General Description
Superfreezer Model CRR DF units are all-electric, single-piece, refrigeration units with bottom air supply. Each unit is designed for long distance, shipboard or overland transport of deep frozen or frozen cargoes. Each unit mounts in the front wall of the container. Fork lift pockets are provided for installation and removal of the unit.
The frame and bulkhead panels are constructed of aluminum and are treated to resist corrosion. A hinged, removable evaporator compartment door provides easy service access. All operating components except the evaporator coil and buffer receiver tanks can be replaced from the front of the unit.
The unit is equipped with an 18.3 m (60 ft) power cable for operation on 460-380V/3 Ph/60-50 Hz power. For operation on 460-380V/3 Ph/60-50 Hz power, plug the 460-380Vpower cable into the proper power supply.
Each unit is equipped with 460-380V/3 Ph/60-50 Hz electric motors. An automatic phase correction system provides the proper electrical phase sequence for condenser fan and evaporator fan motor operation. Unit power cable is stored below the control box in the condenser section.
CRR DF MP4000 units feature MP4000 microprocessor controller and a datalogger. Additional features include three evaporator fans; USDA Cold Treatment Temperature Recording; and a Remote Monitoring Modem (RMM). For additional unit feature information, see “CRR DF Model Features” on page v of the Introduction.
Cascade Refrigeration System
The CRR DF unit uses a basic cascade refrigeration system to achieve to frozen and deep frozen cargo temperatures between -10 C and -70 C (+14 F and -94 F). (-70 C is the Lowest possible set-point provided the Box Size is set to 10´ or 20´, -65C would be lowest possible set-point for Box Size of 40´). The CRR DF cascade refrigeration system design allows shippers to economically carry cargo at deep frozen temperatures using proven, reliable transport refrigeration system technology.
The CRR DF cascade systems consists of two separate, single-stage refrigeration systems with different refrigerants. One system is a low temperature stage system that uses a hermetic scroll compressor and R-23 refrigerant. The evaporator of the low temperature stage system cools the cargo air, achieving cargo temperatures down to -70 C (-76 F). (-70 C is the Lowest possible set-point provided the Box Size is set to 10´ or 20´, -65C would be lowest possible set-point for Box Size of 40´).
The second system is a high temperature stage system that uses a semi-hermetic reciprocating compressor and R-134a refrigerant. The evaporator of the high temperature stage system cools the condenser of the low temperature stage system through a special plate heat exchanger. The condenser of the high temperature stage system then transfers the cargo heat to the ambient air.
R-134a Semi-hermetic Reciprocating Compressor
The R-134a high temperature stage circuit features a semi-hermetic reciprocating compressor with forced feed lubrication system, ambient compensated internal overload protection and high temperature protection.
R-23 Hermetic Scroll Compressor
The R-23 low temperature stage circuit features a hermetic scroll compressor (one stationary and one orbiting member) with ambient compensated internal overload protection and high temperature protection.
Microprocessor Controller
The MP4000 is an advanced microprocessor controller that has been specially developed for the control and monitoring of refrigeration units. Refer to (MP4000 Controller) for more detailed information.
Power Module Fuses
The PM-4000 Power Module in the unit uses Ultra Fast 20 amp fuses to protect the power module and are not interchangeable with the MP3000 MRB fuses. The fuses from the MP3000 MRB must never be used in the PM 4000 Power Module.
Part number for a PM 4000 Power Module fuse (FF 20 amp 500v and black fuse holder) is: P/N 419286 Fuse & Holder Blk MP4000.
Part number for the MP3000 MRB fuse (F 20 amp 500V and red fuse holder) is: P/N 419318 Fuse & Holder Red MP3000.
Fuse and fuse holder will be sold together as a kit. Individual fuse and holder part number for the MP3000 will supersedes to the kit number once inventory is used up.
Three Evaporator Fans
Three evaporator fans operate continuously to circulate air inside the container. Two-speed fans operate continuously on low speed for deep frozen and frozen cargo (setpoints of -10 C [+14 F] and below).
USDA Cold Treatment Temperature Recording
The datalogger includes provisions for the use of three USDA sensors. These sensors allow temperatures in various areas of the load to be monitored and recorded for United States Department of Agriculture use in monitoring Cold Treatment shipments. The USDA sensors record temperatures from -80.0 C to +10 C (-112.0 F to +50.0 F).
REFCON Remote Monitoring Modem (RMM)
A REFCON remote monitoring modem is provided to permit remote monitoring via the power cable. High speed transmission reads all controller information. Data can also be retrieved from the datalogger via high speed transmission.