Motor overheating and water ingress protection circuit

Almost all burned out motors have a very high temperature rise in their windings before they are damaged; in many cases, water can easily enter the motor, causing it to burn out. The circuit shown in the figure. It can prevent overheating and water intrusion accidents. RT is a positive temperature coefficient thermistor (PTC for short); M and N are two plastic wires buried in the stator winding of the motor that are very close together and have their insulation stripped off to detect water ingress into the motor. T is wound with about 290 turns of enameled wire on the outer layer of the AC contact coil KM, and a voltage of 12V can be obtained.