Carrier GT-G, GT-S, GT-PX Typical Thermostat Wiring, Two-Stage Units 3 Heat / 2 Cool

Thermostat Wiring

Indoor & Outdoor Split Geothermal Comfort Systems

Thermostat Installation

The thermostat should be located on an interior wall in a larger room, away from supply duct drafts. DO NOT locate the thermostat in areas subject to sunlight, drafts or on external walls. The wire access hole behind the thermostat may in certain cases need to be sealed to prevent erroneous temperature measurement. Position the thermostat back plate against the wall so that it appears level and so the thermostat wires protrude through the middle of the back plate. Mark the position of the back plate mounting holes and drill holes with a 3/16” (5mm) bit. Install supplied anchors and secure plate to the wall. Thermostat wire must be 18 AWG wire. Wire the appropriate thermostat as shown in Figures 28a through 28c to the low voltage terminal strip on the CXM control board. Practically any heat pump thermostat will work with these units, provided it has the correct number of heating and cooling stages.

Typical Thermostat Wiring, Two-Stage Units (3 Heat / 2 Cool)

From Compressor

Solenoid Valve

CXM Board	FV4	TSTAT CCPRH01
(Compressor	Air Handler	or BBPRH01
Section)	Y/Y2	Y/Y2
Y	Y1	Y1/W2
O	O	O/W2
	G	G
R	R	R
	Remove Jumper
	for Dehum Mode

Typical Thermostat Wiring, Single-Stage Units (2 Heat / 1 Cool)

From Compressor

Solenoid Valve

CXM Board	FV4	TSTAT CCPRH01
(Compressor	Air Handler	or BBPRH01
Section)	Y/Y2	Y/Y2
Y	Y1	Y1/W2
O	O	O/W2
	G	G
R	R	R
	Remove Jumper
	for Dehum Mode
C	DH	DHum
	W1	W/W1
	W2
	C	C
	Humidifier	Hum
	Sol. Vlv. 24VAC
	Outdoor	S1
	Sensor
		S2

Notes:

1.Thermostat DIP switches must be configured for two-speed heat pump.

2.Compressor 2nd stage connection is not part of the terminal strip on the CXM board. A wire nut connection is required between the compressor solenoid valve and Y/Y2 connection at the fan coil.

Typical Thermostat Wiring,

Infinity / Evolution Controls

C	DH	DHum
	W1	W/W1
	W2
	C	C
	Humidifier	Hum
	Sol. Vlv. 24VAC
	Outdoor	S1
	Sensor
		S2

Notes:

1.Thermostat DIP switches must be configured for two-speed heat pump.

2.Compressor 2nd stage connection is not part of the terminal strip on the CXM board. A wire nut connection is required between the compressor solenoid valve and Y/Y2 connection at the fan coil.

From Compressor

Solenoid Valve

(Notes 1,2)

CXM Board (Compressor Section)

Y

O

C

R

Network

Interface Module

Y2

Y1

O

C

FE4 or Other

RCommunicating

Indoor Unit

AA

B B

C C

DD

User

Interface

A

B

C

D

Notes:

1.Compressor 2nd stage connection is not part of the terminal strip on the CXM board. A wire nut connection is required between the compressor solenoid valve and N.I.M.

2.Y2 connection on N.I.M. is not used for single stage units.

Carrier Indoor & Outdoor Split Geothermal Heat Pumps - Rev.: 08/10/05

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