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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.
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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.
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 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.
9. Cabling
Check that cabling will not be subject to wear, corrosion, excessive pressure,
SAFETY OPERATION OF FLAMMABLE REFRIGERANT
extinguished. If a leakage of refrigerant is found which requires brazing, all of the
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.
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
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 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 the
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/