Re: Height of circuit breaker panelboards
The NEC does not have a maximum height restriction for panelboard enclosures.
The restriction is for the breaker handle height.
404.8 Accessibility and Grouping.
(A)Location. All switches and circuit breakers used as switches shall be located so that they may be operated from a readily accessible place. They shall be installed so that the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than 6ft 7in. above the floor or working platform. This is quoted from the 2002 NEC
So the switch dictates how high the enclosure can be. There are exceptions.
This height was changed in the 1996 code cycle.
Pierre