to live energized parts.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.Partition: Part of an assembly separating one compartment from other compartments. It provides gas isolation and support for the conductor (gas barrier insulator).Power kinematic chain: Mechanical connecting system from and including the operating mechanism up to and including the moving contacts.
In IEC 62271‐203, GIS is defined as follows:Metal‐enclosed switchgear and controlgear: switchgear and controlgear assemblies with an external metal enclosure intended to be earthed, and complete except for external connections.Gas‐insulated metal‐enclosed switchgear: metal‐enclosed switchgear in which the insulation is obtained, at least partly, by an insulating gas other than air at atmospheric pressure.Gas‐insulated switchgear enclosure: part of gas‐insulated metal‐enclosed switchgear retaining the insulating gas under the pre‐scribed conditions necessary to maintain safely the highest insulation level, protecting the equipment against external influences and providing a high degree of protection to personnel.Compartment: part of gas‐insulated metal‐enclosed switchgear, totally enclosed, except for openings necessary for interconnection and control.Support insulator: internal insulator supporting one or more conductors.Partition: support insulator of gas‐insulated metal‐enclosed switchgear separating one compartment from other compartments.
Note 1 to entry: A compartment may be designated by the main component contained therein, e.g., circuit‐breaker compartment, bus bar compartment.
1.2.2 Gas‐Insulated Metal‐Enclosed Switchgear
Metal‐enclosed switchgear in which the insulation is obtained, at least partly, by an insulating gas other than air at atmospheric pressure, as defined in IEC 62271‐203. This term generally applies to high‐voltage switchgear and controlgear. Three‐phase enclosed gas‐insulated switchgear applies to switchgear with the three phases enclosed in a common enclosure.
Single‐phase enclosed gas‐insulated switchgear applies to switchgear with each phase enclosed in a single independent enclosure.
1.2.3 Compartment of GIS
A section of a gas‐insulated switchgear assembly that is enclosed except for openings necessary for interconnection provides insulating gas isolation from other compartments. A compartment may be designated by the main components in it, for example, circuit breaker compartment, disconnect switch compartment, bus compartment, and so on, as defined in IEEE C37.122.
A compartment of GIS as defined in IEC 62271‐203 as part of a gas‐insulated metal‐enclosed switchgear is totally enclosed, except for openings necessary for interconnection and control.
A compartment may be designated by the main component contained therein, for example, circuit breaker compartment or bus bar compartment.
1.2.4 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, as defined in IEEE C37.122.
1.2.5 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., as defined in IEEE C37.122.
1.2.6 Gas Leakage Rate (Absolute)
The amount of gas escaping by a time unit expressed in units of Pa m3/s, as defined in IEEE C37.122.
1.2.7 Gas Leakage Rate (Relative)
The absolute leakage rate related to the total amount (mass or volume) of gas in each compartment at the rated filling pressure (or density). It is expressed in percentage per year, as defined in IEEE C37.122.
1.2.8 Gas Pass Through Insulator
An internal insulator supporting one or more conductors specifically designed to allow the passage of gas between adjoining compartments, as defined in IEEE C37.122.
1.2.9 Gas Zone
A section of the GIS, which may consist of one or several gas compartments that have a common gas monitoring system. The enclosure can be single‐phase or three‐phase, as defined in IEEE C37.122.
1.2.10 Local Control Cubicle (or Cabinet) (LCC)
A cubicle or cabinet typically containing secondary equipment including control and interlocking, measuring, indicating, alarm, annunciation, and mimic one‐line diagrams associated with the primary equipment. It may also include protective relays if specified by the user, as defined in IEEE C37.122.
1.2.11 Support Insulator
An internal insulator supporting one or more conductors, as defined in IEC 62271‐203.
1.2.12 Partition
Part of an assembly separating one compartment from other compartments. It provides gas isolation and support for the conductor (gas barrier insulator), as defined in C37.122.
A partition as defined in IEC 62271‐203, which is a support insulator of gas‐insulated metal‐enclosed switchgear separating one compartment from other compartments.
1.2.13 Power Kinematic Chain
A mechanical connecting system from and including the operating mechanism up to and including the moving contacts, as defined in C37.122.
1.2.14 Design Pressure of Enclosures
Relative pressure used to determine the design of the enclosure. It is at least equal to the maximum pressure in the enclosure at the highest temperature that the gas used for insulation can reach under specified maximum service conditions. The transient pressure occurring during and after a breaking operation (e.g., a circuit breaker) is not to be considered in the determination of the design pressure, as defined in IEC 62271‐203.
1.2.15 Relative Pressure Across the Partition
Relative pressure across the partition is at least equal to the maximum relative pressure across the partition during maintenance activities. The transient pressure occurring during and after a breaking operation (e.g., a circuit breaker) is not to be considered in the determination of the design pressure, as defined in IEC 62271‐203.
1.2.16 Operating Pressure of Pressure Relief Device
Relative
