Re: Exception to the rule of grounding.....need answer!!!!
A lot of tools and equipment are double insulated with metal enclosures. The metal is necessary for physical protection.
The first clue is the tools will not have a grounded cord or attachment plug. Garbage disposals and trash compactors have metal enclosures and frames.
I got hammered by two of the professional code instructors, Joe Tedesco and R Keis, for my view on grounding. My view is substantiated in many cases.
50 years ago, I protested the emphasis on grounding and the cost. Equipment grounding, in many cases, is still a big waste of money and resources.