IEEE C37.122-2010 pdf free download.IEEE Standard for High Voltage Gas-Insulated Substations Rated Above 52 kV
. Definitions For the purposes of this standard, the following terms and definitions apply. IEEE Std C37.100 should be referenced for terms not defined in this clause. For terms that are not listed in IEEE Std C37.100 users should refer to The IEEE Standards Dictionary: Glossary of Terms & Definitions. 8 alarm pressure p ae (or density ? ae ): For insulation and/or switching pressure (Pa), referred to the standard atmospheric air conditions of +20 °C and 101.3 kPa (or density), which may be expressed in relative or absolute terms, at which a monitoring signal may be provided. bus-charging current (rated): Current expressed as steady-state rms value which a disconnect switch is capable of switching when energizing or de-energizing parts of a bus system or similar capacitive loads. bus-transfer current: The current that flows in a disconnect switch when it transfers load from one bus system to another. bus-transfer voltage: The power-frequency voltage across the open disconnect switch gap after breaking or before making the bus-transfer current. class A grounding switch: A grounding switch designated to be used in circuits having relatively short sections of line or low coupling to adjacent energized circuits. class B grounding switch: A grounding switch designated to be used in circuits having relatively long lines or high coupling to adjacent energized circuits. compartment (GIS): A section of a gas-insulated switchgear assembly that is enclosed except for openings necessary for interconnection providing insulating gas isolation from other compartments. A compartment may be designated by the main components in it, e.g., circuit breaker compartment, disconnect switch compartment, bus compartment, etc.
design pressure of enclosures: The maximum gas pressure to which a gas-insulated switchgear enclosure will be subjected under normal service conditions, including the heating effects of rated continuous current. electromagnetically induced current (grounding switch): The inductive current that a grounding switch is capable of switching when it connects to and disconnects from ground one termination of a de- energized transmission line, with the other termination grounded, and with an energized line carrying current in parallel with, and in proximity to, the grounded line. electrostatically induced current (grounding switch): The capacitive current that a grounding switch is capable of switching when it connects to or disconnects from ground one termination of a de-energized transmission line, with the other termination open, and with an energized line in parallel with, and in proximity to, the grounded line. gas monitoring systems: Any instrumentation for measuring, indicating, or giving remote warning of the condition or change in condition of the gas in the enclosure, such as pressure, density, moisture content, etc. gas-insulated switchgear (GIS): A compact, multi-component assembly, enclosed in a grounded metallic housing in which the primary insulating medium is SF 6 and which normally includes buses, switches, circuit breakers, and other associated equipment. gas-insulated switchgear enclosure: A grounded part of gas-insulated metal-enclosed switchgear assembly retaining the insulating gas under the prescribed conditions necessary to maintain the required insulation level, protecting the equipment against external influences and providing a high degree of protection from approach to live energized parts. gas-insulated switchgear enclosure currents: Currents that result from the voltages induced in the metallic enclosure by effects of currents flowing in the enclosed conductors. gas leakage rate (absolute): Amount of gas escaped by time unit expressed in units Pa × m 3 /s. gas leakage
gas pass through insulator: An internal insulator supporting one or more conductors specifically designed to allow the passage of gas between adjoining compartments. gas zone: A section of the GIS which may consist of one or several gas compartments which have a common gas monitoring system. The enclosure can be single-phase or three-phase. local control cubicle (or cabinet) (LCC): Cubicle or cabinet typically containing secondary equipment including control and interlocking, measuring, indicating, alarm, annunciation, and mimic one-line diagram associated with the primary equipment. It may also include protective relays if specified by the user. minimum functional pressure p me (or density ? me ): Insulation and/or switching pressure (in Pa), at and above which rated characteristics of switchgear are maintained. It is referred to at the standard atmospheric air conditions of +20 °C and 101.3 kPa (or density) and may be expressed in relative or absolute terms. partition: Part of an assembly separating one compartment from other compartments. It provides gas isolation and support for the conductor (gas barrier insulator).