any possibility of sparks;
- Verification that no live electrical components or wiring are exposed during charging,
recovery or purging of the system;
- verification that there is continuity of the equipotential bonding to earth.
- Repairs of hermetic components
During repairs of hermetic components, all power supplies must be disconnected from the
equipment undergoing operations before any removal of hermetic covers, etc. If it is
absolutely necessary to supply the equipment with electricity during service operations, a
continuously operating leak detection device must be located at the most critical point to
give warning in case of a potentially dangerous situation.
Particular attention should be paid to the following to ensure that when working on
electrical components, the enclosure is not altered in a way that alters the level of
protection. This should include damage to cables, excessive number of connections,
terminals that do not meet the original specification, damage to seals, incorrect
adjustment of cable entries, etc.
Make sure that the unit is mounted safely.
Ensure that the joints or sealing materials have not degraded to the point of no longer
preventing the penetration of flammable atmospheres. Spare parts must comply with the
manufacturer's specifications,
NOTE: The use of a silicone sealant can inhibit the effectiveness of certain types of leak
detection equipment. Intrinsically safe components do not have to be isolated before
undergoing a procedure
- Repair of intrinsically safe components
Do not apply inductive loads or permanent capacities to the circuit without ensuring that it
will not exceed the permissible voltage and current allowed for the equipment used.
Intrinsically safe components are the only types that can be worked on when they are
energised in a flammable atmosphere. The test equipment must have the correct rated
characteristics.
Replace components only with parts specified by the manufacturer. Other parts can cause
the refrigerant to ignite in the atmosphere as a result of a leak.
- Cabling
Check that the wiring will not be subjected to wear, corrosion, excessive pressure,
vibration, sharp edges or any other adverse environmental effects. The verification must
also take into account the effects of aging or continuous vibration from sources such as
compressors or fans.
- Detection of flammable refrigerants
Under no circumstances should potential ignition sources be used to search for or detect
refrigerant leaks. A haloid lamp (or any other detector using an open flame) must not be
used.
