after futher reviewing iso ground online...
i've read that installation in plastic boxes nailed to wood frames wouldn't require a forth conductor and that the bare conductor in nm 12-2(home run) ie..dedicated would suffice the iso requirement for device....yet i cant help but wonder if noise couldn't somehow get through nm and cause havoc on my installation. where 12-3 would seem better because wires are twisted and red wire identified green would be insulated and perhaps ensure a better noise free installation? any thoughts? would be cost effective in nm with plastic boxes...but if metal sheilds isolated circuit then perhaps 12-3 mc into metal box would be best route.
thanks,
H2o
