White Rodgers 1F94-80 Operating Guide
5
IF SAFETY CIRCUITS ARE IN ONLY ONE OF THE
SYSTEMS, REMOVE THE TRANSFORMER OF THE
SYSTEM WITH NO SAFETY CIRCUITS.
SYSTEMS, REMOVE THE TRANSFORMER OF THE
SYSTEM WITH NO SAFETY CIRCUITS.
NOTE
Relay contacts shown are thermostatically operated. The
accessory relay scheme is required when safety circuits
exist in both systems.
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.
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.
NOTE
CAUTION
!
Limit or
Safety
Switches
Heat
Relay
Stage 1
Figure 5. Typical wiring diagram for two-transformer system 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
Thermostat
Control
Circuit
24vAC
120vAC
Hot
Neutral
THERMOSTAT
SYSTEM
Y1
Y2
W2
E1
E2
TRANSFORMER
Malfunction
Light
System
Monitor
Switch
L
HEAT PUMP SYSTEM
AUXILIARY HEATING SYSTEM
W1
Limit or
Safety
Switches
24vAC
120vAC
Hot
Neutral
TRANSFORMER
Compressor
Contactor
Stage 1
Compressor
Contactor
Stage 2
Fan
Relay
Emergency
Relay
Switched
Output
Emergency
Relay
Constant
Output
Heat
Relay
Stage 2
A1
Damper
Motor
Limit or
Safety
Switches
Limit or
Safety
Switches
Limit or
Safety
Switches
Figure 6. Typical wiring diagram for two-transformer system 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
Compressor
Contactor
Stage 2
24vAC
120vAC
Hot
Neutral
THERMOSTAT
SYSTEM
Y1
Y2
W2
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
24vAC
120vAC
Hot
Neutral
AUXILIARY
HEATING
TRANSFORMER
Limit or
Safety
Switches
24vAC
Accessory
Relay N.O.
Relay N.O.
Contact
Thermostat
Control
Circuit
L
Heat
Relay
Stage 1
Damper
Motor
A1