A small fractional HP pump stopped working in a customers little garden pond (she creates a 12 inch waterfall with it). The braided line from a duck decoy had been sucked into the intake(no filter)and wrapped around the impeller shaft and stopped the submerged motor cold for a couple days.
I took the cover off, removed the string, and reassembled it and it works fine.
What prevents this motor from overheating and shorting the windings?