Electrolux EACM-09 CG/N6 User Manual page 7

situation.
• Particular attention shall be paid to the
following to ensure that by working on elec-
trical components, the casing is not altered
in such a way that the level of protection
is affected. This shall include damage to
cables, excessive number of connections,
terminals not made to original specifica-
tion, damage to seals, incorrect fitting of
glands, etc. Ensure that apparatus is mount-
ed securely. Ensure that seals or sealing
materials have not degraded such that they
no longer serve the purpose of preventing
the ingress of flammable atmospheres.
Replacement parts shall be in accordance
with the manufacturer's specifications.
NOTE: The use of silicon sealant may inhibit
the effectiveness of some types of leak
detection equipment. Intrinsically safe com-
ponents do not have to be isolated prior to
working on them.
8. 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 permis-
sible voltage and current permitted for the
equipment in use. Intrinsically safe compo-
nents are the only types that can be worked
on while live in the presence of a flammable
atmosphere. The test apparatus shall be
at the correct rating. Replace components
only with parts specified by the manufactur-
er. Other parts may result in the ignition of
refrigerant in the atmosphere from a leak.
9. Cabling
Check that cabling will not be subject to
wear, corrosion, excessive pressure, vibra-
tion, 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.
10. Detection of flammable refrigerants
Under no circumstances shall potential
sources of ignition be used in the searching
for or detection of refrigerant leaks. A halide
torch (or any other detector using a naked
flame) shall not be used.
11. Leak detection methods
The following leak detection methods are
deemed acceptable for systems contain-
ing flammable refrigerants. Electronic leak
detectors shall be used to detect flamma-
ble 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
Air conditioner portable
detector is not a potential source of igni-
tion 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 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 pipe-work. If a
leak is suspected, all naked flames 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 braz-
ing process.
12. 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 consid-
eration. 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 refrig-
erant 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
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.
13. Charging procedures
In addition to conventional charging pro-
cedures, the following requirements shall be
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