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8
Repairs to sealed components
During repairs to sealed components, all electrical supplies shall be disconnected
from the equipment being worked upon prior to any removal of sealed covers, etc. If it
is absonecessary to have an electrical supply to equipment during servicing, then a
permoperating form of leak detection shall be located at the most critical point lutely
anently to warn of a potentially hazardous situation.
Particular attention shall be paid to the following to ensure that by working on electri-
cal 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, termi-
nals not made to original specification, damage to seals, incorrect fitting of glands, etc.
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 flammable atmosphere. The test apparatus shall be at the correct
rating.
Replace components only with parts specified by the manufacturer. Other parts may
result in the ignition of refrigerant in the atmosphere from a leak.
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 com-
pressors or fans.
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.
Leak detection methods
The following leak detection methods are deemed acceptable for all refrigerant sys-
tems.
Electronic leak detectors may be used to detect refrigerant leaks but, in the case of
flammable refrigerants, the sensitivity may not be adequate, or may need re-calibra-
Replacement parts shall be in accordance with the manufacturer's specifications.
NOTE : The use of silicon sealant can inhibit the effectiveness of some types of leak
detection equipment. Intrinsically safe components do not have to be isolated prior to
working on them.
Ensure that the apparatus is mounted securely.
Ensure that seals or sealing materials have not degraded to the point that they no
longer serve the purpose of preventing the ingress of flammable atmospheres.
Specialist's Manual
