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● that no live electrical components and wiring are exposed while charging, recovering or
purging the system;
● that there is continuity of earth bonding.
10. Repairs to sealed components
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.
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 the apparatus is mounted securely.
Ensure that seals or sealing materials have not degraded to the point 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.
11. 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.
12. 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.
13. 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.
14. Removal and evacuation
When breaking into the refrigerant circuit to make repairs – or for any other purpose –
conventional procedures shall be used. However, for flammable refrigerants it is important
that best practice is followed since flammability is a consideration. The following procedure
shall be adhered to:
● remove refrigerant;
● purge the circuit with inert gas;
● evacuate;
● purge with inert gas;
● open the circuit by cutting or brazing.
