Multi-stage Terminal Outputs, Thermostat System

4 MOUNTING AND WIRING

CONTINUED FROM PAGE 3

O/B/Y2*

Y1G

Compressor

Contactor

Stage 2

E/W1

Heat

Relay

Stage 1

THERMOSTAT

C* R

SYSTEM

Hot

24 VAC

120 VAC

Compressor	Fan	Heat
Contactor		Relay
	Relay
Stage 1		Stage 2

Neutral

TRANSFORMER

(Class II, Current Limited)

*O/B Switch must be in “O” position

Figure 5. Typical wiring diagram for single transformer multi-stage systems

Multi-stage Terminal Outputs

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.

THERMOSTAT TERMINALS

SYSTEM	L	C	R	W2	E/W1	(O/B)Y2*	Y1	G

Multi-Stage	Malfunction	24 Volt	24 Volt	Heat mode	Heat mode	Cool Mode	Cool mode	Blower/Fan Energized
	Light	(Common)	(Hot)	2nd stage	1st stage	2nd stage	1st stage	on call for Cool (and
								Heat if configured
								to Electric Heat)

*O/B switch must be in “O” position

Heat Pump 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

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.

THERMOSTAT TERMINALS

SYSTEML

E/W1

(O/B)Y2

Single-stage compressor system; gas or electric backup

Heat Pump 1 Malfunction Light

24 Volt	24 Volt
(Common)	(Hot)

Heat mode 2nd stage (Aux.)

Emergency

Mode

Heat

B:Energized in Heat, Off, Emergency Mode

O:Energized in Cool Mode

Heat and	Blower/Fan Energized
Cool mode	on call for Heat
1st stage	and Cool

(compressor)