Exam 2: Fuses, Disconnect Switches, and Circuit Breakers

Switching voltage surges are usually limited to three times normal voltage.

____ is the current-limiting characteristic of a transformer and is expressed as a percent.

Adding a(n) ____________________ to the nonautomatic circuit breaker, by using a bimetallic element in each pole of the breaker, provides automatic tripping.

Peak let-thru current (Ip) and ampere squared seconds (I2t) are two measures for the degree of ____ provided by a fuse.

The main purpose of a ground fault circuit interrupter (GFCI) is to ____.

____________________ fuses are used today in almost all fuse applications.

The 120 VAC circuit is normally protected by a single fuse or circuit breaker.

All protective devices have a published ____________________, which is defined as the highest current at rated voltage that a device can safely interrupt.

The typical fuse consists of an element surrounded by a filler and enclosed by the fuse body. The element is a calibrated ____.

By programming a motor-protective relay unit with the motor's electrical characteristics, the unit's algorithm will automatically tailor the optimal protection curve to the motor being monitored.