MCAC-CTSM-2018-1
Flooded type water cooled screw chiller (MIC)
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3. Replace the drain plug in the cooling tower pump if it was removed at shutdown time the previous
season.
4. Install fuses in the main disconnect switch (if removed).
5. Reconnect water lines and turn on the supply water. Flush the 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 help force all the water out and decrease the
corrosion. Water permitted to remain in the piping and vessels can rupture these parts in freezing
temperatures.
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. Use a
reliable water treatment company.
6. Remove the condenser heads at least once a year to inspect the condenser tubes and clean if
required.
Recommended maintenance schedule
This chapter describes the preventive maintenance of Midea screw chiller. Correct maintenance and
timely service will keep the chiller in the best condition and give the best performance, and prolong its
service life.
The customer must appoint an equipment management engineer and specially-assigned operator to
perform the daily and scheduled maintenance. The repair work should be done by large maintenance
company that is qualified to do the job. It is better to make a maintenance agreement with the local
Midea service center when the warranty guarantee reliable operations.
Note: Repair work caused by incorrect maintenance within warranty will lead to extra charges.
Daily maintenance
The basic work of unit maintenance is to accurately record the operation parameters of the unit at certain
intervals (e.g. 2 hours) everyday. Fill the operation parameter table which contains such key parameters
such as high/low pressure, suction/discharge temperature, degree of sub-cooling/overheat degree. True
and complete records of operating parameters are useful for analyzing and forecasting the trend of unit
