Mitsubishi Electric City Multi PURY-EM200YNW-A1, Service Handbook

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[1-2 Handling and Characteristics of Piping Materials, Refrigerant, and Refrigerant Oil ]
BS_01_L
chapter 1 -
9
1
Che
ck Bef
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Se
rvicing
10. Appropriate refrigerant recovery method
1) When removing refrigerant from a system, either for repairing or decommissioning, it is recommended good practice that all
refrigerants are removed safely.
2) When transferring refrigerant into cylinders, ensure that only appropriate refrigerant recovery cylinders are employed. Ensure
that the correct number of cylinders for holding the total system charge are available. All cylinders to be used are designated
for recovering refrigerant and labelled for that refrigerant (i.e. special cylinders for the recovery of refrigerant). Cylinders shall
be complete with pressure-relief valve and associated shut-off valves in good working order. Empty recovery cylinders are
evacuated and, if possible, cooled before recovery starts.
3) The recovery equipment shall be in good working order with a set of instructions concerning the equipment that is at hand and
shall be suitable for the recovery of all appropriate refrigerants including, when applicable, slightly flammable refrigerants. In
addition, a set of calibrated weighing scales shall be available and in good working order. Hoses shall be complete with leak-
free disconnect couplings and in good condition. Before using the recovery machine, check that it is in satisfactory working
order, has been properly maintained and that any associated electrical components are sealed to prevent ignition in the event
of a refrigerant release. Consult dealer if in doubt.
4) The recovered refrigerant shall be returned to the refrigerant supplier in the correct recovery cylinder, and the relevant waste
transfer note arranged. Do not mix refrigerants with different properties in recovery units and especially not in cylinders.
5) If compressors or compressor oils are to be removed, ensure that they have been evacuated to an acceptable level to make
certain that slightly flammable refrigerant does not remain within the lubricant. The evacuation process shall be carried out
prior to returning the compressor to the suppliers. Only electric heating to the compressor body shall be employed to accel-
erate this process. When oil is drained from a system, it shall be carried out safely.
11. Competence of service personnel
(1) General
Special training additional to usual refrigerating equipment repair procedures is required when equipment with slightly flam-
mable refrigerants is affected.
(2) Training
The training should include the substance of the following:
Information about the explosion potential of slightly flammable refrigerants to show that flammables may be dangerous when
handled without care.
(3) Information about the correct working procedures
Commissioning
1) Ensure that the floor area is sufficient for the refrigerant charge or that the ventilation duct is assembled in a correct manner.
2) Connect the pipes and carry out a leak test before charging with refrigerant.
3) Check safety equipment before putting into service.
Maintenance
1) Portable equipment shall be repaired outside or in a workshop specially equipped for servicing units with slightly flammable
refrigerants.
2) Ensure sufficient ventilation at the repair place.
3) Be aware that malfunction of the equipment may be caused by refrigerant loss and a refrigerant leak is possible.
4) Discharge capacitors in a way that won't cause any spark. The standard procedure to short circuit the capacitor terminals usu-
ally creates sparks.
5) Reassemble sealed enclosures accurately. If seals are worn, replace them.
6) Check safety equipment before putting into operation.
7) Carry a portable refrigerant-leak sensor when entering a space with a risk of refrigerant leakage.
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