26
Installation, Operation & Maintenance - HEH/HEV Series
Electrical - Power & Low Voltage Wiring
CAUTION!
Use only copper conductors for field installed
electrical wiring. Unit terminals are not designed to accept
other types of conductors.
WARNING!
Disconnect electrical power source to prevent
injury or death from electrical shock.
�
CAUTION!
�
�
WARNING!
�
Power Connection -
Line voltage connection is made by
connecting the incoming line voltage wires to the “L” side of
the contractor as shown in the unit wiring diagram. Consult
electrical data tables for correct fuse size.
460 volt units require a neutral wire.
Transformer -
All 208/230 voltage units are factory wired
for 208 volt. If supply voltage is 230 volt, installer must
rewire transformer. See wire diagram for connections.
ELECTRICAL - LOW VOLTAGE WIRING
Thermostat Connections
- The thermostat will be wired
to the CXM/DXM2 board located within the unit control
box. Refer to the unit wiring diagram for specific details.
CAUTION!
Use only copper conductors for field installed
electrical wiring. Unit terminals are not designed to accept
other types of conductors.
Electrical - Line Voltage
- All field installed wiring,
including electrical ground, must comply with the National
Electrical Code as well as all applicable local codes. Refer to
the unit electrical data for fuse sizes. Consult wiring diagram
for field connections that must be made by the installing (or
electrical) contractor. All final electrical connections must be
made with a length of flexible conduit to minimize vibration
and sound transmission to the building.
General Line Voltage Wiring
- Be sure the available
power is the same voltage and phase shown on the unit
serial plate. Line and low voltage wiring must be done in
accordance with local codes or the National Electric Code,
whichever is applicable.
Low Water Temperature Cutout Selection
- The CXM/
DXM2 control allows the field 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 refrigeravnt 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 flow 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.
Summary of Contents for Comfort-Aire Century HE Series
Page 1: ...www marsdelivers com Installation Operation and Maintenance HEH HEV Series...
Page 32: ...32 Installation Operation Maintenance HEH HEV Series Typical Wiring Diagram Single Phase Unit...
Page 33: ...33 Installation Operation Maintenance HEH HEV Series Typical Wiring Diagram Three Phase Unit...
Page 34: ...34 Installation Operation Maintenance HEH HEV Series Typical Wiring Diagram 460 Volt Unit...