Thermostat 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
Figure 27: Two-Stage Piping
OUT
IN From Water Source
NOTE: Shut-off valves, strainers and
other required components not shown.
CAUTION! Many units installed with a factory or fi eld
supplied manual or electric shut-off valve. DAMAGE WILL
OCCUR if shut-off valve is closed during unit operation. A
high pressure switch must be installed on the heat pump
side of any fi eld provided shut-off valves and connected to
the heat pump controls in series with the built-in refrigerant
circuit high pressure switch to disable compressor operation
if water pressure exceeds pressure switch setting. The fi eld
installed high pressure switch shall have a cut-out pressure
of 300 psig and a cut-in pressure of 250 psig. This pressure
switch can be ordered from Carrier Geothermal with a 1/4"
internal fl are connection as part number 39B0005N02.
ELECTRICAL - THERMOSTAT WIRING
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 and 28b 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.
32
Solenoid
Flow
Valve
Regulator
Stage 2
To Discharge
Stage 1
CAUTION!
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
CAUTION!
CAUTION! Refrigerant pressure activated water regulating
valves should never be used with Carrier Geothermal
equipment.
Figure 28b: Typical Thermostat Wiring, Single-Stage
Units (2 Heat/1 Cool)
CXM Board Typical
(Compressor Air Handler
Section)
Y Y/Y2
O O
G G
R R
C C
W1
Optional
Jumper
W2
AL1
Figure 28a: Typical Thermostat Wiring, Two-Stage Units
(3 Heat/2 Cool)
From Compressor
Solenoid Valve
CXM Board
(Compressor Air Handler
Section)
Y/Y2
Y
O
G
R
C
W1
W2
AL1
Typical
T-stat
Y
O
G
R
C
W
E
L
Typical Typical
T-stat
Y2
Y1
Y1
O O
G G
R R
C
C
W
E
L