aluminum conduit - uses permitted

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thinfool

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I am getting started on wiring a truck stop. The maintenance guy/electrician for the petroleum supplier tells me that he uses aluminum conduit underground...coated with a two-part epoxy to resist corrosion. (he uses it because it is easier to bend.)
Is this a valid way to use aluminum?
One report that I read (1999) said that aluminum cannot be used unless it has additional corrosion protection. It went on to say that no coating has been investigated (by UL, I guess) that provides this protection, so the use of aluminum underground is not allowed.

Is this still true? (Believe me, I do not want to run aluminum conduit underground) :(


Thanks!
 
Re: aluminum conduit - uses permitted

Why would you want to use it ? Seems pvc would be better choice and last forever with no extra problems like coating it :confused:
 
Re: aluminum conduit - uses permitted

I was at the supply house a little while ago, and the counter supervisor told me that PVC supplies are being seriously impacted by Katrina. They are under orders from the bosses not to sell more than $1000 worth of PVC to anyone so as to try to keep it in stock.
 
Re: aluminum conduit - uses permitted

it has gone up some.Check with big orange,i am willing to bet they will sell you all you need.Like always its price gouging and using katrina to justify it
 
Re: aluminum conduit - uses permitted

Thanks guys, but my question about underground aluminum had to do with wiring to the gasoline pumps and dispensers.
I know that pvc can be used with certain limitations, but I am trying to formulate an argument against using the coated aluminum.
Personally, I just cannot see using aluminum underground at all.
I guess I should have added that this maintenance person told me that he has already purchased the aluminum for this job. I don't want to see it installed, only to be rejected by my inspector.
"An ounce of prevention...etc."
 
Re: aluminum conduit - uses permitted

The following is for general underground installations. From the 2004 Edition of the UL White Book.
CONDUIT, RIGID NONFERROUS METALLIC (DYWV)

USE
Aluminum conduit used in concrete or in contact with soil requires supplementary corrosion protection.

UNEVALUATED FACTORS
Supplementary nonmetallic coatings as part of the conduit have not been investigated for resistance to corrosion.
Click to expand...
I don't know about anyone else but I would not attempt to use aluminum conduit in any underground installation. Section 344.10(B)and 300.6 permit the installation. However, since the corrosion protection must be approved and there is no product that is listed, the AHJ must approve the protection scheme.

Now for aluminum conduit to the gas pumps. 514.8 and even Exc. 2 prohibit its use. :D
 
Re: aluminum conduit - uses permitted

I don't think 514.8 prohibits aluminum RMC. It doesn't specify material. It does require IMC to be steel.
The requirement is the same in 501.4(A)(1)

edit: hit send too soon

Not my area of expertise. I've never had anyone propose to use aluminum RMC. I bet rbalex would have something to say on this.

[ October 07, 2005, 12:39 AM: Message edited by: sandsnow ]
 
Re: aluminum conduit - uses permitted

Originally posted by charlie:


Now for aluminum conduit to the gas pumps. 514.8 and even Exc. 2 prohibit its use. :D
Click to expand...
Hmmm...I thought that 'threaded rigid metal conduit' could either be ferrous or non-ferrous. 514.8. yes/no ?
 
Re: aluminum conduit - uses permitted

Originally posted by jimwalker:
Like always its price gouging and using katrina to justify it
Click to expand...
Jim, maybe you missed it many chemical industries in the area had to shut down for several weeks. Do you actually have any real evidence to prove price gouging is involved? I doubt it. :roll:

[ October 07, 2005, 02:59 PM: Message edited by: peter d ]
 
Re: aluminum conduit - uses permitted

Last year I had to replace the conduit and wiring to submerged pumps at a UST because they used aluminum conduit. The conduit corroded in the submerged pump sump to the point the wires were exposed before the sealoff. This conduit was not in contact with the ground, but the sealoff is steel and the conduit aluminum... dissimilar metals?
 
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