Nordic Home AC-511 Bedienungsanleitung Seite 38

not be used for this task.
Flushing must be achieved by breaking the vacuum in the system using OFN and continuing to fill until the working
pressure is achieved, then venting to the atmosphere, and finally reducing to a vacuum pressure. This process
must be repeated until there is no refrigerant left in the system. When the final OFN charge is used, the system
must be ventilated to atmospheric pressure to enable work to take place. This operation is absolutely vital if brazing
operations are to take place on the pipework.
Ensure that the power socket for the vacuum pump is not close to any ignition sources and that there is ventilation
available.
13. Charging procedures
In addition to conventional charging procedures, the following requirements must be met.
– Ensure that there is no contamination of different refrigerants when using charging equipment. Hoses or lines
must be as short as possible to minimise the amount of refrigerant contained in them.
– Cylinders must be kept upright.
– Ensure that the refrigeration system is earthed prior to charging the system with refrigerant.
– Label the system when charging is complete (unless it is already labelled).
– Extreme care must be taken not to overfill the refrigeration system.
The system must be pressure-tested using OFN prior to recharging. The system must be tested for leaks on com-
pletion of charging but prior to commissioning. A follow-up leak test must be carried out prior to leaving the site.
14. Decommissioning
Before carrying out this procedure, it is essential that the technician is completely familiar with the equipment and
all its details. It is recommended good practice that all refrigerants are recovered safely. Prior to the task being
carried out, an oil and refrigerant sample must be taken in case analysis is required prior to reuse of reclaimed
refrigerant. It is essential that electricity is available before starting the task.
a) Familiarise yourself with the equipment and its operation.
b) Isolate the system electrically.
c) Before attempting the procedure ensure that:
• Mechanical 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.
d) Pump down refrigerant system, if possible.
e) If a vacuum is not possible, make a manifold so that refrigerant can be removed from various parts of the
system.
f) Make sure that the cylinder is placed on the scales before recovery takes place.
g) Start the recovery machine and operate in accordance with manufacturer's instructions.
h) Do not overfill cylinders. (No more than 80 % liquid charge by volume).
i) Do not exceed the maximum working pressure of the cylinder, even temporarily.
j) When the cylinders have been filled correctly and the process completed, make sure that the cylinders and the
equipment are removed from the site promptly and that all isolation valves on the equipment are closed off.
k) Recovered refrigerant must not be charged into another refrigeration system unless it has been cleaned and
checked.
15. Labelling
Equipment must be labelled stating that it has been decommissioned and emptied of refrigerant. The label must
be dated and signed. Ensure that there are labels on the equipment stating the equipment contains flammable
refrigerant.
16. Recovery
When removing refrigerant from a system, either for servicing or decommissioning, ensuring that all refrigerants are
removed safely is recommended good practice.
When transferring refrigerant into cylinders, ensure that only appropriate refrigerant recovery cylinders are used.
Ensure that the correct number of cylinders for holding the total system charge are available. All cylinders to be
used must be designated for the recovered refrigerant and labelled for that refrigerant (i.e. special cylinders for the
recovery of refrigerant). Cylinders must be complete with pressure relief valves and associated shut-off valves in
good working order. Empty recovery cylinders are evacuated and, if possible, cooled before recovery occurs.
The recovery equipment must be in good working order with instructions concerning the equipment being used and
must be suitable for the recovery of flammable refrigerants. A set of calibrated weighing scales must also be availa-
ble and in good working order. Hoses must be complete with leak-free disconnect couplings and in good condition.
Before using the recovery machine, check that it is in satisfactory working order, has been properly maintained and
that any associated electrical components are sealed to prevent ignition in the event of a refrigerant release. If in
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