Once again, I encountered some clever person who was able to "create" 110 in a 220v system by grounding the neutral screw to the box.
While I corrected the situation, I was challenged to show where this dangerous practice was banned. After all, the NEC does allow uninsulated neutrals (grounded conductors).
Other than noting that "raceways" contain, rather than act as, conductors, and noting that the code has no ampacity tables for EMT, I am at a loss as to just where this practice is explicitly banned.
Considering that I was once fired for objecting to this practice, I sure would like some better references. Any suggestions?
