Midea LSBLG255/MZ, Техническое и сервисное руководство

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DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03
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11) The drain connection is arranged on the evaporator cylinder. The drain outlet has been
equipped with a 1/2’’ plug.
12) In order to expel the air from water system, install an automatic discharge valve on the highest
place of local water pipe and the horizontal pipe should be up tilted for about 1/250 degree.
13) The thermometer and pressure gauge are arranged on the straight pipe sections of the water
inlet pipeline and drain pipeline, and their installation places shall be far away from the elbows.
The pressure gauge installed shall be vertical to the water pipe, and the installation of the
thermometer shall ensure that its temperature probe can be inserted into the water pipe directly.
14) Each low point shall be fitted with a drain connection so as to drain the remaining water in the
system. Before operating the unit, connect the stop valves to the drain pipeline, respectively
near the water inlet connection and drain connection. The by-pass pipeline shall be provided
between the water inlet pipe and drain pipe of the evaporator, convenient for cleaning and
maintenance. Use of flexible connections can reduce vibration transfer.
15) The chilled water pipeline and expansion tank shall be subjected to insulation treatment, and
the maintenance and operation part shall be reserved on the valve connections.
16) After the air-tightness test is carried out, and the insulation layer is applied on the pipeline, so
as to avoid heat transfer and surface condensation; the insulation layer shall be covered by
moisture-proof seal.
17) Any water piping to the unit must be protected to prevent freezing. There are reserved
terminals for the auxiliary electrical heater. Logic in PCB will transmit ON/OFF signal by
checking the leaving evaporator water temperature.
Note: The unit only supplies the ON/OFF signal, but not the 220V power. If a separate
disconnect is used for the 220V supply to the cooler heating cable, it should be clearly marked
so that it is not accidentally shut off during cold seasons
18) If the unit is used as a replacement chiller on a previously existing piping system, the system
should be thoroughly flushed prior to unit installation and then regular chilled water analysis
and chemical water treatment is recommended immediately at equipment start-up.
19) Power on the chilled water pump, and inspect its rotation direction. The correct rotation
direction shall be clockwise; if not, re-inspect the wiring of the pump.
20) Start the chilled water pump to circulate water flow. Inspect the water pipelines for water
leakage and dripping.
21) Commission the chilled water pump. Observe whether the water pressure is stable. Observe
the pressure gauges at the pump inlet and outlet, and the readings of the pressure gauges and
the pressure difference between the inlet and outlet change slightly when the water pressure is
stable. Observe whether the operating current of the pump is within the range of rated
operating current; inspect whether the resistance of the system is too large if the difference
between the operating current and rated value is too big; eliminate the system failures until the
actual operating current is satisfied.
22) Inspect whether the water replenishing device for the expansion tank is smooth, and the auto
discharge air valve in the water system enables auto discharge. If the discharge air valve is a