What is the ampacity of a 10 AWG THHN copper conductor?

The ampacity of a conductor refers to the maximum amount of electric current it can safely carry without exceeding its temperature rating. For 10 AWG THHN (Thermoplastic High Heat-resistant Nylon-coated) copper conductors, the National Electrical Code (NEC) provides guidelines on determining ampacity based on insulation type and installation conditions.

For a standard THHN copper conductor, the ampacity is typically set at 30 amps when used in a standard installation condition where it is not bundled tightly with other conductors and the ambient temperature is within the allowable range. The ampacity can vary with factors such as the number of conductors bundled together or the surrounding temperature, but for single conductors in typical conditions, 30 A is a widely accepted value based on NEC tables.

Consequently, while the ampacity of 10 AWG can sometimes be misunderstood, the correct value in most scenarios aligns with 30 amps. Therefore, the correct answer reflects the established ampacity for 10 AWG THHN copper conductors in standard conditions as defined by the NEC.