1 Integral Control Concept
1�1 Control Principle Diagram
1. The environment temperature is detected by the sensor installed at fins of the finned heat exchanger,
which is mainly used to control the initialization steps of the fan and the electric expansion valve and also limit
the maximum running frequency of the compressor. When this sensor fails, the main board will detect it and
deliver this error message to the controller and then the unit will fail to start up or shut down.
2. The defrosting temperature is detected by the sensor installed at the defrosting pipes of the finned
heat exchanger, which is mainly used to control defrosting. When this sensor fails at the heating mode, the
compressor will stop and this error will be displayed at the controller. When it fails at the cooling mode, the
compressor continues to run but this error will be displayed at the controller.
3. The discharge temperature is detected by the sensor installed at the discharge pipe of the compressor,
which is mainly used for high discharge temperature protection. When this sensor fails, this error will be
displayed at the controller, all loads will stop. Then, the main unit will resume normal running when this error is
eliminated.
4. The suction temperature is detected by the sensor installed at the suction pipe of the compressor,
which is mainly used to control superheating degree. When this sensor fails, this error will be displayed at the
controller, all loads will stop. Then, the main unit will resume normal running when this error is eliminated.
Main Unit
RS485
Main Unit
Output Control
Field Instalaltion
Main Board
Field Instalaltion
Input Control
1
Unit Control
Power
Supply