The document summarizes the key topics in testing high voltage circuit breakers, including different breaker types, components, and performance characteristics that can be measured. It describes testing various aspects of breaker performance like timing, travel, power factor, contact resistance, and minimum pick-up voltage. Common breaker types include oil, SF6 gas, air, and vacuum designs, which may use spring, hydraulic, pneumatic or magnetic actuating mechanisms. Tests evaluate insulation components, contact quality, command coils, and verify performance meets specifications.