I have to "sleeve" 100 amp al. SER (3 #2, 1 #4) for physical protection. (TODAY!) I will need to run it through a PVC LB.
I would like to keep the piping as small as possible, but I'm afraid a 1 1/2" LB will be too tight.
Any (quick) help out there?

If 2" isn't too big for any reason other than asthetics, I've often found that 2" is cheaper than 1-1/2", simply because they sell so much more of it.

Getting SER through an LB a few too many times has convinced me that it's cheaper to pipe all the way and use PVC and RHW-2, plus the installation lasts much longer.

You can use a 2" LB with 1 1/2 PVC just buy a reducer. The amount of time and effort you will save over struggling to get the SER into the 1 1/2 LB will be worth it.

Duuuh!
A reducer! I can't believe I didn't think about it.

Thanks, guys

I know its common practice to use larger LB with reducers and have done that many times myself, but how are you going to support the LB? The conduit is only permitted to support conduit bodies of the same trade size as the conduit. See 352.10(H) for rigid nonmetallic conduit and Exception #1 to 314.23(E) for rigid, IMC and EMT.
Don

What I'm doing is running an SER feeder through the basement and crawl space of a 1st floor unit, out the wall and up into the second floor to feed the panel.
I am using the PVC (about 12' with an LB at each wall penetration) for some physical protection.

Ah well, 2" it is.

[This message has been edited by Redsy (edited 09-10-2002).]

Job done.
2" -- fairly easy.
1 1/2" would have been a mistake.

I usually run a screw through the back of the LB into the wood sheething of the house. Not sure if its legal but it works well especially when I am trying to get the SER or SEU into the house. It adds a lot of stability to the LB.

tsolanto,

Using a screw in the back of the LB. I was doing that for many years. It works well, and I am not sure if it is against the code. I wouldn't fail that job if I was inspecting. After all the pipe is there just to protect the wire from damage.

Art. 370-23 of the 1999 Code does not address the use of screws. Art. 370-23(b)(1) addresses the use of nails, and "they shall pass through the interior within 1/4 inch of the back or the ends of the enclosure." However, I would prefer screws as they would not pull out as easily as nails. IF one considers the LB as an enclosure, then par. (e) would not allow screws or nails, but requires support within 3 feet of the enclosure. I must assume the Code means a strap support, and that would be my preference. In any case, the local AHJ has the final say.

Warren1 how do you strap an LB?

I actually screwed an LB once, but I wasn't comfortable about it.
I'm thinking doing so would violate 110.3(B)

tsolanto
My intention was to say that the conduit on each side of the LB, or enclosure would need to be strapped within three feet.
Guess I need to re-read my post to see if it make any sense, HUH.

never mind

[This message has been edited by Redsy (edited 09-13-2002).]

Don — in your 8/10 posting about need for independent {other-than-raceway} support in the case of using reducing bushings, wouldn’t drilling bolt holes in most {all?} cases constitute modification of the conduit body? I am not aware of conduit bodies furnished with lugs or other mounting means.

Can you or another suggest possible resolution to this? [I understand and do not object to the requirement for additional support.] Thank you for your time. —bjarn

I take it to mean, like Warren pointed out, that the conduit itself must be supported within 3' of the condulet if the condulet is over-sized with reducers connecting the conduit.

Make sense?