Relationship Between Historical Trends, Equipment Age, Maintenance, and Circuit Breaker Failure Rates

Circuit breakers are ubiquitous devices that vigilantly protect personnel, equipment, and critical functions. But circuit breakers fail-and how they fail matters. The U.S. Army Corps of Engineers collected and analyzed a database of equipment records over several decades. This article studies the details of that database to provide new insight to failure trends, showing that failure rates have varied historically, that failure rates change as a function of equipment age, and that failure rates respond to preventative maintenance activity, often counterintuitively. New figures show unpublished details that improve understanding and reveal limitations of previous circuit breaker statistics. These data challenge persistent assumptions of reliability-centered maintenance and reliability design.