What does "breaking capacity" of a circuit breaker mean?

• A. The maximum fault current the breaker can interrupt without damage at a given voltage.
• B. The maximum current at which the breaker will trip for overload.
• C. The maximum speed at which the breaker can operate.
• D. The maximum voltage rating of the breaker.

Answer: (A)

Breaking capacity is the maximum fault current a circuit breaker can interrupt without damage at the specified system voltage. This measure tells you how severe a short-circuit the breaker can safely clear. It reflects the breaker’s ability to break the current and withstand the arc and stresses during that fault without failing or welding contacts. It’s not about the current level that causes the breaker to trip for an overload—that’s a different setting related to its thermal or magnetic trip thresholds. It’s also not about how fast the breaker operates in general or its voltage rating, which refers to the maximum voltage it can safely interrupt.