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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 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
