A good friend of mine, who is a housing inspector; don't groan he always checks electrical questions with an electrician; recently inspected a new duplex; i.e. two dwelling units in one building. The duplex has a swimming pool for the use of both sets of occupants. In order to split the pool operating cost equitably the owner has brought one side of the 240 volt feeder from each service. I know this is wrong but I'm having trouble matching chapter and verse to this particular transgression. If anyone would be willing to help me out it would be appreciated.