Electrical conduit on the floor ?

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I want to run EMT conduit along my concrete floor to power my lathe. The arrangement is such that I'm not worried about someone tripping over it. But it is possible that water could leak because of a broken pipe, hole in the roof, etc. and come into contact with the wiring. I plan on using compression fittings and making the conduit as water tight as I can.
Does anyone know if the national electrical code permits installing conduit on the floor? I borrowed the 2002 NEC Handbook from the local library, but I can't find any mention of where conduit should be installed. The book is 1200 pages and the index didn't help. Which chapter should I look in?
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On Thu, 08 Jul 2004 04:24:49 +0000, AL wrote:

Conduit can be and frequently is placed below ground level (mostly plastic these days), so I can't see a problem with what you propose. There might be a local requirement for direct burial rated wire, and you certainly wouldn't want junctions that weren't water proof on the floor if there was a potential for flooding.
I've had THC in cemented plastic conduit for an underground conduit approved, but local regulations can be different. I'd suggest checking with your local inspection department.
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. >I'd suggest

I second that.
I'm having problems with the fire dept. over code. The bottom line is what ever the inspector will except. The code is often left up to the inspectors "interpretation" of said code. It's his way or the high way.
Randy Hansen

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If you have one of those hard-nosed inspectors that likes to jerk you around, tell him to put it in writing and sign and date it. That can get them to back off if they aren't enforcing code, but their own desires. You'd be surprised how often they have no authority to make you do things the way they want. It's an old ploy those that have an attitude use to run you in circles. Once they sign it and it's not necessary for code compliance, you have them in your palms, assuming the local government isn't totally corrupt. That's something I learned from an old acquaintance that worked as a wireman for the majority of his life.
Harold
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says...

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
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Ned Simmons wrote:

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.

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--John
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I would be concerned with 358.12(1) which states that EMT is not permitted in areas subject to severe physical damage. That right there would cause me to run IMC or RMC on floors. To take care of the water, make sure the wire you use is listed as THWN. Table 310.13 has all the types of wires and where they can be used.
Nate
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you may wish to consider using rigid conduit rather than EMT - it costs a little more (not much) and is a lot more resistant to damage.

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I usually assume that below grade conduit is full of water and am often right. It seldom causes a problem. Use a type of wire with "W" in the designation, avoid splices, and all will be fine.
Vaughn
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I don't know what the code says, but have you considered using rigid conduit instead of EMT? It is more like iron pipe than tubing and uses pipe threads to make connections.
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Larry Wasserman Baltimore, Maryland
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I worked with a company a few years ago that allowed you to do most anything (when you ran wire) as lone as the first device, terminal or connection was 18" above the floor line. Seems they had floods from time to time and if the first opening or connection was above the water level, you could treat it as you would any other wire run. R, Wink

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Ron Thompson On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA
http://www.plansandprojects.com
The ultimate result of shielding men from the effects of folly is to fill the world with fools. --Herbert Spencer, English Philosopher (1820-1903)
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A possibility you might look into to get you around elctrical codes is a more elaborate form of extension cord. In other words a good robust length of cab-tyre covered where it crosses the floor with some of that heavy duty poly cable protector used in computer rooms. The size you would need is about an inch and a half high and four inches wide, formed like a very shallow inverted U. You glue it to the floor with silicone and it will protect the cable, minimize the probability of your tripping over it and allow equipment like welding carts to be wheeled over it without trouble.
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EMT should not come in contact with a floor as it will rust. If you can keep it above the floor/away from moisture it should be fine.
Dave

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EMT is galvanized.
scott
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On Thu, 08 Jul 2004 23:53:11 GMT, snipped-for-privacy@slp53.sl.home (Scott Lurndal) wrote:

Tell that to the people who try to bury EMT outside - that galvanized coating won't last long at all in constantly wet conditions. I have two buildings that let amateurs do their repairs and are going to have to dig up 250'+ each of EMT buried about 3" down under the lawn...
(One was the pool man redoing the pool lights wrong, and the other was the original developer cheaping out on the outside lighting.)
EMT should be fine going across the floor of your shop to the machines as long as it's not constantly wet, and running from the wall behind the machine - not across a normally accessed aisle and presenting a tripping hazard.
We're talking about a home shop, you don't need to make it thoroughly bulletproof like you would in a commercial shop. For a business, you'd cut and trench the floor and place PVC conduit under the slab to each machine location, and convert to a Rigid coupling (or place a rated floor box) where it pokes through the floor...
The suggestion to make the conduit one-piece across the floor (down, across, and up with one stick) is a good one, because even raintight couplings will leak if they are submerged - and the normal cast-zinc couplings break easily if they get any sort of abuse, which would let moisture inside easily. If you can find them, get the steel fittings.
Use THWN wire in the pipe, even if it gets wet it will last for several years.
--<< Bruce >>--
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Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
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Somebody wrote:

Sorry Charlie, but only the best get to be Star Kissed.
EMT is definitely NOT galvanized.
--
Lew

S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
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Where do you get EMT that isn't?
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"Greg" writes:

Anyplace that sells EMT.
It has a quasi rust proofing process applied, but it is a long way from hot dipped galvanize.
HTH
Lew
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