Water-Side Auto Anti-Freezing In Winter; Control Of Heating Tape On Chassis; Control Of Fan; Control Of Compressor - Gree GRS-CQ6.0Pd/Na-K Service Manual

AIR-TO-WATER HEAT PUMP CONTROL
2.1.2 The condition of quit defrosting mode:
Under defrosting mode, if the continual defrosting time is over the set continual time of
defrosting（default 10min） ，and the defrosting temperature is over the set stopping
temperature(default 15℃) ,the unit will restart running heating mode, and the 4-way valve
will turn on and the outdoor fan will run.

2.2 Water-side Auto Anti-freezing in Winter

In low temperature, When the compressor stops (including normal or abnormal stop of the
unit), if auxiliary heat is lower than 3 ℃,water pump will automatically operate and 30s
later the compressor operates.
When outlet water temperature is less than 20℃，the unit will operate while it will stop
when the outlet water temperature is more than 20 ℃.
However, if there is malfunction of the unit, anti-freezing operation will be started by indoor
electric heater (two sets).

2.3 Control of Heating Tape on Chassis

When heating operation starts in low temperature, in order to prevent the condensation
water generated by defrosting from freezing in chassis, which will incur malfunction of
drainage, the heating tape is installed in chassis. If the ambient temperature is lower than
0 ℃ , when the compressor operates, electric heating will operate; if the ambient
temperature is higher than 2 ℃ or compressor stops, the electric heating will stop.

2.4 Control of Fan

In cooling, the outdoor fan will adjust fan speed according to pressure detected by high
pressure sensor.
In heating or water heating, the fan will adjust fan speed according to ambient temp.

2.5 Control of Compressor

Output capacity of compressor is adjusted according to the comparison of current outlet
water temperature and setting outlet water temperature or the comparison of indoor
ambient temperature and setting indoor temperature;
The output capacity will not be adjusted within 6 min after the compressor operates; once
compressor stops, it can't be started within at least 3 min.

2.6 Control of Electric Expansion Valve

In heating or water heating operation, electric exchange valve is adjusted according to
superheat degree of plate-type heat exchanger.
In cooling operation, electric exchange valve is adjusted according to superheat degree of
outdoor heat exchanger.
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