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and wiring are exposed while charging, recovering or purging the system; that there is
continuity of earth bonding.
2 REPAIRS TO SEALED COMPONENTS
2.1 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 absolutely necessary to have an electrical supply to equipment during servicing,
then a permanently operating form of leak detection shall be located at the most
critical point to warn of a potentially hazardous situation.
2.2 Particular attention shall be paid to the following to ensure that by working on
electrical
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 specification, damage to seals, incorrect fitting of glands, etc. Ensure
that apparatus is mounted 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 components do not have to be isolated prior to working
on them.
3 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.
4 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.
5 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.
6 LEAK DETECTION METHODS
The following leak detection methods are deemed acceptable for systems containing
flammable refrigerants. Electronic leak detectors shall be used to detect flammable
refrigerants, but the sensitivity may not be adequate, or may need recalibration.
(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
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