Panasonic CS-VU9SKQ Instrucciones De Operación página 8

Safety precautions
4. Repair to intrinsically safe components
• Do not apply any permanent inductive or
capacitance loads to the circuit without
ensuring that this will not exceed the
permissible voltage and current permitted for
the equipment in use.
• Intrinsically safe components are the only
types that can be worked on while live in the
presence of a fl ammable atmosphere.
• The test apparatus shall be at the correct
rating.
• Replace components only with parts specifi ed
by the manufacturer. Unspecifi ed parts by
manufacturer may result ignition of refrigerant
in the atmosphere from a leak.
5. Cabling
• Check that cabling will not be subject to wear,
corrosion, excessive pressure, vibration, sharp
edges or any other adverse environmental
effects.
• The check shall also take into account the
effects of aging or continual vibration from
sources such as compressors or fans.
6. Detection of fl ammable refrigerants
• Under no circumstances shall potential sources
of ignition be used in the searching or detection
of refrigerant leaks.
• A halide torch (or any other detector using a
naked fl ame) shall not be used.
7. Leak detection methods
• Electronic leak detectors shall be used
to detect fl ammable refrigerants, but the
sensitivity may not be adequate, or may need
re-calibration.
(Detection equipment shall be calibrated in a
refrigerant-free area.)
• Ensure that the detector is not a potential
source of ignition and is suitable for the
refrigerant used.
• Leak detection equipment shall be set at a
percentage of the LFL of the refrigerant and
shall be calibrated to the refrigerant employed
and the appropriate percentage of gas (25 %
maximum) is confi rmed.
• Leak detection fl uids 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 pipe-work.
• If a leak is suspected, all naked fl ames shall be
removed/extinguished.
• If 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.
8
8. 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 fl ammability 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 "fl ushed" 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 fi ll until the working pressure is achieved,
then venting to atmosphere, and fi nally pulling
down to a vacuum.
• This process shall be repeated until no
refrigerant is within the system.
• When the fi nal 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 pipe work are to take place.
• Ensure that the outlet for the vacuum pump is
not close to any ignition sources and there is
ventilation available.
9. 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
minimize 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 over fi ll the
refrigeration system.
• Prior to recharging the system it shall be
pressure tested with OFN (refer to #7).
• 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.