In the NEC, ampacities refer to the ____ abilities of conductors.

• A. Heat resistance
• B. Current carrying
• C. Mechanical strength
• D. Voltage rating

Answer: (B)

Ampacity is about how much current a conductor can carry safely. In the NEC, ampacity refers to the current-carrying capability of a conductor or its insulation—the maximum continuous current in amperes that the conductor can carry without the temperature rising enough to damage insulation or exceed its rating under the installation conditions. This focuses on the heating effect of current and how heat is managed, not on how well the material resists heat, nor on its mechanical strength, nor on the voltage the insulation can withstand. So ampacity tells you the conductor’s ability to carry current, which is why the option describing current carrying is the best fit.