Conductor Ampacity: Why Termination Ratings — Not Wire Insulation — Control the NEC Limits

Conductor ampacity is one of the most misunderstood parts of the NEC. Many installers assume the wire insulation rating controls everything, but in reality, termination ratings and installation conditions determine which ampacity column you are allowed to use. This is where a lot of installations go sideways. Not because the table is confusing — but … Read more