Gree A Series Service Manual page 137

A Series Modular-type Air-cooled (Heat Pump) Chiller
1) let the water pump run for another 1-2 hours.
2) 1-2 hours later, change the cleaning solution to anti-rusting agent. Then, drain the water
system and check the water quality. If water is cloudy, then it indicates the cleaning ef-
fect is satisfactory.
3) open the water inlet to see if scale on the shell and tube has been removed. If not, clean
the shell and tube separately again by the skilled serviceman and then rinse them. If
there is still sand, scale and other foreign matters at the bottom of the shell and tube, let
cleaning solution in from the inlet pipe and then let the foul water out through the drain
outlet.
4) fully charge the water system and let it run for another 1-2 hours.
5) stop the unit to drain up waste solution. If impossible, drain it with making up water at
the same time until all waster solution has been drained out completely (at this time
water is transparent and PH is 7).
6) repeat steps ④ and ⑤.
7) clean or change the filters in the water system.
8) see if the difference between the entering and leaving water temperature is improved.
(1)although the cleaning agent is innocuous, but care also should be taken not to let it spill
into eyes.
(2)the serviceman with injuries on the hand is not allowed to take this task.
Before and after cleaning, observe the running status of the unit, summarize the cleaning
effect and record the running parameters.
8.2.2.2 Cleaning of the Finned Heat Exchanger
In order to keep fins work efficiently, be sure there are no leaves, cotton wool, insects, and
other contaminants on the outer layer of fins, or they would lead to more energy consumption
and high discharge pressure. Generally, fins should be cleaned after the unit has run for 6-12
months, or more frequently when the environment is polluted more seriously.
(1)Cut off the power supply.
(2)Clean with high-pressure air fins against the direction of the inlet air, or clean with high-
pressure water fins at the direction upright with that of the fins but care must be taken to
control the water pressure to prevent the fins from being pulled down and protect each
electric element. If fins stick with oily matters, clean fins with neutral detergent solution.
(3)The vacuum cleaner and nylon brush also can be used to remove dust and foreign mat-
ters on the surface of the heat exchanger.
8.3
Freeze Protection in Winter
When the unit is not going to be used for a long time, clean and dry the internal and external
surfaces of the unit, and then it would be better to wrap it. Under the subzero climate, the
unused unit should be drained completely so that the shell-and-tube evaporator would not be
NOTE
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