Preparation And Work Procedure; Disassembling System Components; Exchanging The Refrigerant; Replacing A Compressor - Emerson Copeland EazyCool ZX Series Application Manuallines

5.3

Preparation and work procedure

A work procedure shall be provided in the preparation stage. All maintenance staff and other
personnel working at the site shall be instructed on the nature of the work being carried out.
If any work is to be conducted on the refrigeration systems or any associated parts, appropriate fire
extinguishing equipment shall be provided. Dry powder or CO
appropriate. Confirm that appropriate fire extinguishing equipment is available near the work area.
Prior to starting to work on systems containing flammable refrigerants, safety checks are necessary
to ensure that the risk of ignition is minimized.
Work shall be undertaken under a controlled procedure so as to minimize the risk of a flammable
gas or vapour being present while the work is being performed.
Avoid working on systems filled with flammable refrigerant in a confined space.
5.4

Disassembling system components

When disassembling system components the recommendations below shall be followed:
▪ Recover refrigerant and evacuate system using an A2L-dedicated recovery unit and vacuum
pump. All the refrigerant shall be recovered to avoid significant release. Ensure that the outlet of
the vacuum pump is not close to any potential ignition source and that ventilation is available.
▪ Flush system with inert gas (dry nitrogen). Compressed air or oxygen shall not be used for purging
refrigerant systems.
▪ Disassemble components with a cutting tool.
5.5

Exchanging the refrigerant

WARNING
Air/A2L mixture in a potentially flammable atmosphere! Fire hazard! In
any case avoid air/A2L mixture in the refrigeration system. Make sure that the
system is filled with pure A2L refrigerant. In the event that the refrigerant needs
replacing, the charge should be recovered using A2L-qualified refrigerant
recovery unit and recycling bottles.
For qualified refrigerant and oil, see paragraph 2.6.1.
5.6

Replacing a compressor

WARNING
Air/A2L refrigerant mixture! Fire hazard! Use suitable recovery unit and
recycling bottles also for oil disposal as A2L refrigerant may still be solved in
the oil.
For systems using flammable A2L refrigerant, it is mandatory to flush oxygen-
free nitrogen through the piping during the brazing process.
CAUTION
Inadequate lubrication! Bearing destruction! Exchange the accumulator
after replacing a compressor with a burned-out motor. The accumulator oil
return orifice or screen may be plugged with debris or may become plugged.
This will result in starvation of oil to the new compressor and a second failure.
Remove refrigerant and oil completely from the replaced compressor.
When replacing an A2L-refrigerant compressor, the oil has to be drained out of the compressor and
the compressor should be flushed with dry nitrogen. DO NOT close the stubs with plugs.
In the case of a motor burnout, the majority of contaminated oil will be removed with the compressor.
The rest of the oil is cleaned through the use of suction and liquid line filter driers. A 100 % activated
alumina suction line filter drier is recommended but must be removed after 72 hours. It is highly
recommended to replace the suction accumulator, if the system contains one. This is because
the accumulator oil return orifice or screen may be plugged with debris or may become plugged
shortly after a compressor failure. This will result in starvation of oil to the replacement compressor
and a second failure. When a compressor is exchanged in the field, it is possible that a major portion
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fire extinguishers are considered
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