MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control)
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4. Install fuses in main disconnect switch (if removed).
5. Reconnect water lines and turn on supply water. Flush condenser and check for leaks.
Annual Shutdown
Where the chiller can be subject to freezing temperatures, the condenser and chiller must be drained of
all water. Dry air blown through the condenser will aid in forcing all water out and decreasing the
corrosion. Water permitted to remain in the piping and vessels can rupture these parts if subjected to
freezing temperature.
If the chiller is used in areas where the ambient temperature will fall below 0
℃
, forced circulation of
antifreeze through the water circuits is one method of avoiding freeze up.
1. Take measures to prevent the shutoff valve in the water supply line from being accidentally turned on.
2. If a cooling tower is used, and if the water pump will be exposed to freezing temperature, be sure to
remove the pump drain plug and leave it out so any water that can accumulate will drain away.
3. Open the compressor disconnect switch, and remove the fuses.
4. Check for corrosion and clean and paint rusted surfaces.
5. Clean and flush water tower for all units operating on a water tower. It should be recognized that
atmospheric air contains many contaminants that increase the need for proper water treatment. The
use of untreated water can result in corrosion, erosion, sliming, scaling or algae formation. It is
recommended that the service of a reliable water treatment company be used.
6. Remove condenser heads at least once a year to inspect the condenser tubes and clean if required.
Recommended maintenance schedule
This chapter shows the preventive maintenance of Midea screw chiller. Correct maintenance and timely
service will make the chiller in the best condition and with best performance, beside, it can prolong the
lifespan of chiller.
The customer has responsibility to appoint qualified equipment management engineer and
specially-assigned operator to do the daily and scheduled maintenance. The repair work should be done
by big mainten
ance agency that is qualified to do the job. It’s better to make maintenance agreement
with local customer service centre of Midea after chiller out of warranty, to keep the chiller always under
effective service and guarantee reliable operation.
Note: Repair work caused by incorrect maintenance within warranty will lead to extra charges.
Daily maintenance
The basic work of unit maintenance is to truly record the operation parameters of unit at certain intervals
(e.g. 2hours) everyday. Fill the operation parameter table which contains such key parameters as
high/low pressure, suction/discharge temperature, degree of sub-cooling/overheat degree. True and
complete records of operation parameters are useful for analyzing and forecasting the trend of unit
operat
ion. It’s good for finding and forecasting the problem that may occur and taking measures in time.
For example, by analyzing the record of a whole month, you may find that the temperature difference of
condensing temperature and leaving cooling water temperature may become bigger. It means that the
cooling water is dirty or water hardness is big, and it is scaling constantly. So it’s compulsory to perform
