Mark HCNI 533, Техническое руководство

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7
EN
Checks to electrical devices
• Repair and maintenance to electrical components shall include initial safety checks and component
inspection procedures.
If a fault exists that could compromise safety, then no electrical supply shall be connected to the
circuit until it is satisfactorily dealt with.
If the fault cannot be corrected immediately but it is necessary to continue operation, an adequate
temporary solution shall be used. This shall be reported to the owner of the equipment so all parties
are advised.
Initial safety checks shall include:
- That capacitors are discharged: this shall be done in a safe manner to avoid possibility
of sparking.
- That there no live electrical components and wiring are exposed while charging,
recovering or purging the system.
- That there is continuity of earth bonding.
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 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.
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.
Repair to intrinsically safe components
• 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.
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.
Leak detection methods
• The following leak detection methods are deemed acceptable for systems containing flammable
refrigerants.
Electronic leak detectors shall be used to detect flammable refrigerants, but the sensitivity may not