Sounds like the motor windings are toast. The breaker is supposed to trip before the motor overheats too much, but this is an approximate thing in practice. The varnish insulation on the windings gets soft when it overheats, and if it happens repeatedly (by resetting the breaker multiple times in a short time period) the insulation eventually breaks down and the coil shorts out between windings. This makes a coil that is supposed to be, say 100 turns, act like it has say 5 turns, which makes the overall resistance of that coil a whole lot less than it's supposed to be, which increases the current level it takes to maintain the voltage potential (120V) across that coil. The high current load trips the breaker. Sorry for the long explanation. I got a little carried away. Time for a new disposal Good luck, Al K