What is the maximum amperage that No. 10 THW wire can carry?

What is the maximum amperage that No. 10 THW wire can carry?

• A. 20 amps
• B. 25 amps
• C. 30 amps
• D. 35 amps

Answer: (C)

No. 10 THW wire is rated based on its ability to safely carry electrical current under specific conditions, including temperature and installation environment. According to the National Electrical Code (NEC) and standard wire ampacity charts, No. 10 THW wire typically has a maximum ampacity of 30 amps when installed in a manner that allows for heat dissipation, such as in free air or in conduit.

This ampacity rating is important for electrical contractors to ensure that the wire is not overloaded, which could lead to overheating and potential fire hazards. The rating may vary in different installation conditions or when using different types of insulation, but for general purposes and under standard conditions, 30 amps is the accepted maximum for No. 10 THW wire.

The choices of 20 amps, 25 amps, and 35 amps do not align with this standard for No. 10 THW wire under normal conditions, making 30 amps the correct and safe answer.