What conductor size is necessary for a 120-volt circuit supplying a load of 30 amperes considering Code limits?

To determine the correct conductor size for a 120-volt circuit supplying a load of 30 amperes while adhering to electrical code standards, it is essential to consider the ampacity of conductors. Ampacity is the maximum amount of electric current a conductor or device can carry before sustaining immediate or progressive deterioration.

In this scenario, the National Electrical Code (NEC) provides guidelines on conductor sizes based on the load and the material (copper or aluminum) used. For copper conductors, a 3 AWG wire has an ampacity of approximately 100 amperes under typical conditions, which comfortably exceeds the 30-ampere load requirement and ensures that the wire will not overheat.

Choosing a conductor size larger than necessary can help prevent voltage drop over long distances and can accommodate any future load increases. Therefore, the option indicating 3 AWG is justified as it meets the current load requirement with ample capacity, ensuring safety and compliance with code limits.