This part of GB/T 2900 specifies general terms related to high-voltage switchgear and controlgear with a rated voltage of 3.6 kV and above (hereinafter referred to as switchgear and controlgear), general assembly of switchgear and controlgear and its components, and switchgear Definitions of electrotechnical terms such as its components, operation and characteristic parameters. This part applies to circuit breakers, isolating switches, earthing switches, load switches, bypass switches, transfer switches, isolating circuit breakers, reclosers, sectionalizers, contactors, starters, combined electrical appliances, metal-enclosed switchgear and other switchgear and control equipment. See GB/T 15166.1 for the term standard of high-voltage AC fuses.