Midea LSBLG255/MZ, Техническое и сервисное руководство

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MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control)
95
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Chilled water cycling
Seek the possible leakage on the unit and the pipe joint with leak detector. Expel the water from
condenser and evaporator to see whether there’s leakage on water inlet and outlet. Leak can be found
with electronic detector, torch detector or soap water. The work looking for refrigerant leakage should be
carried out at least once/month.

Electrical control system
For insulation resistance, check it monthly and it
should be over 1MΩ when measuring with ohmmeter of
500VDC. Check the running current and compare with the rated value (refer to Table.9). Check the
conductibility of wire and verify
whether it’s intact and well connected. Fasten the loose bolts. Check
other components such as electromagnetic contactor, rotary switch, auxiliary relay, time relay and
thermostat whether they are all normal monthly.
Training User Operator
The commissioning process includes training user operators in the following aspects:
1) Stress the safety in shutdown and operation processes.
2) Require the users to carefully read the operation manual of the unit.
Explain to the users that operation of the unit shall be carried out strictly as per the steps and
methods specified in the operation manual. If anyone has any problems about descriptions in the
manual, he shall enquire after-sale personnel or professionals in the factory and carry out the
operation only when he understands it. Any deviation in the installation of the unit from the
requirements in the manual shall be pointed out to the part responsible for installation, and the
after-sale personnel or professionals in the factory will determine whether change is necessary.
3) Short-connection is forbidden when all protection functions of the unit are normal. Ensure all
protection functions are available and reliable.
Various protection switches in the unit are for safety of the unit or user, and are not permitted to be
short connected in principle. If short-connection is required for commissioning, the operation shall
be done by the after-sale personnel or professionals in the factory on site. After the commissioning,
connect the protection switches to the system before starting up the unit for long-time running.
4) Open the water pump and wait until the water flow is stable before starting up the master
compressor. For shutdown, the water pump must be closed in a delayed time. It is not allowed to
forcibly close the water pump when the master compressor is still running. If the water pump fails,
and the flow switch does not jump, the unit must be emergently shut down.
5) The unit must be disconnected from the power supply during inspection or replacement of the lines
of the unit.
If it is required to tighten the line bank screw or replacing the wire and element in the electrical
cabinet during commissioning and maintenance, it shall be down when the power supply is
disconnected. Similar operations by the user in later maintenance and service shall also be done
when the power supply is disconnected.
6) The non-user parameters in the touch screen of the unit and electronic expansion valve control
module are forbidden to be changed.
The non-user parameters in the touch screen of the unit and electronic expansion valve control
module are directly related to the performance and reliability of the unit, and are not allowed to be