Open knife switches were supplanted by safety switches with current carrying contacts inside a metal enclosure which can only be opened by switching off the power. In modern applications, automatic switches (such as contactors or relays), and manual switches such as circuit breakers are used. These devices use a snap action mechanism which opens the switch contacts rapidly, and feature an arc chute where the arc caused by opening the switch is quenched. These devices also prevent injury due to accidental contact, as all of the current carrying metal parts of the switch are hidden within or surrounded with insulated guards.
Wipo Publishes Patent of China Southern Power Grid Electric Power Research Institute, China Power Engineering Consultants Group Southwest Electric Power Design Institute, Chuang Fu, Yimin Wu, Hong Rao, Shukai Xu and Xiaolin Li for "Power Transmission Line De-Icing System and Method Thereof Implemented Using Back Braking Operation during the Whole Process" (Chinese Inventors)
Mar 01, 2013; GENEVA, March 1 -- Publication No. WO/2013/026253 was published on Feb. 28.Title of the invention: "POWER TRANSMISSION LINE...