Vacuum Interrupter

A vacuum interrupter is a switch that uses electrical contacts enclosed in a vacuum, and it serves as the core switching component of medium voltage, generator and high voltage circuit breakers. When its contacts separate under load they briefly form a metal vapor arc that extinguishes quickly in the vacuum, and the device is markedly more compact than switchgear that instead uses air, sulfur hexafluoride or oil as its arc suppression medium. Vacuum interrupters are widely used in utility power transmission, generation and distribution, including railway, arc furnace and industrial plant systems, and can serve either as circuit breakers in substations and generating stations or as load switches for grid end users. They are typically enclosed in glass or ceramic with a hermetic seal, use contacts of a copper chromium alloy, and are built sealed for life, with bellows rated for more than 30,000 open close cycles without maintenance.