OK-415W Main Heater Circuit Breaker Tripping

I have received your email about the breakers tripping.  It sounds like there is a short somewhere on the heater circuit.  It is hard for me to give you a precise location to look without being there.  It could be wires in the drum.  This is my first thought.  The power wires going from the end of the commutator to the heaters.  I would remove the commutator holder tube from the end of the drum so you have slack and then pull the wires into the center of the drum and visually inspect them.  It could also be the contactor shorting.  You can remove the top cover and do a visual inspection of the contacts making sure one is not broken. Typically if the large circuit breaker is tripping, this means a large power wire has a short somewhere. So this typically does not indicate a heater short but a large wire short.