Switchgear designs

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ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
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Section 4. Switchgears and substations

Switchgear with voltage up to 1 kV AC and up to 1,5 kV DC. Switchgear designs

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Encyclopedia of radio electronics and electrical engineering / Rules for the installation of electrical installations (PUE)

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4.1.19. The designs of switchgear, low-voltage switchgears and equipment installed in them must comply with the requirements of current standards.

4.1.20. Switchgears and NKU must be designed so that vibrations arising from the operation of devices, as well as from shocks caused by external influences, do not disrupt contact connections and do not cause misalignment of devices and devices.

4.1.21. The surfaces of hygroscopic insulating boards on which non-insulated live parts are directly mounted must be protected from moisture penetration (by impregnation, painting, etc.)

In devices installed in damp and especially damp rooms and open installations, the use of hygroscopic insulating materials (for example, marble, asbestos cement) is not allowed.

4.1.22. The designs of the switchgear and NKU must provide for the entry of cables without violating the degree of protection of the shell, space for laying the cutting of external connections, as well as the shortest cable cutting length in this design. Access to all serviced devices, instruments, devices and their clamps must be provided. The switchgear must have devices for connecting zero working (N), grounding (PE) and combined (PEN) conductors of external cables and wires. In the case when external cables cannot be connected directly to the device terminals by cross-section or quantity, the switchgear design must provide additional terminals or intermediate busbars with devices for connecting external cables. Switchgears and NKU must provide for cable entry both from below and from above, or only from below or only from above.

See other articles Section Rules for the installation of electrical installations (PUE).

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