Ducasa PTL BC 30 C Manual Del Usuario página 72

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.
16. 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.
Ensure that the refrigeration system is earthed prior to charging the system with
refrigerant.
Label the system when charging is complete (if not already).
Extreme care shall be taken not to overfill the refrigeration system. Prior to recharging
the system it shall be pressure tested with OFN. The system shall be leak tested on
completion of charging but prior to commissioning. A follow up leak test shall be carried
out prior to leaving the site.
17. Decommissioning
Before carrying out this procedure, it is essential that the technician is completely
familiar with the equipment and all its detail. It is recommended good practice that
all refrigerants are recovered safely. Prior to the task being carried out, an oil and
refrigerant sample shall be taken in case analysis is required prior to re-use of
reclaimed refrigerant. It is essential that electrical power is available before the task is
commenced.
a) Become familiar with the equipment and its operation.
b) Isolate system electrically.
c) Before attempting the procedure ensure that: Mechanical handling
equipment is available, if required, for handling refrigerant cylinders;
d) All personal protective equipment is available and being used correctly; The
recovery process is supervised at all times by a competent person;
e) Recovery equipment and cylinders conform to the appropriate standards.
f) Pump down refrigerant system, if possible.
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