Microprocessor Controller
CRR DF Model - Microprocessor Controller
| Temperature Controller: | |
| CRR-40 DF MP4000 | MP4000 microprocessor |
| Description | MP4000 is a controller module for the Thermo King units. Additional requirements can be met by means of expansion modules. The MP4000 is solely responsible for temperature regulation of the reefer container, but other monitoring equipment can be used in conjunction with the MP4000, such as a chart recorder. |
| Setpoint Range | -65.0 to -10.0 C (-85.0 to +14.0 F) |
| Digital Temperature Display | -80.0 to +130.0 C (-112.0 to +266.0 F) |
| Controller Software (Original Equipment): | See controller identification decal |
| Defrost Initiation: | |
| Evaporator Coil Sensor Coil |
Coil must be below 18 C (65 F) to initiate defrost by demand, timer or manual switch. -Manual Switch or Demand Defrost Initiation: Defrost cycle starts when technician or controller request defrost initiation. -Timed Defrost Initiation: Defrost cycle starts 1 minute after the hour immediately following a defrost timer request for defrost initiation. For example, if the defrost timer requests a defrost cycle at 7:35, the defrost cycle will start at 8:01. Datalogger will record a Defrost event for each interval in which a Defrost cycle is pending or active (i.e. both the 8:00 and 9:00 data logs). |
| Demand Defrost | Demand Defrost function initiates defrost when the temperature difference between the return air sensor and setpoint increases to a preset value and a minimum of 6 hours of compressor ON (running) time have elapsed since the previous defrost; indicating the presence of frost or ice |
| Defrost Timer: Frozen Mode | Initially every 12 hours of compressor operation. Then defrost interval increases 6 hours each time a timed defrost occurs without a demand defrost in between. Maximum time interval in frozen mode is 36 hours of compressor operation. Defrost timer resets if the unit is Off more than 12 hours or the setpoint is changed more than 5 C (9 F) |
| Defrost Termination: | |
| Evaporator Coil Sensor | Frozen mode: Terminates defrost when coil sensor temperature rises to 18 C (64 F) or exceeds 8 C (46 F) for 35 minutes above 440 volts and 45 minutes below 440 volts |
| Interval Timer | Terminates defrost 90 minutes after initiation if coil sensor has not terminated defrost (120 minutes if power supply is less than 55 Hz) |
| Time/Temperature Function | If the evaporator coil sensor exceeds 8 C (46 F) for 15 minutes, the controller terminates defrost |
| Power Off | Turning unit On/Off switch Off terminates defrost |