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GB
power supply is to must be connected to the circuit until the matter has been rectified. If the
fault cannot be corrected immediately but continuing operation is necessary, an adequate
temporary solution must be employed. This must be reported to the owner of the equipment
so that all parties are advised.
Initial safety checks must include:
Discharge of capacitors: this must be done safely manner to prevent sparking;
Ensuring that no live electrical components or wiring are exposed while charging,
recovering or purging the system;
That there is continuity of earth bonding.
• Repairs to sealed components
1 )When repairing sealed components, all power supplies must be disconnected from the
equipment being worked on prior to removal of any sealed covers, etc. If it is absolutely
necessary to maintain a power supply to equipment during servicing, a permanently
operating form of leak detection must be located at the most critical point so as to provide
prior warning of any potentially hazardous situation.
2) Particular attention must be paid to the following so as to ensure that working on
electrical components does not result in alteration of the casing in such a way that the
level of protection is affected. This must include damage to cables, excessive numbers of
connections, terminals not made to the original specification, damage to seals, incorrect
fitting of glands, etc.
Ensure that the apparatus is mounted securely.
Ensure that seals or sealants have not degraded such that they no longer prevent the
ingress of flammable atmospheres. Replacement parts must 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.
• Repairing 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 must be at the correct rating.
Components must only be replaced with parts specified by the manufacturer. Other parts
may result in the ignition of leaked refrigerant in the atmosphere.
• Cabling
Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration,
sharp edges or any other adverse environmental impact. The check must also take into
account the effects of ageing or constant vibration from sources such as compressors or
fans.
• Detection of flammable refrigerants
Under no circumstances should potential sources of ignition be used when searching for or
detecting refrigerant leaks. Halide torches (or any other detectors that use naked flames)
must not be used.
• Leak detection methods
The following leak detection methods are deemed acceptable for systems containing
flammable refrigerants. Electronic leak detectors may be used to detect flammable
refrigerants, but their sensitivity may be inadequate or they may need re-calibration.
(Detection equipment must be calibrated a refrigerant-free area.) Ensure that the detector
is not a potential source of ignition and is suitable for the refrigerant used. Leak detection
