.
Polarity must be observed. If the HOT side of the
second transformer is jumpered to the COMMON
side of the first transformer a short will be made.
Damage to equipment will occur when power is
restored.
CAUTION
!
Figure 6. Typical Wiring Diagram for Two Transformer Systems With Safety Circuits in BOTH Systems
TWO COMMONS MUST
BE JUMPERED TOGETHER!
C R
G
B
O
Changeover
Energized
In Heat
Changeover
Energized
In Cool
Compressor
Contactor
Stage 1
Fan
Relay
Heat
Relay
Stage 2
Heat
Relay
Stage 3
Compressor
Contactor
Stage 2
24vAC
120vAC
Hot
Neutral
THERMOSTAT
SYSTEM
Y1 Y2
W2
W3
E1
Emergency
Relay
Constant
Output
E2
Emergency
Relay
Switched
Output
HEAT PUMP
TRANSFORMER
Malfunction
Light
System
Monitor
Switch
HEAT PUMP SYSTEM
AUXILIARY HEATING SYSTEM
W1
Limit or
Safety
Switches
24vAC
120vAC
Hot
Neutral
Limit or
Safety
Switches
AUXILIARY
HEATING
TRANSFORMER
Limit or
Safety
Switches
Limit or
Safety
Switches
24vAC
Accessory
Relay N.O.
Contact
Thermostat
Control
Circuit
L
Heat
Relay
Stage 1