Emerson 1F73 - Manual (Page 4)

MOUNTING AND WIRING
CONTINUED FROM PAGE 3
4
C* R
O/B/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)
*O/B Switch must be in “O” position
Compressor
Contactor
Stage 2
Refer to equipment manufacturers’ instructions for specific sys-
tem wiring information.
You can configure the thermostat for use with either multi-stage
electric heat systems or multi-stage gas systems. When config-
ured for electric heat, the G terminal (blower/fan) will be ener-
gized on a call for heat.
This thermostat is designed to operate a single-transformer
system. If you have a two-transformer system, cut and tape of 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 transformer, 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 section for proper thermostat configuration.
Multi-stage Terminal Outputs
Refer to equipment manufacturers’ instructions for specific sys-
tem wiring informtion.
You can configure the thermostat for use with the following heat
pump system types:
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 of one
Heat Pump Terminal Outputs
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 transformer, 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 section for proper thermostat configuration.
SYSTEM L C R W2 E/W1 (O/B)Y2* Y1 G
Malfunction
Light
Multi-Stage
*O/B switch must be in “O” position
24 Volt
(Common)
24 Volt
(Hot)
Heat mode
2nd stage
Heat mode
1st stage
Cool Mode
2nd stage
Cool mode
1st stage
Blower/Fan Energized
on call for Cool (and
Heat if configured
to Electric Heat)
THERMOSTAT TERMINALS
SYSTEM L C R W2 E/W1 (O/B)Y2 Y1 G
Single-stage compressor system; gas or electric backup
Malfunction
Light
Heat Pump 1 24 Volt
(Common)
24 Volt
(Hot)
Heat mode
2nd stage
(Aux.)
Emergency
Mode
Heat
B: Energized in Heat, Off,
Emergency Mode
O: Energized in Cool Mode
Heat and
Cool mode
1st stage
(compressor)
Blower/Fan Energized
on call for Heat
and Cool
THERMOSTAT TERMINALS
www.white-rodgers.com