vidaXL 50762, Operating And Safety Instructions Manual, Page: 26 / 376

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If a leak is suspected, all naked flames shall be removed/
extinguished.
If a leakage of refrigerant is found which requires brazing, all of
the refrigerant shall be recovered from the system, or isolated
(by means of shut off valves) in a part of the system remote
from the leak. For appliances containing flammable refrigerants,
oxygen free nitrogen (OFN) shall then be purged through the
system both before and during the brazing process.
7.3.9 Removal and evacuation
When breaking into the refrigerant circuit to make repairs - or
for any other purpose - conventional procedures shall be used.
However, for flammable refrigerants 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. For appliances containing flammable
refrigerants, 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 purging
refrigerant systems.
For appliances containing flammable refrigerants, 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 that ventilation is available.
7.3.10 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 minimize 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
the appropriate purging gas. 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.
7.3.11 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.
1. Become familiar with the equipment and its operation.
2. Isolate system electrically.
3. Before attempting the procedure, ensure that:
– Mechanical handling equipment is available, if
required, for handling refrigerant cylinders.
– All personal protective equipment is available and
being used correctly.
– The recovery process is supervised at all times by a
competent person.
– Recovery equipment and cylinders conform to the
appropriate standards.
4. Pump down refrigerant system, if possible.
5. If a vacuum is not possible, make a manifold so that
refrigerant can be removed from various parts of the
system.
6. Make sure that cylinder is situated on the scales before
recovery takes place.
7. Start the recovery machine and operate in accordance with
manufacturer's instructions.
8. Do not overfill cylinders. (No more than 80 % volume liquid
charge).
9. Do not exceed the maximum working pressure of the
cylinder, even temporarily.
10. When the cylinders have been filled correctly and the
process completed, make sure that the cylinders and the
equipment are removed from site promptly and all isolation
valves on the equipment are closed off.
11. Recovered refrigerant shall not be charged into another
refrigeration system unless it has been cleaned and
checked.
7.3.12 Labeling
Equipment shall be labeled stating that it has been de-
commissioned and emptied of refrigerant. The label shall be
dated and signed. For appliances containing flammable
refrigerants, ensure that there are labels on the equipment
stating the equipment contains flammable refrigerant.
7.3.13 Recovery
When removing refrigerant from a system, either for servicing