# Expansion joints for electrical conduit



## CDH (Aug 8, 2009)

I don't know why you would need them in either location.


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## J. V. (Jun 1, 2007)

I have never used them before.


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## hpp58 (Feb 28, 2008)

Above the ground

http://www.ipexelectrical.com/Content/Products/Product.aspx?IsDownload=true&FileId=440


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## darren (Nov 25, 2005)

Like mentioned they go above ground. Make sure when you glue them in place that the expnasion is in the middle(usually has some time of mark) so that it can move up and down.


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## CDH (Aug 8, 2009)

Must be a snow country thing, never seen or heard of them being used in the south.:no:


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## darren (Nov 25, 2005)

I have always used them where PVC came out of the ground and was subject to the earth moveing with the frost.


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## frenchelectrican (Apr 12, 2006)

I have used in quite few spots either in horztonal or vertical fashon for expanding coupling or sleeve.

One is from coming from the ground when you have pretty serious frost level.

Second is I used on very long run on PVC pipes on surface mount { above ground } then I will instal one or more depending on length.

I know they are not cheap but they can justifed the cost to prevent any damage to the conduit or junciton box or meter box which I use them below the meter socket that is one of few spots I expect to see damage there with hevey frost movement.

Merci,.
Marc


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## brjl (Dec 1, 2009)

Thank you for the replies. Once I got thinking about it, it makes sense to place them above groung so they can do what they are designed to do. Again, thanks for the help, doing it yourself is saving me big $$$. Of course, I am having an electrician check all of my work prior to hooking up to the service panel. 

Brian


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## J. V. (Jun 1, 2007)

brjl said:


> Of course, I am having an electrician check all of my work prior to hooking up to the service panel.
> 
> Brian


Thats what they all say. :laughing:


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## teamo (Sep 7, 2008)

I always use them for PVC burials. I always questioned whether I needed them until I saw that the marking line actually changes with the change in seasons. Maybe it's not much of an issue in the warmer southern states but up in the northeast it definitely matters. :thumbup:


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## brjl (Dec 1, 2009)

It makes sense, even though they cost $15 for each, I could just see my schedule forty crack while the ground is heaving. That would end up costing me much more. Better safe than sorry!


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## brjl (Dec 1, 2009)

J. V. said:


> Thats what they all say. :laughing:


My favorite drinking buddy is a master electrician and will work for beer. :thumbsup:


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## hpp58 (Feb 28, 2008)

"Must be a snow country thing, never seen or heard of them being used in the south.:no:"

It's not a snow country thing. It's A "code" thing 352.44. Thermal expansion can be worse in the south that the north.:thumbsup:


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## CDH (Aug 8, 2009)

hpp58 said:


> "Must be a snow country thing, never seen or heard of them being used in the south.:no:"
> 
> It's not a snow country thing. It's A "code" thing 352.44. Thermal expansion can be worse in the south that the north.:thumbsup:


 I don't know how we have made it all these years without them, I've been a lineman for 25 years and have seen hundreds of URD service installations and still regularly work in underground subdivisions and have never seen a problem with conduit without expansion joints in it, for that matter we have hundreds of thousands of feet of conductor buried in conduit from manholes to risers up poles and not 1 expansion joint.:no: Don't know about the code thing as we fall under a different set of rules, but I would have thought the electrician's around here would have if it applied to this area.


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## darren (Nov 25, 2005)

You can actually get expansion joints for EMT as well, i have never had to use one though.


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## Missouri Bound (Apr 9, 2011)

Although they are listed as required in the NEC book, the circumstances where they would be needed in any residential installation would be rare...if not non-existant. Only under extreme temperature changes and excessive lengths are they required, and not in burial situations.


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## hpp58 (Feb 28, 2008)

Its need is more common that you think. The code states an expansion joint “shall be provided” in straight runs between securely mounted items with an expected expansion of ¼”. A 20' straight run that’s mounted on the side of a house with a 40 degree temperature change would require an expansion joint.


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