Electrical - Low Voltage Wiring - Carrier GT-PX Split Series Installation, Operation & Maintenance Instructions Manual

R e s i d e n t i a l S p l i t - 6 0 H z R 2 2 & R 4 1 0 A
R e v. : 5 J u n e , 2 0 0 8

Electrical - Low Voltage Wiring

Thermostat Connections
The thermostat should be wired directly to the CXM board.
Figures 22a through 22c show low voltage wiring. Note that
the air handler or furnace transformer will be used to power
the CXM board in the compressor section. See "Electrical –
Thermostat" for specifi c terminal connections.
Figure 22a: 50YDS Low Voltage Field Wiring
Low voltage
fi eld wiring
Figure 22b: GT-GS Low Voltage Field Wiring
Contactor -CC
30
ELECTRICAL - LOW VOLTAGE WIRING
Capacitor
Circ Brkr
Loop PB1 HWG PB2
Grnd
L1
L2
BR
CXM Control
Low Voltage
Connector
W a t e r- S o u r c e H e a t i n g a n d C o o l i n g S y s t e m s
Figure 22c: GT-S Low Voltage Field Wiring
FCR
T2 T1
CC
Grnd
L2 L1
CRC
Low Water Temperature Cutout Selection
The CXM control allows the fi eld selection of low water (or
water-antifreeze solution) temperature limit by clipping jumper
JW3, which changes the sensing temperature associated with
thermistor FP1. Note that the FP1 thermistor is located on
the refrigerant line between the coaxial heat exchanger and
expansion device (TXV). Therefore, FP1 is sensing refrigerant
temperature, not water temperature, which is a better indication
of how water fl ow rate/temperature is affecting the refrigeration
circuit.
The factory setting for FP1 is for systems using water (30°F
[-1.1°C] refrigerant temperature). In low water temperature
(extended range) applications with antifreeze (most ground
loops), jumper JW3 should be clipped as shown in Figure
23 to change the setting to 10°F [-12.2°C] refrigerant
temperature, a more suitable temperature when using
an antifreeze solution. All residential units include water/
refrigerant circuit insulation to prevent internal condensation,
which is required when operating with entering water
temperatures below 59°F [15°C].
CXM Control
Low Voltage
Connector
Thermostat Connection
See Thermostat section
for Wiring Details