ECN Forum Forums General Topics of the Trade General Discussion Area Mixing power & low voltage

Master66... sorry, I forgot to check back in on this thread.


Anaerobic plants have "digesters" that break down the sludge in an enclosed space where there is very little oxygen present and as a by-product produce a fairly large amount of hydrogen sulfide and methane gases. Normally you can tell this type of design because of the digesters, which are large (usually circular) buildings with floating roofs. Because of the expected levels of gas there are a large number of locations at the plant that will be classified.

Aerobic plants can have classified areas, but, many few locations at the plant will be a concern. This style plant has large mixing tanks and lagoons that "churn" up the water and use that action to break down the sewage. Because the actual digestion process takes place in the open and in the presence of oxygen there are very few classified areas.

Let me know if you are interested and I'll have Bill post a photo of each design.

ELECTRICAL ENGINEERS ARE LIKE WEATHERMEN (HIT AND MISS)

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).]

Worse... with the attitudes of some, they're like attituded AHJ's without the badges.

"What do you mean you won't do it that / my way? What is this "Code" of which you speak?"