IEEE C37.20.9:2019 pdf free download – IEEE Standard for Metal-EnclosedSwitchgear Rated 1 kV to 52 kV Incorporating Gas Insulating Systems
design tests: Tests made by the manufacturer to determine the adequacy of the design of a particular type,style, or model of equipment or its component parts to meet its assigned ratings and to operate satisfactorilyunder normal service conditions or under special conditions, if specified, and that may be used to demonstratecompliance with applicable standards of the industry.
NOTE—Design tests are somctimes called “type tests.”
disconnecting switch (or isolating switch): A mechanical switching device used for changing the connectionsin a circuit, or for isolating a circuit or an equipment from the source of power. It is required to carry normalload current continuously, as well as abnormal or short-circuit currents for short intervals as specified. It isalso required to open or close circuits either when negligible current is broken or madec, or when no significantchange in the voltage across the terminals of each of the switch poles occurs.
drawout element (device): A(disconnecting) device in which the removable portion may be removed fromthe stationary portion without the necessity of unbolting connections or mounting supports. It contains high-voltage components and coordinates with all safety interlocking functions.
NOTE—The drawout element is similar to the definition of a “removable element”in IEEE Std C37.20.2 andIEEE Std C37.20.10.
encapsulate: The process by which a solid dielectric insulating material is bonded to a live (energized)part or the live part is embedded in the insulating material with the exception of the electrical connections.The process is a molding process and excludes all other means of adhesion such as painting or dipping.Theinsulation material may or may not provide mechanical support for the live parts.Encapsulated solid dielectricinsulation is used in this standard.
field tests: Tests made after the assembly has been installed at its place of utilization.
gas compartment: See: compartment of metal-enclosed, gas-insulated switchgear(MEGIS).
gas-insulated switchgear(GIS): A multicomponent assembly, enclosed in a grounded metallic housing inwhich the primary insulating medium is (typically)SF, and which normally includes buses, switches, circuitbreakers, and other associated equipment.
gas leakage:The leakage rate is the amount of gas that escapes related to the total amount(mass or volume)ofgas in each compartment at rated filling pressure(or density). lt is expressed in percentage per year.
gas monitoring system: Any instrumentation for measuring,indicating, or giving remote warning of thecondition or change in condition of the gas in the enclosure, such as pressure, density, or moisture content.
grounding switch: A mechanical switching device by means of which a circuit or a piece of apparatus may beclectrically connected to ground.
interrupter compartment: The portion of the switchgear assembly that contains one interrupting device(such as an interrupter switch,fuse interrupter switch combination, a drawout circuit breaker, or stationarycircuit breaker) and the associated primary conductors.
isolated phase: A construction in which each phase conductor is enclosed by an individual metal housingseparated from adjacent conductor housings by an air or a gas space.
metal-enclosed, gas-insulated switchgear (MEGIS): A switchgear assembly completely enclosed on allsides and top with metal. At least one compartment is usually filled with gas (typically SF.) although othergases are permitted at a higher than ambient pressure as an insulating medium.The switchgear may or may notcontain additional internal metal compartments.