Unit Description
5-28
The SR-2/SR-3 multi-temperature refrigeration system provides heavy duty temperature control for multiple compartment
trailers. The system provides direct expansion cooling in all trailer compartments. Non-contaminating refrigerant tap-ins in the
host unit evaporator provide convenient refrigerant piping connections for the remote evaporator(s).
The host unit mounts on the front of the trailer with the evaporator protruding into the trailer. The remote evaporator(s) is a
ceiling mounted SPECTRUM unit.
Heat and defrost is provided in all compartments by circulating hot refrigerant gas through the evaporators.
The remote evaporator(s) are controlled by the SR-2/SR-3 MT Control System through the expansion module. The SR-2/SR-3
MT Control System is located in the host unit. The wire harnesses connect the remote evaporator(s) to the expansion module.
The expansion module is connected to the base controller/interface board assembly through the CAN bus. See “SLXi/SLXe/SLX/
SL-400 SR-2/SR-3 Controller” on page 3-8 and Refer to the SR-2/SR-3 Multi-Temp Microprocessor Controller Diagnostic
Manual for more information about the SR-2/SR-3 MT Control System.
UNIT OPERATION
The remote evaporator cycles between cool, null and heat to maintain the trailer’s compartment(s) at the setpoint. The
operating modes include Cool, Null, Heat, and Defrost.
Power to run the direct current fan motors is supplied by the alternator in the host unit.
When cooling is required, the SR-2/SR-3 MT Control System energizes the remote liquid line solenoid valve. Refrigerant
flows through the evaporator coil to provide cooling.
When the compartment temperature is near setpoint, the SR-2/SR-3 MT Control System de-energizes the remote liquid line
solenoid valve and switches the remote evaporator to null.
The SR-2/SR-3 MT Control System energizes the remote hot gas solenoid when the remote compartment requires heat or
defrost.
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 defrost from the Defrost Prompt Screen for the desired zone.
The evaporator fan stops during defrost. The Defrost mode will continue until the evaporator coil temperature rises to 58 F
(14.5 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
Unit Features
• Direct Expansion Evaporator Coil
• SR-2/SR-3 MT Control System with Expansion Module
• 12 Vdc Fan Motor (with low speed start feature)
• Aluminum Housing
• Liquid Line Solenoid
• Hot Gas Solenoid
• Suction Line Solenoid
• Liquid Return Check Valve
Содержание SLXi Spectrum
Страница 17: ...Safety Precautions 2 5 Warning Decals...
Страница 18: ...Safety Precautions 2 6 Warning Decals Information Decals...
Страница 74: ...Unit Description 5 30...
Страница 128: ...Controller Operation 7 28...
Страница 156: ...Electrical Maintenance 8 28...
Страница 177: ...Engine Maintenance 9 21 Integral Fuel Solenoid Components 1 Integral Fuel Solenoid 2 O ring 3 Fuel Injection Pump Groove...
Страница 234: ...Refrigeration Maintenance 10 22...
Страница 309: ...13 Mechanical Diagnosis TK 482 TK 486 and TK 486V Engines 13 2...
Страница 316: ...Mechanical Diagnosis 13 8...
Страница 322: ...Refrigeration System Diagnosis 14 6...
Страница 332: ...Single Temperature Refrigeration System Diagrams 15 10...
Страница 339: ...Multi Temperature Refrigeration System Diagrams 16 7...
Страница 340: ...Multi Temperature Refrigeration System Diagrams 16 8...
Страница 342: ...Wiring Diagrams and Wiring Schematics 17 2...