The only code reference (other than the ones cited for switches..) that I can find for your query is in 240.24. The overcurrent device has to be readily accessible..so this precludes requiring the use of ladders to reach the handle (exceptions exist, of course). I suppose that the defacto elevation requirements would be the same 6' 7" as for the switches, or breakers used as switches. After all, isn't someone eventually going to operate the breaker by hand?
The exceptions seem to hinge around the notion that it's ok to have the overcurrent device NOT readily accessible so long as there is a downstream overcurrent device for switching the load off line.
[This message has been edited by Elzappr (edited 04-03-2003).]