Control To The Fan; Control To The 4-Way Valve; Control To The Water Pump; Control The Electric Expansion Valve - Gree EVO Serie Manual De Instrucciones

When the unit is controlled by the room temperature, the output frequency of the compressor is adjusted by the
difference between the actual room temperature and the room temperature set point.
2�5 Control to the Fan
Under the cooling mode, the running frequency of the fan is adjusted according to pressure at the high
pressure side. Under the heating mode, the running frequency of the fan is adjusted according to the pressure
at the low pressure side. During defrosting, the fan stops and resumes operation when defrosting ends up.
2�6 Control to the 4-way Valve
The 4-way valve always keeps on under the cooling mode and will off after the compressor starts up under
the heating mode. When the unit comes into defrosting, the 4-way valve will be on and resume the off status
when defrosting ends up. For shutdown under the heating mode, the 4-way valve will be closed after the
compressor stops.
2�7 Control to the Water Pump
The water pump firstly will run at the initialized speed and then adjust the speed according to the entering/
leaving water temperature difference. When the temperature difference is large, the fan runs at the high speed.
When the temperature difference is small, the fan runs at the low speed.
2�8 Control the Electric Expansion Valve
There are two electric expansion valves for two-stage throttling control. The opening angle of the first-stage
electric expansion valve is adjusted based on the ratio of readings of the high-pressure sensor, low-pressure
sensor and enthalpy-adding sensor. The opening angle of the second-stage is adjusted based on the suction
superheating degree.
2�9 Protection Control
(1) Compressor Low-pressure Protection
When it is detected continuously that pressure at the low side is too low, then low-pressure protection will
occur and this error will be displayed at the controller, all loads act as per the shutdown sequence. This error is
unrecoverable and can be cleared unless repowered on.
(2) High Discharge Temperature Protection
When it is detected continuously that the discharge temperature is higher than the recoverable temperature,
the electric expansion valve will turn to the maximum opening angle with large step until the discharge
temperature is lower than the recoverable temperature. However, if this condition remains, the compressor will
restrict the frequency output or lower its frequency three times. At any time, if it is detected that the discharge
temperature is higher than the set point for protection for three seconds, the compressor will stop and the unit
comes into high discharge temperature protection.
(3) Refrigerant Loss Protection
When the unit receives the "On" demand (through On/Off key operation or automatic freeze protection), it
will immediately detect the temperature of the high-pressure sensor and the environment temperature. If the
temperature of the high-pressure sensor is lower than the set point, this error will be displayed with the error
indicating LED flashing. In this case, the unit is not allowed to start up unless this error does not exit. Once the
compressor starts up, the system will no longer detect refrigerant loss protection.
(4) Water Pump Protection
When it is detected continuously for three seconds that the unit comes into water pump overload protection,
then all loads will stop. Three minutes later, all loads resume normal operation. When it is detected three times
within 60 minutes that the unit comes into water pump overload protection, this error will be displayed and is
unrecoverable. The unit is allowed to restart only after the unit is shut down manually and this error is cleared.
(5) Compressor Hi-pressure Protection
In any case, when it is detected that the high-pressure switch acts, the unit will come into high-pressure
protection three seconds later. This protection is unrecoverable.
(6) Flow Switch Protection
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Unit Control