Control; Units' Control - Gree GC202306-I Service Manual

Gree

1.Units' Control

1.1 Schematic Diagram of Units' Control
1.2 Key Control Logics
(1) Control on compressor
After power is connected, start the system by the manual operator and detect the outdoor
ambient temperature sensor. If the outdoor ambient temperature is not lower than -15°C and
when no fault is detected and start up conditions of the compressor are met, the system starts.
(2) Control on fan motor
When start up conditions of the compressor are met, the system starts. The electronic expansion
valve resets and is initialized, and the external fan motor starts. After 10s, the compressor starts.
(3) Control on defrosting
When the unit is heating under low ambient temperature and high humidity, there is be frost on
the surface of the heat exchanger of finned tube. The unit will judge the frost according to the
tube temperature of heat exchanger and operation time. If the frost has affected the heat
exchange of complete unit, the unit will start defrosting. The 4-way valve coil is energized for
reversing. The fan stops operation, and the compressor and electronic expansion valve operates
according to the setting parameters. Meanwhile, tube temperature will be detected by the
pipeline temperature sensor of heat exchanger to judge whether the frost is removed. If yes, the
unit will exit from the defrosting process to resume heating (the loads will resume original
operation status).
(4) Control on antifreeze function
When the heat pump unit is turned off or under fault status, if ambient temperature is lower than
2℃ and water inlet temperature is lower than the set anti-freezing temperature (eg: 5℃), the
water pump will be energized firstly for operation and then the heat pump starts working (if
ambient temperature is lower than the lower temperature limit of unit, the heat pump will be
turned off).

CONTROL

12
SWIMMING POOL HEAT PUMP (R32)