IEEE C37.20.1-1987 pdf free.IEEE Standard for Metal-Enclosed Low-Voltage Power Circuit-Breaker Switchgear.
IEEE C37.20.1 The definitions of terms contained in this stan-dard, or in other standards referred to in thisstandard, are not intended to embrace all legitimate meanings of the terms. They are applicable only to the subject treated in this standard.Ilf a term is not defined in this standard, thedefinition in ANSI /IEEE C37.100-1981[12applies. An asterisk () following a definition indicates that the definition in this standard isnot contained in ANSI/IEEE C37.100-1981[12]while a dagger (t) indicates the definition differsfrom that in ANSI /1EEE C37.100-1981[12] switchgear.Ageneral term coveringswitching and interrupting devices and theircombination with associated control，instruments, metering, protective and regulating de-vices,also assemblies of these devices withassociated interconnections,accessories,andsupporting structures used primarily in connec-tion with the generation,transmission，distri-bution, and conversion of electric power.
switchgear assembly (see Fig A).An assembled equipment (indoor or outdoor) including,but not limited to，one or more of thefollowing categories: switching,interrupting,control,instrumentation，metering，protectiveand regulating devices, together with their sup-porting structures, enclosures,conductors, elec-trical interconnections,and accessories.
metalenclosed power switchgear. Aswitchgear assembly completely enclosed on allsides and top with sheet metal (except for ventilating openings and inspection windows) containing primarypower-circuit switching orinterrupting devices，or both，with buses andconnections. The assembly may include controland auxiliary devices. Access to the interior ofthe enclosure is provided by doors or removablecovers, or both.IEEE C37.20.1 pdf download.