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IMPORTANT INSTRUCTIONS
Initial safety checks shall include:
that capacitors are discharged: this shall be done in a safe manner to avoid possibility of sparking;
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that no live electrical components and wiring are exposed while charging, recovering or purging the system;
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that there is continuity of earth bonding.
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Repairs to sealed components
During repairs to sealed components, all electrical supplies shall be disconnected from the equipment being
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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.
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Particular attention shall be paid to the following to ensure that by working on electrical.
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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 the apparatus is mounted securely.
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Ensure that seals or sealing materials have not degraded to the point that they no longer serve the purpose of
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preventing the ingress of flammable atmospheres. Replacement parts shall be in accordance with the
manufacturer's specifications.
Repair to intrinsically safe components
Do not apply any permanent inductive or capacitance loads to the circuit without ensuring that this will not
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exceed the permissible voltage and current permitted for the equipment in use.
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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
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refrigerant in the atmosphere from a leak.
NOTE The use of silicon sealant can inhibit the effectiveness of some types of leak detection equipment.
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Intrinsically safe components do not have to be isolated prior to working on them.
Cabling
Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any
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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.
Detection of flammable refrigerants
Under no circumstances shall potential sources of ignition be used in the searching for or detection of
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refrigerant leaks. A halide torch (or any other detector using a naked flame) shall not be used.
The following leak detection methods are deemed acceptable for all refrigerant systems.
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Electronic leak detectors may be used to detect refrigerant leaks but, in the case of FLAMMABLE
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REFRIGERANTS, 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.
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Leak detection fluids are also suitable for use with most refrigerants but the use of detergents containing
chlorine shall be avoided as the chlorine may react with the refrigerant and corrode the copper pipe-work.
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