Ingersoll-Rand Thermo King CRR DF MPC2000, Maintenance Manual

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Microprocessor Controller
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• Datalogger Menu: Menu screens in this group display temperature log, event log, set log time and
PTI log.
• RMM (Remote Monitoring) State: Menu screen show current remote monitoring state (Offline,
Zombie or Online).
General Theory of Operation
The MPC2000 and MPC2000ID controllers use advanced solid-state integrated circuits to monitor and
control unit functions. The controller monitors inputs from:
• Return air sensor
• Supply air sensor
• Evaporator coil sensor
• Ambient sensor
• USDA (Spare) sensors 1, 2 and 3
• R-134a compressor discharge line temperature sensor
• R-23 compressor discharge line temperature sensor
• Phase measuring circuits
• Current measuring circuits
• Voltage measuring circuits
Output signals from the controller automatically regulate all unit functions including:
• Compressor operation
• Condenser fan operation
• Evaporator fan motor operation
• Liquid line solenoid valve
• Electric heaters
• Phase selection
Frozen Loads (Setpoint at -10 C [14 F] and Below)
NOTE: CRR DF units are designed to haul deep frozen cargo only at setpoints between -10 C (14 F)
and -60 C (-76 F).
At setpoints of -10 C (14 F) and below, the microprocessor controls unit operation based on the return air
sensor temperature and setpoint temperature.
The system operates on Full Cool to provide accurate control of frozen cargo. If the return air sensor
becomes disconnected or fails while it is being used to control unit operation, the controller will
automatically operate the unit continuously on Full Cool.