If a circuit breaker has not been operated in normal service, a periodic open-close exercise should be planned.

• A. True
• B. False
• C. Not necessary
• D. Only for new equipment

Answer: (A)

Regular mechanical exercise of circuit breakers that haven’t been used in normal service is essential to maintain reliability. When a breaker sits idle, its moving parts can become stiff, lubricants can dry, and springs can lose tension or become misaligned. Without periodic operation, these issues may not be apparent until a fault occurs, risking delayed or failed trip or close when needed.

Planned open-close cycling verifies that the mechanism can move freely, the trip coil engages properly, and the contacts and enclosure seal as intended. It helps catch developing problems early, ensuring the breaker will operate correctly during an actual fault. This practice applies to all equipment that isn’t regularly operated, not just new gear, and is part of maintaining overall electrical safety and reliability.