The final mandatory piece of the motor control circuit puzzle is a mouthful: “Motor and motor branch circuit short circuit and ground fault protection.” Let’s chew on it a little.
A short circuit often involves electric arcing at the point of contact. Resulting burning and expulsion of molten metal poses a serious fire and personnel safety hazard, as well as significant potential for equipment damage. Arcing due to motor winding insulation failure, if allowed to persist, will damage the steel laminations, increasing the extent and cost of work required to repair the motor.