What is Switchgear?
In an electric power system, switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done, and to clear faults downstream. This type of equipment is directly linked to the reliability of the electricity supply.
How can they be classified?
There are several different classifications of switchgear that can be made. These include classification by:
- Current rating
- Interrupting rating
- Voltage class - such as low voltage (less than 1 kV AC), medium voltage (1 kV AC through to approximately 75 kV AC), high voltage (75 kV to about 230 kV AC), and extra high voltage (more than 230 kV).
- Insulating medium - such as air, gas, oil, vacuum, and carbon dioxide
- Construction type – such as indoor, outdoor, industrial, utility, marine, metal-enclosed, metal-clad, arc-resistant and more
- IEC degree of internal separation – such as no separation, busbars separated from functional units, terminals for external conductors separated from busbars or functional units, functional units or terminals separated from each other, etc.
- Interrupting device - such as fuses, or air/oil/vacuum/gas/CO2 circuit breakers
- Operating method – such as manual, motor/stored energy, and solenoid operated
- Type of current – such as alternating or direct
- Application – such as transmission system or distribution
- Purpose – such as isolating switches, load-break switches, and grounding switches
Ratings, design, specifications and details of switchgear are set by a multitude of standards. In North America mostly IEEE and ANSI standards are used, much of the rest of the world uses IEC standards, sometimes with local national derivatives or variations.
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To learn more about IEM's switchgear, including VESTA-AR, our medium voltage metal-clad
arc-resistant switchgear that makes efficient use of available floor space and minimizes the time required for inspection, repair and maintenance of equipment, download our white paper or contact us today.
