Duct Type Unit
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(2) That no live electrical components and wiring are exposed while charging,
recovering or purging the system.
(3) That there is continuity of earth bonding.
5.4.2 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 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 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.
5.4.3 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.
