89
User manual
Room air conditioner - IMOTO X
EN
APPENDIX FOR REFRIGERANT R290/R32
refrigerant employed and the appropriate percentage of gas (25 % maximum} is confirmed.
Leak detection fluids are suitable for use with most refrigerants but the use of detergents containing chlorine
shall be avoided as the chlorine may react with the refrigerant and corrode the copper pipework.
lf a leak is suspected, all open flames shall be removed/extinguished.
lf 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. Oxygen free
nitrogen (OFN) shall then be purged through the system both before and during the brazing process.
7. REMOVAL AND EVACUATION
When breaking into the refrigerant circuit to make repairs - or for any other purpose - conventional procedures
shall be used. However, 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. 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 this task. 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 pipework are to take place. Ensure that
the outlet tor the vacuum pump is not close to any ignition sources and !here is ventilation available.
8. 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 minimise 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 OFN. 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.
9. DECOMMISSIONING
Before carrying out this procedure, it is essential that the technician is completely familiar with the equipment
and all its detail. lt 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. lt is essential that 4 GB electrical power is available before the task is commenced.
a. Become familiar with the equipment and its operation.
b. lsolate system electrically.
c. Before attempting the procedure ensure that: mechanical handling equipment is available, if required, for
handling refrigerant cylinders;
d. All personal protective equipment is available and being used correctly; the recovery process is supervised
at all times by a competent person;
e. recovery equipment and cylinders conform to the appropriate standards.
f. Pump down refrigerant system, if possible.
g. lf a vacuum is not possible, make a manifold so that refrigerant can be removed from various parts of the
