Which gauge wire is used in a 30A circuit?

In a 30A circuit, the correct wire gauge is 10. Using 10-gauge wire is crucial because it is designed to safely handle the current without overheating. The National Electrical Code (NEC) specifies that for a circuit carrying 30 amps, 10-gauge copper wire or 8-gauge aluminum wire should be utilized. This ensures that the wire can effectively carry the load and prevents any potential hazards related to overheating or electrical fires.

The other wire sizes—12, 14, and 8—do not meet the necessary criteria for a 30A circuit. A 12-gauge wire is typically rated for 20 amps and therefore is inadequate for higher loads. Similarly, a 14-gauge wire, which is rated for 15 amps, is also unsuitable for a 30A circuit. While 8-gauge wire can also technically suffice for a 30A circuit, it may be more than what is required, and is commonly used for higher amperage circuits. Thus, 10-gauge wire is the standard choice for safety and compliance with electrical codes in a 30A circuit.