The correct answer is: d) excessive heating due to motor overloads and failure to start You'll find the rules for motor and branch-circuit overload protection in Part III of Art. 430 in the 2011 NEC.

Motors and their associated equipment must be protected against both overload and overcurrent (short circuit or ground fault). This function is usually split, with ...

Mechanical overload-protection devices, such as the EAS -Compact backlash-free, ball-detent torque-limiting clutch, can disconnect drive and driven components almost instantaneously. So-called soft ...

Engineers working at robotic companies, auto makers, automatic equipment manufacturers and in many other industries all commonly use torque overload protection devices, slip clutches or torque ...