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 no live electrical components and wiring are exposed
while charging, recovering or purging the system; that there is continuity of earth bonding.
7.Sealed electrical components shall be replaced.
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.
Check for 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. Intrinsically safe components must be replaced.
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, 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.
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 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. If a leak is suspected, all naked flames shall be removed/
extinguished.
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