A 14-gauge solid copper wire used in a general circuit should be protected by a fuse or breaker rated at how many amperes?

A 14-gauge solid copper wire used in a general circuit should be protected by a fuse or breaker rated at how many amperes?

• A. 10 amps
• B. 15 amps
• C. 20 amps
• D. 25 amps

Answer: (B)

The main idea here is matching overcurrent protection to the conductor size. A 14-gauge solid copper wire used in a general circuit is typically rated to carry about 15 amperes safely. So the protective device—fuse or breaker—should be 15 amperes to trip before the wire overheats. Using a 20-amp device would allow currents that could heat a 14 AWG conductor beyond safe limits during overloads or faults, risking insulation damage. A 10-amp device would under-protect and could nuisance-trip under normal loads. Therefore, 15 amperes is the correct protection rating. If a higher protection level were needed, you’d use larger conductor, such as 12 AWG, instead of increasing the breaker to 20 A on 14 AWG.

The main idea here is matching overcurrent protection to the conductor size. A 14-gauge solid copper wire used in a general circuit is typically rated to carry about 15 amperes safely. So the protective device—fuse or breaker—should be 15 amperes to trip before the wire overheats. Using a 20-amp device would allow currents that could heat a 14 AWG conductor beyond safe limits during overloads or faults, risking insulation damage. A 10-amp device would under-protect and could nuisance-trip under normal loads. Therefore, 15 amperes is the correct protection rating. If a higher protection level were needed, you’d use larger conductor, such as 12 AWG, instead of increasing the breaker to 20 A on 14 AWG.