Circuit breaker
A switch in which the open-circuit state is produced automatically under given conditions.
Note 1: The device may also be used for manual operation under normal conditions.
Note 2: If the open-circuit state is produced sufficiently quickly to prevent the short-circuit current from attaining its full value, the term high-speed circuit breaker is applied.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)