Xhhn-w or USE and conduit bends?

[jekquist]

My local county inspector said I can use xhhn-w or USE #2 wire for a 100 A sub in my pole barn. Run is total of 145feet 65 feet of that being across the basement. PVC is cheap enough, and I have to run conduit on the inside run so I figured why not do the whole run. I am upsizing to #1 because of threads I have read on here stating #2 AL is only good for 90A. Unless you guys can give me a reason not to.


My other question is about max number of bends. From what I have read the maximum number of bends has to be less that 360 degrees. Is this only for the outside/once it goes underground? The reason I ask is, I need 270degrees to make it look clean and run neatly along the joists. I plan on exiting from the main panel on the side, but can move to the top if needed. Man is that NEC book confusing.


Thanks guys. I would have asked the inspector again but I bet he is sick of my questions.

 

[pattenp]

USE-2 only is not allowed to be installed inside, outside only. Use the XHHW or RHH/RHW-2/USE-2.

360deg between pull points.

 

[jekquist]

Transitions are not included as bends? If so can I use a transition(LB) on the side of the main box?

 

[jekquist]

I might have answered my own questions as a conduit body is considered a pull point. So I should be fine having 270 degrees on the inside to a conduit body then 180 degrees to the next conduit body.

 

[metlmunchr]

An LB would give you a pull point so it would not be included in the 360 degrees.

 

[pattenp]

Also a LB can not be used for a transition point (splice point) because the volume/size is too small to meet code. You'll need at least a 8X8X4 junction box for the splices using #2 wire.

 

[bjcouche]

Yes, 360 degrees between pull points, and an LB is considered a pull point. What you will find is that you cannot pull wire through an LB without pulling the wire out of the LB, then shoving it back in the other side. An LB is too tight of a radius to pull wire through.

Also if you are looking at wire types, the advice thus far is good. If you are going to an electrical distributor (not big box stores) you might inquire about what other wire types they have. Around here you can get THHN/THWN in ALUMINUM, and the wire is pre lubed. Might be able to compare pricing between the THWN and the RHH/RHW-2/USE-2. That's what I used for my shop feed.

Brian

 

[zmaxmotorsports]

keeps your bends as far apart as possible when pulling a wire that big that far.

 

[rburke65]

Yep, 360* of bends can make a tough pull.

 

[Cmreschke]

Also a LB can not be used for a transition point (splice point) because the volume/size is too small to meet code. You'll need at least a 8X8X4 junction box for the splices using #2 wire.

Debateable. If it's sized accordingly it can be used as a junction.

 

[theoldwizard1]

I am upsizing to #1 because of threads I have read on here stating #2 AL is only good for 90A. Unless you guys can give me a reason not to.

Sure $$$ !!! You will never miss those 10A !

2-2-2-4 MHF cable is usually the best "bang for the buck". It must be run in a conduit when indoors.

 

[pattenp]

Debateable. If it's sized accordingly it can be used as a junction.

Well yeah if you use conduit that is way over sized for the wire and have a huge LB. Otherwise you'll be hard pressed to meet the dimension requirements of the box to the conduit size for the splice and have the needed lengths of tails to meet code for the splices and be able to shove it in the LB. Also the LB has to be stamped with a volume to be used for splices.

 

[jekquist]

Sure $$$ !!! You will never miss those 10A !



2-2-2-4 MHF cable is usually the best "bang for the buck". It must be run in a conduit when indoors.

I was quoted #1al xhhw-2 for 30 cents a foot. That is well within my budget. Running a welder, plasma cutter and a big compressor I might need those extra 10A.

 

[pattenp]

I was quoted #1al xhhw-2 for 30 cents a foot. That is well within my budget. Running a welder, plasma cutter and a big compressor I might need those extra 10A.

You'll find that buying the individual wires are cheaper than the assembled MHF cable. Another thing is MHF doesn't come in #1, it's #2 or #2/0 or #4/0.

 

[jekquist]

Sounds like my plan is good. Thanks guys I believe I'm on the right track now.