Article 90.2(B) cover's the things the NEC does not cover, and a sewer plant is not one of them. I worked for a electric utility for 25 years so knew utility companies were exempt, and that mines were also. I once did a upgrade at a cable company facility once with all them huge satalite dishes (doing this while employed for electric utility moonlighting), upgraded service, several outlet's and lighting, couple of A/C units etc. and I pulled a permit of course and when the inspector came he wasn't sure if I even needed to pull a permit beings it was a communications type of building, but we figured with all new electric stuff good idea but later on the racks and stuff that cable company was going to put in would be exempt.
but as for comm. wiring with 480v wiring I have spent some time in steam/nuclear/hydros power plants and have mixed them and not have any problem's, but then there been times when did get interference and have to run seperate conduit along side the cable tray for the comm. circuits.
BUT any how a sewer plant is not exempt from the NEC thats for sure.
this board is good, sure makes you look up stuff..
[This message has been edited by highvoltageguy (edited 03-27-2005).]
