Carrier CDF-20Q7 Owner's Manual page 13

SAFETY PRECAUTIONS
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 manufacturer if in doubt.
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 in recovery units and especially not in cylinders. If compressors or compressor oils are to be
removed, ensure that they have been evacuated to an acceptable level to make certain that 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 accelerate this process. When oil is drained from a system, it shall be carried out safely.
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