Circuit Breakers are the metaphorical “safety-valves” of electrical systems; a means of giving harmless vent to excessive energy in a circuit, thereby minimizing the risk of damage to equipment that would otherwise be subjected to non-design conditions.
Various power system components depend on the proper operation of a circuit breaker including, for example, expensive power transformers (e.g., in the case of HV and MV circuit breakers) or critical processes in a nuclear power plant (as in the case of LV moulded case breakers).
Testing provides assurances that a circuit breaker will operate and, moreover, will act within expected tolerances. Testing also informs circuit breaker maintenance decisions so that maintenance dollars are spent most wisely and stretch further. Maintenance, of course, is essential to maintain maximum reliability of a circuit breaker.