Thermo King RD-MT - Unit Operation; Defrost; Operating Modes

Remote Evaporator Unit Description
153
The Spectrum multi-temperature refrigeration
system provides heavy duty temperature control
for multiple compartment trucks. The system
provides direct expansion cooling in all cargo
compartments.
Heat and Defrost is provided in all compartments
by circulating hot refrigerant gas through the
evaporators.
The remote evaporators are ceiling mounted units.
Unit Operation
The remote evaporator cycles between Cool, Null
and Heat to maintain the cargo’s compartment(s)
at the setpoint. The operating modes include Cool,
Null, Heat and Defrost.
Power to run the direct current fan motor is
supplied by the alternator in the condensing unit.
Defrost
The Defrost mode can be initiated any time the
evaporator coil temperature is below 45 F (7 C).
Defrost is initiated automatically by the controller
or manually by selecting the Manual Defrost.
The evaporator fan stops during Defrost. The
Defrost mode will continue until the evaporator
coil temperature rises to 52 F (11 C), causing the
controller to terminate Defrost. After Defrost, the
evaporator may shift back to Cool, Null or Heat.
Operating Modes
Remote evaporator operating modes are:
• Cool
• Null
• Heat
• Defrost
NOTE: The controller locks out heat at setpoints
below 15 F (-9.4 C).
Unit Features
• Direct Expansion Evaporator Coil
• 12 Vdc Fan Motor
• Aluminum Housing
• Liquid Line Solenoid
• Hot Gas Solenoid
• Suction Line Solenoid
• Liquid Return Check Valve
Unit Protection Devices
• Fuses in condensing unit (located on interface
board)
Serial Number Location
Unit: Nameplate on the right end of the unit frame.
Figure 82: Serial Number Location
1. Nameplate on Right End of Unit Frame
1
ARD023