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purging the system;
---That there is continuity of earth bonding.
Repairs to sealed components
Ensure that the apparatus is mounted securely.
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 abso-
lutely
necessary to have an electrical supply to equipment during servicing, then a perm-
anently
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 follow
ing 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.
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.
Cabling
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.
NOTE : The use of silicon sealant can inhibit the effectiveness of some types of leak
detection equipment. Intrinsically safe components do not have to be isolated prior to
working on them.
Repair to intrinsically safe components
Int
rinsically safe componen
ts 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.
Detection of flammable refrigerants
Replace components only with parts specified by the manufacturer. Other parts may
result in the ignition of refrigerant in the atmosphere from a leak.
Leak detection methods
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.
Check that cabling will not be subject to wear, corrosion, ex
cessive 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 source
s such as
compressors or fans.
The following leak detection methods are deemed acceptable for all refrigerant systems.
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