Electrical conduit on the floor ?

Aluminized, actually.

Harold

That would certainly be my choice, assuming it's possible under the circumstances.

Harold

At my factory job, there are machines, lifts etc. with EMT conduit running on the floor. Best I can get from the codes are that the conduit must be supported(anchored) less than or equal to every 10 feet and 3 feet from terminations. I don't have specs to floor areas w/traffic. Check out Chapter

358.xx (2002) Another poster suggested THWN wire, and I strongly agree. The "W" is for wet.

Luck, Brian

Sounds like a good way to make an enemy you don't need on the off chance you might be able to get his ruling changed.

Here's what the NEC has to say,

"The authority having jurisdiction for enforcement of the Code will have the responsibility for making interpretations of the rules, for deciding on the approval of equipment and materials, and for granting the special permission contemplated in a number of the rules."

Ned Simmons

There may be aluminized the EMT, but I've never seen it. It's pretty obvious EMT is galvanized when you weld it.

Ned Simmons

Yup..you get that nasty yellow mang that grows on it...

Gunner

That rifle hanging on the wall of the working-class flat or labourer's cottage is the symbol of democracy. It is our job to see that it stays there. - George Orwell

Could be you and I have egg on our faces. I am almost certain I have seen stickers on some EMT that says it is aluminized, but I'll be damned if I can find anything that indicates I'm right when I do a search on the web. Maybe my next trip to an electrical supply warehouse will bear fruit.

Harold

Harold

Use LiquidTite conduit if there is any chance of standing or running water. As long as it isn't a trip hazard, the inspector shouldn't have any problems with it. We used to use it all the time for power runs under raised computer-room floors, where there was a chance of water if and when the HVAC system leaked, or in one case, the roof on an old building.

You should have a short length of flex at the machine end, anyway, if you use rigid conduit -- with liquid-tite, you don't need to bother with that, so saves you a bit of trouble there.

Regards,

Bob

It's galvanized, just with a thin coating. Usually electroplatd on rather than hot dipped.

Somewhere I have seen a chart that graphs the coat>>"TeamCasa" writes:

There has been aluminum EMT.

It is rather famous for destruction of concrete buildings where it has been embedded in concrete.

I cannot recall if the best book on the subject is "Design and Construction Failure" or "Construction Failure" or "Why Buildings Fall Down", or one of the similar books. But one of them has a good piece on it.

There are several types of metal conduit - the most common being EMT (zinc electoplated steel in most cases, cold galvanized in others) , Rigid conduit (heavy walled steel conduit) and aluminum conduit(similar to rigid but "soft" aluminum) EMT, or Electro Metalic Tubing is connected with clamps and sleaves - it is too thin to thread. Rigid and aluminum comduits are generally threaded.

Construction

How does aluminum damage concrete?

Back when I was doing wiring there was a new product just comming out called IMT ( I think ) Intermediat Metalic Tubing. Is it still around? ...lew...

Yes it is it takes the same threaded connectors as rigid even though it's slightly smaller in diameter.

It sets up a galvanic couple with iron rebar, with the result that the rebar is rapidly corroded away, weakening the concrete structure. Concrete is alkaline, and it never really completely dries, so it acts as the electrolyte of the corrosion cell.

Gary

Aluminum is lower in the galvanic series, so it's more likely the aluminum expands as it corrodes, stressing the concrete.

Ned Simmons

Yep. Still remember the windows in our former embassy in Cuba, where steel screws had been used to attach aluminum. The more electronegative was eaten up to an inch clear away, leaving the screws to finally rust in the salt air while we were away.

That's why they galvanize instead of use lead paint under your car.

I'm going to bet, however, that the interior of the conduit has enough room for the developed aluminum oxide.

It is _always_ appropriate to ask for a statement in writing--it eliminates potential for future misunderstandings. Any inspector who has a problem with writing down his interpretation is already your enemy. Just ask him politely and make it clear that you want to have it down so that you don't forget something important later.

That's my point, exactly. I had already stated that one might be up against an attitude. My experience thus far has been nothing but positive where inspectors are concerned. I've wired two facilities with 3 phase power and the inspectors have been very helpful by suggesting methods around particular problems. I have a copy of the code, but it's not always easy to fine the exact thing you're looking for. The guys here in Washington State seem to have it all in their heads, and so far it's in lock step with code as I interpret it once I find it, thanks to their help.

Harold