Purpose and Principles of Time-Travel Testing – 6 minutes
Briefly states the purpose of circuit breaker time-travel testing. Explains why contact timing is important to the proper operation of a circuit breaker. Describes the basic principles of performing a timing test.
Circuit Breaker Operations – 8 minutes
Defines the trip, the close, and the trip-free circuit breaker operations. Identifies examples of when each operation would be performed. Describes how the breaker mechanisms function for each operation.
Circuit Breaker Time Characteristics – 5 minutes
Defines the following circuit breaker time characteristics: main contact time, resistor contact time, contact synchronization. Briefly explains why each time characteristic is important to the proper operation of a circuit breaker.
Circuit Breaker Travel Characteristics – 9 minutes
Defines the following circuit breaker travel characteristics: stroke, overtravel, total travel, rebound, contact wipe, average velocity. Briefly explains why each travel characteristic is important to the proper operation of a circuit breaker.