IEEE C37.21-2017 pdf free.IEEE Standard for Control Switchboards.
For the purposes of this document, the following terms and definitions apply. The IEEE Standards Dictionary Online should be consulted for terms not defined in this clause.
The definitions of tenns contained in this standard, or in other standards referred to in this standard, are not intended to embrace all legitimate meanings of the terms. They arc applicable only to the subject treated in this standard.
bcnchboard: A combination of a control desk and a vertical switchboard in a common assembly. See also:
dual benchhoard and duplex henchhoard.
control desk (console): A control switchboard consisting of one or more relatively short horizontal or inclined panels mounted on an assembly of such a height that the panel-mounted devices are within convenient reach of an attendant.
control switch boa rd: A type of switchboard including control, instrumentation, metering, protective (relays), or regulating equipment for remotely controlling other equipment. Control switchboards do not include the primary power-switching devices or their connections.
dead-front switchboard: A switchboard that has no exposed live parts on the front.
dual henchhoard: A combination assembly of a henchboard and a vertical hinged panel switchboard placed back to back (no aisle) and enclosed with a top and ends. Sec also: benchboard and duplex benchboard.
dual switchboard: A control switchboard with front and rear panels separated by a comparatively short distance (no aisle) and enclosed at both ends and top. The panels on at least one side are hinged for access to the panel wiring. See also: duplex switchboard.
duplex benchboard: A combination assembly of a bcnchboard and vertical switchboard placed back-to-back and enclosed with a top and ends (not grille). Access space (aisle) with entry doors is provided between the benchboard and vertical switchboard. See also: henchboard and dual heiichboard.
duplex switchboard: A control switchboard consisting olpanels placed back-to-back and enclosed with a top and ends (not gnlLe). Access space (aisle) with entry doors is provided between the rows of panels. Sec also:dual switchboard.
enclosed switchboard: A type of switchgear assembly that consists of one or more panels with electric devices mounted thereon, and associated framework.
fixed rack (cabinet): An assembly enclosed at the top and sides, either open or with door(s) for access, with a top-to-bottom front panel opening for equipment mounting [for example, 486 mm (19 in) wide chassis and subpancl assemblies]. See also: swing rack cabinet.
swing rack cabinet: An assembly enclosed at the top, sides, and rear with front hinged door for front access having a swing open frame for equipment mounting [for exaniple, 486 mm (19 in) wide chassis in subpancl assemblies]. See also: fixed rack (cabinet).
vertical switchboard: A control switchboard composed only of vertical panels. Sec also: vertical enclosed switchboard and vertical open switchboard.
NOTE — This typc of switchboard may bc enclosed or have an open back.
vertical enclosed switchboard: A dead-front switchboard that has an overall sheet metal enclosure (not grille) covering back, top. and ends of the entire assembly. See also: vertical open switchboard and vertical switchboard.IEEE C37.21 pdf download.