Why is it necessary to perform periodic testing of correctly rated and properly installed circuit breakers?

Correct Answer: Option C — to insure they will continue to provide the original degree of protection

Circuit breakers are mechanical devices subject to wear, oxidation, and lubricant degradation over time. Periodic testing is essential to verify that trip mechanisms, arc chutes, and contact pressures remain within design specifications, ensuring the breaker will reliably interrupt fault currents and protect the distribution system as intended.