Mike: A well thought out reply. I might point out one thing, which is that although AC drives are very flexible and can often be used acceptably with a fixed ratio drive, it can be possible to get a *further* improvement in efficiency *and* performance with the addition of another gear ratio or a reconnection of the motor on the fly. The idea is either to keep the motor spinning where it is wound to be efficient (gear change), or to change the connection of the motor to match the speed range. Of the two, the gear change is the easiest for the average conversion.
Seth (not Murray)
