Aluminum or Rigid Steel

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The only problem I have ever had bending AL conduit was if you use a standard hand bender. It seems you can't get a consistent radius. But if you use a chicago or sidewinder type you should be ok. As far as wire pulling problems the only one I have ever had was a bent hook on a fish tape digging in to the conduit. This was solved by installing a leader or taping and soaping the end.
 
Nice to know that Aluminum is cheaper now. I would always choose the IMC. In some ways its a pain to work with but it is so much cheaper and lighter than Rigid you just cant resist.
 
Corrosion Resistance

Corrosion Resistance

Does standard rigid aluminum conduit come with corrosion protection or would this be an additional requirement? Only for when the conduit passes thru concrete floor / wall penetrations because of the reaction with the aluminum and concrete. I guess you could also provide a link-seal of some type between the conduit and the concrete also.
 
Mike01 said:
Does standard rigid aluminum conduit come with corrosion protection or would this be an additional requirement? Only for when the conduit passes thru concrete floor / wall penetrations because of the reaction with the aluminum and concrete. I guess you could also provide a link-seal of some type between the conduit and the concrete also.
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I wouldnt use aluminum underground or encased in concrete, thats what PVC is for....
 
wireman said:
Maybe "stretch" is the wrong term, but what we noticed was that it was difficult to match bends even from the same bundle of pipe. We had some expert conduit men and everyone had trouble with it.
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Al is a bear to run because the hardness of the conduit varies so much which makes each piece spring back differently.

Running rigid Al is almost an art in itself, especially when you have to justify the scrap.

Forget all the fancy benders. With Al, a real Chicago bender is your friend and a 'Porta-Pony' is worth it's weight in gold.
 
Mike01 said:
Just curious what others opinions are, Rigid Aluminum conduit in leau of Rigid Steel? What are the advantages / disadvantages from what I can find Aluminum is lighter and therefore easier to install, however does not have the wall thickness or a Rigid Steel Conduit. Just curious there is a project where the contractor has suggested aluminum conduit in leau of rigid as a potential cost savings other than the wall thickness is there any other advantage / disadvantages?
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Aluminum offers better corrosion resistance than GRS in certain areas, such as water treatment facilities.

Since the extrusion process offers a smoother surface than the GRS, pulling conductors through it should be easier.

Installation cost is less, but it is only meaningfull on large jobs where thousands of feet are installed.

Impact resistance may be different from GRS.
 
K8MHZ said:
Al is a bear to run because the hardness of the conduit varies so much which makes each piece spring back differently.

...
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I find that true of any conduit... even swings with the temperature. But yes, aluminum has a wider range than steel... but it is also easier to "fix" ... :grin:
 
wireman said:
Maybe "stretch" is the wrong term, but what we noticed was that it was difficult to match bends even from the same bundle of pipe. We had some expert conduit men and everyone had trouble with it.
Click to expand...

Al is a bear to run because the hardness of the conduit varies so much which makes each piece spring back differently.

Running rigid Al is almost an art in itself, especially when you have to justify the scrap.

Forget all the fancy benders. With Al, a real Chicago bender is your friend.
 
aluminum conduit

aluminum conduit

As all of the previous post have pointed to the advantages and disadvantages of Aluminum conduit one particular plus with aluminum is the lack of inductive reactance with a non ferrous material and the added benefit of less voltage drop for the same given distance in steel conduit.
 
Mike01 said:
Does standard rigid aluminum conduit come with corrosion protection or would this be an additional requirement? Only for when the conduit passes thru concrete floor / wall penetrations because of the reaction with the aluminum and concrete.
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If your that far into the construction that your using this material, wouldn't your think that this would have been implyed in part by using standard UL wall / floor penterations details?

Most details I've ever seen, the hole is bigger than the conduit and isolated with filler material and sealed accordingly.
 
I've run a lot of 3 1/2" aluminum by myself. I can't say the same for steel.
As for bending, the 881 doesn't care what it's bending. Segment bending w/ an 884 or 777 can be a little inconsistent, but not bad.
I have had the pleasure of running aluminum for about 10 years now. I like it for sizes 1 1/4' and up.
Wire pulls have never been a problem.
 
RGS vs Aluminum

RGS vs Aluminum

In refineries, chemical plants, offshore vessels, offshore platforms, fibers plants, grain silos and tobacco plants we use aluminum by the thousands of feet underground and aboveground. Rarely do we see rigid galvanized conduit, its expensive, especially when buying fittings, and its fault current carrying capability is better than the wire in it.

I have been in electrical industry 48 years and wouldn't even consider RGS anymore.
 
weressl said:
Since the extrusion process offers a smoother surface than the GRS, pulling conductors through it should be easier.
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I've also heard its harder to pull through. I think it may be the smoother surface that makes it that way. More surface area of the wire contacts more surface area of the conduit, making more friction.

In steel conduit, the wire probably rides more on top of the bumps.

Steve
 
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