Sharp BU Series - Page 9

EN-7
ENGLISH
SAFETY PRECAUTIONS (Continued)
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 (optional for A2L). This
process shall be repeated until no refrigerant is within the system (optional for
A2L). When the nal oxygen-free nitrogen charge is used, the system shall be
vented down to atmospheric pressure to enable work to take place.
The outlet for the vacuum pump shall not be close to any potential ignition
sources, and ventilation shall be available.
• Charging procedures
In addition to conventional charging procedures, the following requirements shall
be followed.
a) Ensure that contamination of di󰀨erent 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.
b) Cylinders shall be kept in an appropriate position according to the instructions.
c) Ensure that the REFRIGERATING SYSTEM is earthed prior to charging the
system with refrigerant.
d) Label the system when charging is complete (if not already).
e) Extreme care shall be taken not to overll 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.
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;
– 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 cylinder is situated on the scales before recovery takes place.
g) Start the recovery machine and operate in accordance with instructions.
h) Do not overll cylinders (no more than 80 % volume liquid charge).