Midea Aqua Tempo Super II Series Technical & Service Manual page 50

MCAC-ATSM-201704 Aqua Tempo Super II Series DC Inverter Air-cooled chiller unit (50Hz)
b. Water must enter the heat exchanger through the inlet; otherwise the performance of the unit will decline.
c. The inlet pipe of the evaporator must be provided with a water flow switch, to realize flow-break protection
for the unit. Both ends of the water flow switch must be supplied with horizontal straight pipe sections whose
diameter is 5 times that of the inlet pipe. The water flow switch must be installed in strict accordance with
"Installation & Regulation Guide for Water flow switch". The wires of the water flow switch should be led to
the electric cabinet through shielded cable. The working pressure of the water flow switch is 1.0MPa, and its
interface is 1 inch in diameter. After the pipelines are installed, the water flow switch will be set properly
according to the rated water flow of the unit.
d. The pump installed in the water pipeline system should be equipped with starter. The pump will directly
press water into the heat exchanger of the water system.
e. The pipes and their ports must be independently supported but should not be supported on the unit.
f. The pipes and their ports of the heat exchanger should be easy to disassemble for operation and cleaning,
as well as inspection of port pipes of the evaporator.
g. The evaporator should be provided with a filter with more than 40 meshes per inch at site. The filter
should be installed near to the inlet port as much as possible, and be under heat preservation.
h. The by-pass pipes and by-pass valves as shown in the figure of "Connection drawing of pipeline system"
must be mounted for the heat exchanger, to facilitate cleaning of the outside system of water passage before
the unit is adjusted. During maintenance, the water passage of the heat exchanger can be cut off without
disturbing other heat exchangers.
i. The flexible ports should be adopted between the interface of the heat exchanger and on-site pipeline, to
reduce transfer of vibration to the building.
j. To facilitate maintenance, the inlet and outlet pipes should be provided with thermometer or manometer.
The unit is not equipped with pressure and temperature instruments, so they need to be purchased by the
user.
k. All low positions of the water system should be provided with drainage ports, to drain water in the
evaporator and the system completely; and all high positions should be supplied with discharge valves, to
facilitate discharging air from the pipeline. The discharge valves and drainage ports should not be under
heat preservation, to facilitate maintenance.
l. All possible water pipes in the system to be chilled should be under heat preservation, including inlet pipes
and flanges of the heat exchanger.
m. The outdoor chilled water pipelines should be wrapped with an auxiliary heating belt for heat preservation,
and the material of the auxiliary heat belt should be PE, EDPM, etc., with thickness of 20mm, to prevent the
pipelines from freezing and thus cracking under low temperature. The power supply of the heating belt
should be equipped with an independent fuse.
n. When the ambient temperature is lower than 2℃, and the unit will be not used for a long time, water inside
the unit should be drained. If the unit is not drained in winter, its power supply should not be cut off, and the
fan coils in the water system must be provided with three-way valves, to ensure smooth circulation of the
water system when the anti-freezing pump is started up in winter.
o. The common outlet pipelines of combined units should be provided with mixing water temperature sensor.
Warning:
● For the water pipeline network including filters and heat exchangers, dreg or dirt may seriously damages
the heat exchangers and water pipes.
● The installation persons or the users must ensure the quality of chilled water, and de-icing salt mixtures
and air should be excluded from the water system, since they may oxidize and corrode steel parts inside the
heat exchanger.
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