7.Repairs to sealed components
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 afected.
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 specifica-
tions.
NOTE: The use of silicon sealant may inhibit the e ectiveness 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,
vibration, sharp edges or any other adverse environmental efects. The check shall
also take into account the e ects 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 search-
ing 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 con-
taining flammable refrigerants. Electronic leak detectors shall be used to detect
flammable refrigerants, but the sensitivity may not be adequate, or may need
re-calibration.
08