Hitachi AIR CORE 700 PPIM-B18UFA1DQ Manuel D'utilisation, D'installation Et D'entretien page 9

Purging of the refrigerant circuit shall be achieved by breaking the vacuum in the system with inert gas
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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. The
system shall be vented down to atmospheric pressure to enable work to take place.
Ensure that the outlet of the vacuum pump is not close to any potential ignition sources and that
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ventilation is available.
In addition to conventional charging procedures, the following requirements shall be followed.
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○ 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 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 labelled).
○ Extreme care shall be taken not to overfill the refrigerating system.
Prior to recharging the system, it shall be pressure-tested with the appropriate purging gas. The system
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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.
Before carrying out the decommissioning procedure, it is essential that the technician is completely
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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:
(a) mechanical handling equipment is available, if required, for handling refrigerant cylinders;
(b) all personal protective equipment is available and being used correctly;
(c) the recovery process is supervised at all times by a competent person;
(d) 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 the cylinder is situated on the scales before recovery takes place.
○ Start the recovery machine and operate in accordance with instructions.
○ Do not overfill 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 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.
○ Recovered refrigerant shall not be charged into another refrigerating system unless it has been
cleaned and checked.
Equipment shall be labelled stating that it has been de-commissioned and emptied of refrigerant. The
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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.
When removing refrigerant from a system, either for servicing or decommissioning, it is required to
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follow good practice so that all refrigerants are removed safely.
When transferring refrigerant into cylinders, ensure that only appropriate refrigerant recovery cylinders
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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 shut-off 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
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equipment that is at hand and shall be suitable for the recovery of the flammable refrigerant. Consult
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