Switchgear assemblies wiring

The rating of cuiTcnt-carrying equipment (switchgear assemblies, such as for the main bus system), devices (breakers, switches and contactors) and components (connecting links and wiring etc.) is defined by two parameters ... 

The mechanical endurance of the current-carrying parts of all the equipment, bus system, deviees and components, used in a particular circuit as well as the load-bearing members and supports on which they are mounted. The electrical parts of a device (breakers and switches, etc.) are the responsibility of the component manufacturers. The manufacturer of the switchgear assembly is responsible for the busbar systems, metallic links and wires. 

The bus system of a switchgear assembly, its interconnecting links and wires are the protected type components, whereas an interrupter (breaker, switch or a fuse) may be a protecting or protected type, depending upon their application and location in the circuit. A contactor and an OCR are therefore protected devices in the same context, for they provide no short-time protection. A protecting device may become protected when it is also provided with a back-up protection. 

This test is applicable to all outdoor metal-enclosed switchgear and controlgear assemblies, as in lEC 60298, lEC 60694 and ANSI C-37/20C. The enclosure to be tested should be complete in all respects including its mounts, bushings (for HT switchgear assemblies, 1 kV and above) and wiring. One or more vertical units can be tested simultaneously as may be convenient, but not more than 3 m panel width can be tested at a time. For a multiple unit switchboard, however, at least two vertical units should be tested together to check the joints between the units. 

The 3rd Amendment to the lET Wiring Regulations has introduced Regulation 421.1.200 requiring switchgear assemblies, including consumer unit enclosures, to be ... 

Installations prone to heavy vibrations and shocks stich as on the mounting platform near a laige power-generating unit, on a ship, locomotive and similar installations may require provisions to absorb shocks and dampen vibrations to prevent loosening of components and wire connections in a switchgear or a controlgear assembly. Some economical methods to achieve this can be by providing ... 

Rigidity of doors, bus and wiring systems etc. in a switchgear or controlgear assembly. 

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