22
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
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
Tr a n q u i l i t y
®
2 2 ( T Y ) S e r i e s
R e v. : 1 2 / 1 7 / 1 4
Electrical - Power & Low Voltage Wiring
ELECTRICAL - LOW VOLTAGE WIRING
Thermostat Connections
- The thermostat will be wired
to the DXM2 board located within the unit control box.
Refer to the unit wiring diagram for specifi c details.
Low Water Temperature Cutout Selection
- The DXM2
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). 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 60°F [15.6°C] must include the
optional water/refrigerant circuit insulation package to
prevent internal condensation.
