Proklima 27465097 Bedienungsanleitung Seite 53

shall be recovered from the system. Oxygen free nitrogen (OFN) shall then be
purged through the system both before and during the brazing process.
14.Removal and evacuation
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.
15.Refrigerant Charging procedures
In addition to conventional charging procedures, the following requirements
shall be followed.
-Ensure that contamination of different refrigerants does not occur when using
charging equipment. Hoses or lines shall be as short as possible to minimise
the amount of refrigerant contained in them.
-Cylinders shall be kept upright.
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