White Rodgers PART NO. 37-6509A - Manual (Page 3)

3
WIRING DIAGRAMS WIRING DIAGRAMS WIRING DIAGRAMS WIRING DIAGRAMS WIRING DIAGRAMS
L R
E/W1
SYSTEM
MONITOR
SWITCH
G W2
Figure 4. Typical wiring diagram for two transformer heat pump systems with safety circuits in BOTH systems
2nd Stage
Compressor
C Y1 Y2
Compressor
Contactor
Aux
Relay
(Stage 2)
Fan
Relay
Emergency
or 1st Aux.
Stage Relay
TWO COMMONS MUST
BE JUMPERED TOGETHER!
24 VAC 120 VAC
HOT
NEUTRAL
THERMOSTAT
SYSTEM
HOT
NEUTRAL
120 VAC
Limit or
Safety
Switches
Limit or
Safety
Switches
Limit or
Safety
Switches
24 VAC
Limit or
Safety
Switches
COMMON
COMMON
Auxiliary
Heating
Transformer
(Class II
Current Limited)
Heat Pump Transformer
(Class II Current Limited)
24 VAC
ACCESSORY
RELAY N.O.
CONTACT
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.
NOTE
The accessory relay scheme
is required when safety
circuits exist in both systems.
NOTE
Reversing
Valve
Energized in
Heat, Off,
Emergency
Mode
B
Reversing
Valve
Energized in
Cool Mode
O
C R Y2
Compressor
Contactor
Stage 1
Heat
Relay
Stage 1
Heat
Relay
Stage 2
24 VAC 120 VAC
Hot
Neutral
THERMOSTAT
SYSTEM
Y1
E/W1
W2
Figure 5. Typical wiring diagram for single transformer multi-stage systems
Fan
Relay
G
TRANSFORMER
(Class II, Current Limited)
Compressor
Contactor
Stage 2
Reversing
Valve
Energized in
Heat Mode
Off Emergency
B
Reversing
Valve
Energized in
Cool Mode
O
Refer to equipment manufacturers' instructions for specific
system wiring information.
You can configure the thermostat for use with the following
heat pump system types:
HEAT PUMP TYPE 1
HEAT PUMP TYPE 1 HEAT PUMP TYPE 1 HEAT PUMP TYPE 1 HEAT PUMP TYPE 1. Single stage compressor system; gas
or electric backup.
This thermostat is designed to operate a single-transformer
system. If you have a two-transformer system, cut and tape off
Heat Pump Terminal Outputs Heat Pump Terminal Outputs Heat Pump Terminal Outputs Heat Pump Terminal Outputs Heat Pump Terminal Outputs
one transformer. If transformer safety circuits are in only one of
the systems, remove the transformer of the system with NO
safety circuits. If required, replace remaining transformer with
a 75VA Class II transformer. After disconnecting one trans-
former, the two commons must be jumpered together.
Use the terminal output information below to help you wire the
thermostat properly for your multi-stage system. After wiring,
see CONFIGURATION
CONFIGURATION CONFIGURATION CONFIGURATION CONFIGURATION section for proper thermostat configu-
ration.
SYSTEM SYSTEM SYSTEM SYSTEM SYSTEM L L L L L C C C C C R R R R R W2 W2 W2 W2 W2 E/W1 E/W1 E/W1 E/W1 E/W1 Y2 Y2 Y2 Y2 Y2 Y1 Y1 Y1 Y1 Y1 G G G G G O O O O O B B B B B
Heat Malfunction 24 Volt 24 Volt Heat Mode Heat mode No Heat and Blower/Fan Energized Energized Energized
Pump 1 Light (Common) (Hot) 3rd stage 2nd stage Output Cool mode on call for Heat in Cool in Heat
Emergency or 1st stage and Cool Mode OFF
Heat mode Emergency 2nd (compressor) Set GAS/ELEC switch Emergency
Pump 2 2nd stage Mode stage for Emergency mode mode
1st stage compressor
THERMOSTAT TERMINALS (HEAT PUMP) THERMOSTAT TERMINALS (HEAT PUMP) THERMOSTAT TERMINALS (HEAT PUMP) THERMOSTAT TERMINALS (HEAT PUMP) THERMOSTAT TERMINALS (HEAT PUMP)