A(n) ___ circuit breaker has an intentional delay between the time the overload is sensed and the time when the breaker operates.

• A. inverse-time
• B. instantaneous trip
• C. non-delay
• D. magnetically sealed

Answer: (A)

Time-current characteristics govern how long a breaker waits before opening after an overload. An inverse-time breaker intentionally delays its trip, with longer delays for smaller overloads and shorter delays as the overload grows. This lets brief surges or motor inrush pass without tripping, while still tripping sooner if the fault persists or becomes severe, providing coordination with upstream protection. An instantaneous trip would act with no deliberate delay, and a non-delay device would not accommodate short-lived surges; the term magnetically sealed isn’t related to this time-delay behavior.