Automatic Anti-Freezing Operation; Control To The Compressor; Control To The Fan; Control To The 4-Way Valve - Gree A Series Service Manual

A Series Modular-type Air-cooled (Heat Pump) Chiller
4.3.2.3 Shutdown
Manual or timing shutdown: compressor stops firstly, and the auxiliary electric heater
second, and then the fan and water pump.
Shutdown upon the temperature set point: the compressor and the fan stop firstly, while the
water pump keeps running.
Shutdown upon errors: the compressor stops firstly and the fan, while the water pump keeps
running.
4.3.3

Automatic Anti-freezing Operation

For each single unit, when the anti-freezing temperature or the leaving water temperature is
lower than the limit value, freeze protection will work; when the anti-freezing temperature and
the leaving water temperature go higher than the normal value, freeze protection will quit.
when the anti-freezing temperature and the leaving water temperature are between the limit
value and the normal value, the unit will keep the current operation status.
4.3.4

Control to the Compressor

1)"First On, First Off"
"First On, First Off"/ "First Off, First On" control indicates the numbered compressor which is
started/stopped firstly will then be stopped/started firstly.
4.3.5

Control to the Fan

The fan will start when the unit is turned on and will stop when the compressor is turned off.
During defrosting, the fan does now work but will back to working when defrosting exists.
4.3.6
Control to the 4–way Valve
At the cooling mode, the 4–way valve will not work when the unit goes for defrosting or the
unit is OFF. At the heating mode, the 4–way valve will work when the unit is turned on or
defrosting quits.
4.3.7

Control to the Water Pump

When there is demand for any single unit, the water pump will start. When there is no
demand for all water pumps, the water pump will stop.
4.3.8

Control to the Electronic Expansion Valve

The electronic expansion valve will be initialized when the controller is powered on for the
first time.
After the compressor has been started, the electronic expansion valve starts to adjust its
opening angle
4.3.9

Protection

4.3.9.1 Recoverable Protection
(1)Fault of Communication
The unit will stop when it receives no signal from the controller. Once there is any commu-
nication fault for any unit, all compressors of this unit will stop and then the water pump will
follow.
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