junction box/enclosure questions

[jpcjguy]

Hi all,

So I am mounting a NEMA 3R enclosure on the outside of my attached garage.
This is where my main power 2/0 aluminum XHHW from the detached will transition to 1/0 copper to go to my panels, which are on the other side of the wall (behind the meter box). This is in the 2.5" conduit.
The other 2 conduits are for future plans (screen porch and possible pool). The thought is to put them in the trench and under the house in the crawlspace so I don't have to dig this area up again.
My inspector said to transition to 1/0 copper SER in the enclosure and run that into the panel. (I will be cutting a section of drywall out in the garage to run the wire). The plan is to use some polaris connectors in the enclosure.

My questions:
Is there a minimum/maximum height from the ground of the enclosure?

Are there spacing requirements of the holes for the conduits coming up from the ground?

Are there any spacing/size requirements of the holes in the back that will go to the panel? Any special fittings required?

Thanks!

 

[sberry]

I am curious again,,, why transition to copper?

 

[jpcjguy]

I am using 2/0 aluminum to the junction box from the detached garage. The 125A breaker will only fit a 1/0 wire. So I am transitioning to SER to run in the walls, and was recommended to transition to copper in 1/0 to keep the same "size rating" as the 2/0 aluminum XHHW...

 

[sberry]

How far is the short wire? The reason its upsized is for distance, its less of an issue on short sections.

 

[jpcjguy]

How far is the short wire? The reason its upsized is for distance, its less of an issue on short sections.

3-5 feet range. See the attached pics. The new junction box will go where the current phone line box is. The inside panels are on the other side of the meter.

 

[sberry]

5 ft of 1/0 wont mean squat here, use similar wire. Wayyyyyyyyy over complicating this.

 

[jpcjguy]

I have to drop from 2/0 to 1/0 regardless - to fit the breaker - suggestions?

 

[sberry]

Use 1/0 alum.

 

[Bert_]

What size are the other conduits? Just the 2.5" conduit it's going to require a pretty large box. I think 18"x18" is the closest common size that is large enough.

Can you come right into the back of the panel and eliminate the pull box?
I don't think I've seen a 125A breaker that doesn't take 2/0.

 

[jpcjguy]

What size are the other conduits? Just the 2.5" conduit it's going to require a pretty large box. I think 18"x18" is the closest common size that is large enough.

Can you come right into the back of the panel and eliminate the pull box?
I don't think I've seen a 125A breaker that doesn't take 2/0.

Inspector told me 18x18x6 box. Sticker right on the side of the 125A breaker says "1/0 MAX"

 

[jpcjguy]

So I am ready to mount the box. There will be the following conduit going to it:
2.5"
2"
1"

In the picture, the yellow line is the bottom of the panels inside. I was planning on mounting the junction box so the top is a couple inches below that line.
This way when I go out the back of the box, I make a right turn and then I am under the panels and go up.

As you can see there will be two 90 degree turns up to the junction box. I will be pulling the wire from the garage. Should I assemble all the PVC and pull the wire all the way? or should I pull the wire to the first 90 (corner of the building) and then assemble the last 5 feet or so over the wire?
I am hoping that three 2/0 and one #4 (aluminum XHHW) should not be too bad to pull in 2.5" conduit....
Looking for any tips, suggestions! Never pulled this size wire 215 feet before!