Why do electric motors burnout?

I would guess by overloading or by running at too low a voltage which has the same effect. The amperage goes beyond the rated amperage if overloaded. read more

Repairing an electric motor, in such a case, is a time consuming process. The other thing that may happen before this is that the brushes may burn out. The brushes are rotating contacts that supply electricity to the rotating part of the motor, and are usually carbon pads on a metal ring. read more

After all the coils of wire do mot move (relative to each other). Obviously over temperature can cause insulation to break down but why should a motor ever get excessively hot. Surely it is simple and low cost to fit a thermal cut-out or am I missing something. read more