Maintenance - Midea LSBLG MCF Series Technical & Service Manual

Flooded type water cooled screw chiller (MIC)
5) Disconnect the unit from the power supply during inspection or replacement of the lines.
Tighten the line bank screw or replace the wire and element in the electrical cabinet during
commissioning and maintenance, only when the power supply is disconnected. Similar operations
in subsequent maintenance and servicing must also be done when the power supply is
disconnected.
6) Do not change non-user parameters on the touch screen of the unit and electronic expansion valve
control module.
Relate to the performance and reliability of the unit, and must not be changed. Even if it is required
to adjust some parameters due to special local climate, it must be done by or under the instructions
of after-sales or factory personnel.
7) If the unit behaves unexpectedly, do not forcibly start up the unit unless under the instructions of
professionals.
Exceptional temperature, pressure, sound, or vibration, etc. of the unit when it is running must be
clearly recorded in details, and reported to after-sales or factory personnel. Do not forcibly start up
the unit unless permitted.

2. Maintenance

If the problem is serious, contact your local Midea office or your local representative for assistance.
Cleaning Heat Exchangers
Check the chiller tightness and whether there's leak in the heat exchange tubes. It is necessary to do
nondestructive inspection for the principal weld (longitudinal and circumferential weld of
evaporator/condenser barrel) of the pressure vessel. Inspect and clean cooler tubes at the end of the
first operating season. Tube conditions in the exchanger will determine the scheduled frequency for
cleaning, and will indicate whether water treatment is adequate in the water circuit. Too much scale will
cause a big loss in capacity and efficiency.
Refer to the following pressure-temperature curve for the condition of heat exchangers:
High pressure-cooling water temperature (high pressure outside of 0.6~1.2MPa is abnormal)
Low pressure-chilled water temperature (low pressure outside of 0.14~0.37MPa is abnormal)
Fig.26 High pressure at full load (standard unit)
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MCAC-CTSM-2018-1