Why Motor Circuits Are Different
Motors are not like lighting or receptacle loads. They draw significantly more current during starting than during running — often 6 to 8 times full-load current for several seconds during across-the-line starting. This inrush must be accommodated in the overcurrent protection device without nuisance tripping, while still providing protection against sustained overloads and short circuits. NEC Article 430 addresses this by separating motor circuit protection into distinct functions: branch circuit conductors, overload protection, branch circuit short-circuit and ground-fault protection, and disconnecting means.