CIRCUIT WATCHMAN

CD 2478089 E&MP15.008

Electric Circuits, Breakers

1930

This 138 kilovolt circuit breaker is being prepared for a high voltage test at the East Pittsburgh works of the Westinghouse Electric & Manufacturing Company before it goes into service on a transmission line.

One of its jobs will be to open the circuit in as little as one-eighth of a second in the event of a short circuit on the line.

The electric arc obtained upon opening of a short circuit is quenched in this breaker by means of deionizing units on the contacts. 

Original Caption by Science Service
^©Westinghouse