Underground PVC size transition

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Coppersmith

Coppersmith

Senior Member
Location
Tampa, FL, USA
Occupation
Electrical Contractor
Have a weird situation I'm not sure how to code compliantly solve.

An additional garage with 60 amp subpanel is being built about 100' away from the existing garage where the main panel is located. A 1-1/4" PVC was stubbed up in the slab below the subpanel and out the side at the required 18" depth. GC hired a directional boring company to come in and install a pipe under the very wide driveway between the garages. Instead of putting in a 1-1/4" PVC pipe, they put in a 2" PVC pipe. Now I have to mate the 1-1/4" to the 2" without any junction box, hand-holes or anything else that would be visible.

I thought about sliding a run of 1-1/4" PVC through the 2". (It's a straight run that gently arcs downward and then back up.) The bell end of the 1-1/4" just fits inside the 2". Decided this would be a bad idea because the pipe might get stuck if the pipe flattens out somewhere.

I thought about using plumbing transitions but that's a code violation as far as I know.

My best solution so far to glue bell end of the 1-1/4" inside the 2". There's about a 1/16th" gap. Not sure if this is code compliant.

Thoughts?
 
Coppersmith said:
Still curious if this is legal.
Click to expand...

I have changed sizes between 3/4" and 1" in a run. A 3/4" bell-end fits perfectly inside a 1" bell-end and snakes easy.

As far as the code ... well there is nothing that says you cannot, and the fitting I linked to should be listed for the application.

As always the code is a minimum and working down to it may result in a PITA.

Any reason not to just run 2" all the way?
 
iwire said:
I have changed sizes between 3/4" and 1" in a run. A 3/4" bell-end fits perfectly inside a 1" bell-end and snakes easy.

As far as the code ... well there is nothing that says you cannot, and the fitting I linked to should be listed for the application.

As always the code is a minimum and working down to it may result in a PITA.

Any reason not to just run 2" all the way?
Click to expand...
I think you'll find what works on 3/4 & 1/2 won't work on the larger trade sizes.

Sent from my SAMSUNG-SM-G870A using Tapatalk
 
iwire said:
That would do it.:D

So maybe 1.25 from there to the section of 2" and stay with 2" there after?
Click to expand...

That would work.

Besides, for a 60 amp feeder, 2 #6, 1 #8 and 1 #10 will fly through a 1.25" conduit like greased lightning, even with the transition.
 
iwire said:
So maybe 1.25 from there to the section of 2" and stay with 2" there after?
Click to expand...

The reasons I don't want to run 2" on the other end are:

1) I had to add a subpanel on the main panel side because panel was full. Biggest KO on subpanel is 1.5".

2) I have to core drill through a concrete filled block wall. I hate core drilling and the larger the size, the more I hate it.

3) Pipe is going to be exposed inside garage for about 15' and I had a hard enough time trying to sell this idea with 1.25". Pretty sure 2" would be a no go. Plus it's snaking behind the legs of a storage cabinet. 2" may not fit there. If I were to come through the wall just below the subpanel it would look a lot nicer but would require trenching 20 feet in a very bad area (full of bushes and other pipes).
 
Coppersmith said:
The reasons I don't want to run 2" on the other end are:

1) I had to add a subpanel on the main panel side because panel was full. Biggest KO on subpanel is 1.5".

2) I have to core drill through a concrete filled block wall. I hate core drilling and the larger the size, the more I hate it.

3) Pipe is going to be exposed inside garage for about 15' and I had a hard enough time trying to sell this idea with 1.25". Pretty sure 2" would be a no go. Plus it's snaking behind the legs of a storage cabinet. 2" may not fit there. If I were to come through the wall just below the subpanel it would look a lot nicer but would require trenching 20 feet in a very bad area (full of bushes and other pipes).
Click to expand...

In that case, I would install the pull line before backfill as suggested, and use the reducers.
 
Well, first of all if I am understanding your installation you're taking a 60 amp service out to a detached garage that is 100 feet away. If in fact this is true then your trench should have been at 24 inches and not 18 inches.
And because it is a detached garage you will need a main breaker as a means of disconnect in your panel.
 
electrict dave said:
Well, first of all if I am understanding your installation you're taking a 60 amp service out to a detached garage that is 100 feet away. If in fact this is true then your trench should have been at 24 inches and not 18 inches.
And because it is a detached garage you will need a main breaker as a means of disconnect in your panel.
Click to expand...
You don't necessarily need a main breaker because you can still use the 6 disconnect rule.
 
What is the length of the 2" 'sleeve'?

As I understand it, the reason you can't simply slide some 1.25" through the 2" sleeve is because of the bell ends for joining lengths of 1.25". But if you had a long enough length of 1.25" you would have no problem, correct?

Would a flexible NM raceway be suitable for the entire run, something continuous with no joints in the middle?

-Jon
 
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