What is the purpose of running overload protection for a three phase motor?

An electrical circuit is designed to carry a certain amount of energy, or voltage. The flow of energy, called a current, should travel through the path from one point to the other unimpeded. If that current is interrupted, it causes what is commonly known as a short circuit. If an electrical system is designed properly, overload protection kicks in to stop the flow of energy until the source of the interruption is removed.