Free Texas Journeyman Electrician Exam Flashcards

Ampacity is the maximum current in amperes a conductor can carry continuously under its conditions of use without exceeding its temperature rating. It depends on insulation temperature rating, ambient temperature and the number of conductors bundled together. The breaker rating is the protective setting selected from that limit and the load, so the two numbers are related but not interchangeable. Using touch or warmth to judge a conductor ignores the temperature rating that defines ampacity.