Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11
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cleanness work is in urgent need. When the chiller stops for a long time, water in heat exchangers and
pipe system should be drained thoroughly. For newly installed chiller, the filters in water system should
be cleaned after running for 24 hours and then clean the filters quarterly.
Valves and pressure controllers
▲
Safety valves
Inspect the integrity and performance of valves every year. The maintenance of safety valves should be
done by specialized technicians. Take apart the connecting pipe of safety valve, and check it to see
whether there is corrosion, rust, scaling, leakage phenomenon internal (if necessary, replace the safety
valve). And also check other operating valves to see whether it’s smooth when opening or closing them.
▲ High/low pressure switch
Check their performance whether they are in good condition according to “performance of protection
device” monthly, and change the broken one in time. Or the chiller may get damaged when over high
pressure or too low pressure happens.
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.
2.5 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,
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