Principles of Operation - 13 minutes
Explains how oil, air-magnetic, vacuum, and SF6 circuit breakers open contacts and extinguish arcs. Uses actual breaker hardware and color diagrams. Describes how protection circuits detect line over-currents, over-voltages, and under-voltages, and operate with breakers.
Routine Maintenance – 29 minutes
Shows how to rack out, inspect and clean the interior of air-magnetic and vacuum breakers. Describes how to remove oil from a oil circuit breaker for testing. For SF6 breakers, demonstrates how to perform visual inspections, how to remove and handle SF6 gas. Demonstrates routine electrical tests for all breakers.