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materials which are inherently resistant to being corroded or are suitably protected against being so corroded.
9) Checks to electrical devices
Repair and maintenance to electrical components shall include initial safety checks and component inspection
procedures. If a fault exists that could compromise safety, then no electrical supply shall be connected to the
circuit until it is satisfactorily dealt with. If the fault cannot be corrected immediately but it is necessary to
continue operation, an adequate temporary solution shall be used. This shall be reported to the owner of the
equipment so all parties are advised. Initial safety checks shall include:
• That capacitors are discharged: this shall be done in a safe manner to avoid possibility of sparking;
• That there no live electrical components and wiring are exposed while charging, recovering or purging the
system;
• That there is continuity of earth bonding.
2. Repairs to sealed components
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) 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 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
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