2 Terms
2.0.1 High-voltage breaker
High-voltage breaker，also called high-voltage switch，can shut off or close the no-load current and the load current in the high-voltage circuit as well as can shut off the overload current and the short-circuit current through the action of the protective relay device when the system is out of service.The high-voltage breaker has complete arc extinguishing structures and sufficient breaking capacity.
2.0.2 High-voltage switchgear panel
A set of power distribution devices are composed of different electric equipment such as high-voltage breaker，load switch，contactor，high-voltage fuse，disconnecting switch，earthing switch，transformer，station power transformer，controlling，measuring，protecting and regulating devices，internal connecting pieces，accessories，shell，as well as supporting frame，with air or composite insulating material as the medium in it，for receiving and distributing the three-phase electric energy of power grid.
In this code，high-voltage switchgear panel refers to the"metal-enclosed switchgear and control device（the switchgear and control devices that are assembled and enclosed in the earthing metal shell，except the external connection，）".
2.0.3 Metal-enclosed switchgear
The switchgear that is enclosed by the metal，except inlet and outlet lines，totally earthing.
2.0.4 Gas-insulated metal-enclosed switchgear
It is the metal-enclosed switchgear，all or some adopting gas（not the air in the atmospheric pressure）as the insulating medium，hereinafter referred to as GIS.
2.0.5 HGIS，Hybrid GIS
HGIS is a simplified GIS，excluding open-type busbar.
2.0.6 Flex section
The connecting part between two adjacent shells of GIS and HGIS，which is used to absorb the displacement caused by thermal flex and non-uniform sinkage，and has a bellows-type elastic joint.
2.0.7 Transportation unit
The part of GIS or HGIS tha is not required to be disassembled and suitable for transportation.
2.0.8 Component
The fundamental part that functions specially in the main circuit of GIS or HGIS，and also the circuit that connects with the main circuit，such as breaker，disconnecting switch，load switch，earthing switch，arrester，instrument transformer，bushing and busbar.
2.0.9 Bushing
The part for one or several conductors passing through separating structures like walls or boxes with the function of insulating or supporting.
2.0.10 Disconnecting switch
A kind of switch which in its disconnected positions，there are required insulation distance and obvious disconnecting mark between the contact terminals；in its closed positions，it can bear the current under the normal conditions and the current under the abnormal conditions during the time specified.
2.0.11 Earthing switch
A kind of mechanical switchgear used to realize circuit earthing.Under the abnormal conditions（such as short circuit），it can bear specified current within the time specified；under the normal circuit conditions，it is not required to bear current.Earthing switch may be combined and installed together with disconnecting switch.
2.0.12 Operating device
The device which is used to switch on and off the switch.
2.0.13 Arrester
A kind of over-voltage limiter.When overvoltage appears，the voltage between two terminals of the arrester will not exceed the specified value to prevent the electric equipment from damaged by overvoltage；after overvoltage action，the arrester can make the system to recover into the normal state.It is also called over-voltage limiter.
2.0.14 Metal-oxide surge arrester
The arrester composed of series and（or）parallel metal-oxide resistors with or without discharge gap，including metal-oxide surge arrester without gap，with series gap or with parallel gap.
2.0.15 Compound shell
The insulating shell made of organic synthetic material and high molecular insulating material respectively.
2.0.16 Discharge counter
A kind of device to record times of operating（discharge）for arrester.
2.0.17 Capacitor
The device to provide reactive power.
2.0.18 Power capacitor
The capacitor used in the power grid.
2.0.19 Coupling capacitor
The capacitor to transfer signal in the electric power system.
2.0.20 Dry-type reactor
The reactor whose winding and iron core（if any）are not soaked in the insulating liquid medium，of which including reactor without iron core（namely，air reactor）and dry-type iron core reactor.
2.0.21 Technicaldocumentations of product
The technical documentation of product which refer to the technical part in the signed equipment contract，as well as the product description，test record，qualification document and assembly drawing provided by the manufacturer.
2.0.22 Equipment and material
The generic terms of equipment and material.