C L I M A T E M A S T E R W A T E R - S O U R C E H E A T P U M P S
Tranquility
®
Compact Belt Drive (TCH/V) Series
Rev.: July 25, 2017
42
C l i m a t e M a s t e r Wa t e r - S o u rc e H e a t P u m p s
Electrical - Power & Low Voltage Wiring
ELECTRICAL - LOW VOLTAGE WIRING
Figure 16: TCH 072-120 Low Voltage Field Wiring
(CXM Shown) NOTE: For DXM, Y2 wiring at DXM1
Thermostat Connections
- The thermostat should be
wired directly to the CXM or DXM board. Figure 16
shows wiring for TC units. See “Electrical – Thermostat”
(Figure 20) for specifi c terminal connections. Review the
appropriate AOM (Application, Operation and Mainte-
nance) manual for units with DDC controls.
Low Water Temperature Cutout Selection
- The CXM/
DXM 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 LT1. Note that the LT1
thermistor is located on the refrigerant line between the
coaxial heat exchanger and expansion device (TXV or cap
tube). Therefore, LT1 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 LT1 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 17 to change the setting to
10°F [-12.2°C] refrigerant temperature, a more suitable
temperature when using an antifreeze solution. All
ClimateMaster units operating with entering water
temperatures below 59°F [15°C] must include the
optional water/refrigerant circuit insulation package to
prevent internal condensation.
CXM1 Low
Voltage
Connector
CXM2
Figure 17: LT1 Limit Setting
CXM PCB
LT1
LT2
JW3-LT1 jumper
should be clipped
for low temperature
operation
Figure 18 : Accessory Wiring
Low Voltage VA Ratings
Components In Unit
VA
Typical Blower Contactor
6 - 9
Typical Reversing Valve Solenoid (2)
8 - 12
30A Compressor Contactor (2)
12 - 18
CXM board (2)
10 - 18
DXM board (2)
16 - 24
Units with CXM
Remaing VA for Accessories
39 - 18
Units with DXM
Remaing VA for Accessories
33 - 12
Standard transformer is 75VA.
Accessory Connections
- A terminal paralleling the
compressor contactor coil has been provided on
the CXM/DXM control. Terminal “A” is designed to
control accessory devices, such as water valves. Note:
This terminal should be used only with 24 Volt signals
and not line voltage. Terminal “A” is energized with
the compressor contactor. See the specifi c unit wiring
diagram for details.
Models with Waterside Economizer
- Controller is
factory assembled. Factory settings are 45°F (7.2°C), valve
opens, closes at 55°F (12.8°C), and 5 minute short cycle
delay. Settings are adjustable.
