Which statement correctly differentiates a current limiter from a circuit breaker?

Which statement correctly differentiates a current limiter from a circuit breaker?

• A. Circuit breakers can be reset after fault.
• B. Current limiters are single-use and must be replaced.
• C. Both are one-time use.
• D. Current limiters can be reset after fault.

Answer: (B)

After a fault, the way protective devices are returned to service distinguishes them. Circuit breakers trip to interrupt current and can be reset after the fault is cleared, restoring normal operation. Current limiters are sacrificial devices: once they act to constrain fault current, they cannot be reused and must be replaced. This is why the statement that current limiters are single-use and must be replaced best captures the difference. The other options blend reset capability with the protection type in a way that doesn’t reflect their true behavior: circuit breakers are indeed resettable, but current limiters are not, and saying both are one-time use or that current limiters can be reset are incorrect.

After a fault, the way protective devices are returned to service distinguishes them. Circuit breakers trip to interrupt current and can be reset after the fault is cleared, restoring normal operation. Current limiters are sacrificial devices: once they act to constrain fault current, they cannot be reused and must be replaced. This is why the statement that current limiters are single-use and must be replaced best captures the difference. The other options blend reset capability with the protection type in a way that doesn’t reflect their true behavior: circuit breakers are indeed resettable, but current limiters are not, and saying both are one-time use or that current limiters can be reset are incorrect.