IM 1287-6 • REBEL APPLIED ROOFTOP 92 www.DaikinApplied.com
be according to instructions above.
Removal and evacuation
• When breaking into the refrigerant circuit to make repairs,
or for any other purpose, conventional procedures
shall be used. However, for ammable refrigerants
it is important that best practice be followed, since
ammability is a consideration.
• The following procedure shall be adhered to:
a. safely remove refrigerant following local and
national regulations
b. purge the circuit with inert gas
c. evacuate
d. purge with inert gas
e. open the circuit by cutting or brazing
• The refrigerant charge shall be recovered into the correct
recovery cylinders. For appliances containing ammable
refrigerants, the system shall be purged with oxygen-
free nitrogen to render the appliance safe for ammable
refrigerants. This process might need to be repeated
several times.
• Compressed air or oxygen shall not be used for purging
refrigerant systems.
• For appliances containing ammable refrigerants,
refrigerants purging shall be achieved by breaking the
vacuum in the system with oxygen-free nitrogen and
continuing to ll until the working pressure is achieved,
then venting to atmosphere, and nally pulling down to a
vacuum.
• When the nal oxygen-free nitrogen charge is used, the
system shall be vented down to atmospheric pressure to
enable work to take place.
• Ensure that the outlet for the vacuum pump is not close
to any potential ignition sources and that ventilation is
available.
Charging procedures
In addition to conventional charging
procedures, the following requirements shall be
followed.
• Ensure that contamination of dierent 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 in an appropriate position
according to the instructions.
• Ensure that the REFRIGERATING 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 overll the
REFRIGERATING 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.
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 recovered
refrigerant.
It is essential that electrical power is available
before the task is commenced.
• Become familiar with the equipment and its operation.
• Isolate system electrically.
• 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.
• Pump down refrigerant system, if possible.
• If a vacuum is not possible, make a manifold so that
refrigerant can be removed from various parts of the
system.
• Make sure that cylinder is situated on the scales before
recovery takes place.
• Start the recovery machine and operate in accordance
with instructions.
• Do not overll cylinders (no more than 80 % volume liquid
charge).
• Do not exceed the maximum working pressure of the
cylinder, even temporarily.
• When the cylinders have been lled 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 o.
• Recovered refrigerant shall not be charged into another
REFRIGERATING SYSTEM unless it has been cleaned
and checked.
Labelling
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
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