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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Ensure regularly that the vibration levels remain acceptable and close to those at the initial unit
start-up. Before opening a refrigerant circuit, purge and consult the pressure gauges.
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Change the refrigerant when there are equipment failures, following related regulations or carry out
a refrigerant analysis in a specialist laboratory.
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If the refrigerant circuit remains open for longer than a day after an intervention (such as a
component replacement), the openings must be plugged and the circuit must be charged with nitrogen
(inertia principle). The objective is to prevent penetration of atmospheric humidity and the resulting
corrosion on the internal walls and on non-protected steel surfaces.
3. Repair safety considerations
Note: It is compulsory to wear personal protection equipment. The insulation must be removed and
warming up must be limited by using a wet cloth. Before opening the unit always ensures that the circuit
has been purged.
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All installation parts must be maintained by qualified and skilled technicians, in order to avoid
material deterioration and injuries to people. Faults and leaks must be repaired immediately. The
authorized technician must have the responsibility to repair the fault immediately. Each time repairs have
been carried out to the unit, the operation of the safety devices must be re-checked.
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Comply with the regulations and recommendations in unit and installation safety standards. If a leak
occurs or if the refrigerant becomes contaminated (e.g. by a short circuit in a motor) remove the
complete charge using a recovery unit and store the refrigerant in mobile containers.
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Repair the leak detected and recharge the circuit with the total R22 charge, as indicated on the unit
name plate. Certain parts of the circuit can be isolated. Only charge liquid refrigerant R22 at the liquid
line. Ensure that you are using the correct refrigerant type before recharging the unit. Charging any
refrigerant other than the original charge type R22 will impair machine operation and can even lead to a
destruction of the compressors. The compressors operating with this refrigerant type are lubricated with
synthetic oil.
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Do not use oxygen to purge lines or to pressurize a machine for any purpose. Oxygen gas reacts
violently with oil, grease, and other common substances.
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Never exceed the specified maximum operating pressures. Verify the allowable maximum high- and
low-side test pressures by checking the instructions in this manual and the pressures given on the unit
name plate.
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Do not use air for leak testing. Use only refrigerant or dry nitrogen.
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Do not unweld or flame cut the refrigerant lines or any refrigerant circuit component until all
refrigerant (liquid and vapour) has been removed from chiller. Traces of vapour should be displaced with
dry air nitrogen. Refrigerant in contact with an open flame produces toxic gases.
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The necessary protection equipment must be available, and appropriate fire extinguishers for the
system and the refrigerant type used must be within easy reach.