Norsup 7026965, Installation Instructions Manual

Page: 33 / 273

5. MAINTENANCE AND INSPECTION
When breaking into the refrigerant circuit to make repairs or for any other purpose
conventional procedures shall be used. However, it is important that best practice is followed
since flammability is a consideration. The following procedure shall be adhered to:
-
Remove refrigerant;
- Purge the circuit with inert gas;
- Evacuate;
- Purge again with inert gas;
- Open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders. The system
shall be "flushed" with OFN to render the unit safe. This process may need to be repeated
several times. Compressed air or oxygen shall not be used for this task.
Flushing shall be achieved by breaking the vacuum in the system with OFN and continuing
to fill until the working pressure is achieved, then venting to atmosphere, and finally pulling
down to a vacuum. This process shall be repeated until no refrigerant is within the system.
When the final OFN charge is used, the system shall be vented down to atmospheric pressure
to enable work to take place. This operation is absolutely vital if brazing operations on the
pipe-work are to take place.
Ensure that the outlet for the vacuum pump is not close to any ignition sources and there is
ventilation available. working on them.

Labelling
Equipment shall be labelled stating that it has been de-commissioned and emptied of
refrigerant. The label shall be dated and signed. Ensure that there are labels on the equipment
stating the equipment contains flammable refrigerant.

Recovery
When removing refrigerant from a system, either for servicing or decommissioning, it is
recommended good practice that all refrigerants are removed safely.
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 is available. All cylinders to be used are designated for the recovered
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 shutoff
valves in good working order. Empty recovery cylinders are evacuated and, if possible,
cooled before recovery occurs.
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 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 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