New Polebarn Power feed

[jg4660]

Hi All,

I just put up a 24x32 polebarn and now am going to get some power to it. I was hoping some of the electricians in the group can check my plans.

I have a 150A main panel in the basement of my house, i plan on running about 90' of 2-2-2-4 SER cable from a 90A breaker through the basement and then transition to 2-2-2-4 URD in an outside juction box on the house and then direct bury that about 30' into the barn and connect to a 100A main panel. Will add 2 ground rods at the barn 6' apart and connect both with #2 bare ground and into the panel.Will use conduit where the URD comes above ground and into the panel in the barn.

A couple questions-

Whats the best way to splice the two different wires together? and to connect to the ground rod wire mechanical lug or crimp?

Will i need an adapter to connect the neutral and ground wires in the main panel?

Does all this sound about right or is there a better way? Anything else i'll need?

Thanks in advance!
JG

 

[wyliesdiesels]

URD is NOT allowed inside structures.

#2 is way overkill for the GEC for the rods.

Use solid #6 cu.

Make sure to isolate the neutral bar in the subpanel which may require the purchasing of a separate ground bar kit.

 

[jg4660]

Yep..The URD will all be outside except for the run in conduit to the panel in the barn.

Thanks

 

[mm08822]

URD is NOT allowed inside structures.

#2 is way overkill for the GEC for the rods.

Use solid #6 cu.

Make sure to isolate the neutral bar in the subpanel which may require the purchasing of a separate ground bar kit.

Yep..The URD will all be outside except for the run in conduit to the panel in the barn.

Thanks

That's the part that's a nope.

Consider MHF or pipe it point to point and use xhhw Aluminum.

 

[wyliesdiesels]

Yep..The URD will all be outside except for the run in conduit to the panel in the barn.

Thanks

That will not be code compliant.

Doesnt matter that its in conduit.

Conduit does not change the insulation rating which prohibits its use indoors.

 

[mike93lx]

Yep..The URD will all be outside except for the run in conduit to the panel in the barn.

Thanks

Please listen to these guys. You have decades of experience for free here.

 

[jg4660]

Ok..Gotcha. So i'll use MHF from the junction box on the outside of the house piped where above ground and to the panel in the barn. Thanks for clarifying that, didn't realize URD couldn't be used inside in conduit.

Thanks
JG

 

[mike93lx]

Ok..Gotcha. So i'll use MHF from the junction box on the outside of the house piped where above ground and to the panel in the barn. Thanks for clarifying that, didn't realize URD could be used inside in conduit.

Thanks
JG

If you run conduit inside the house, you could use MHF end to end and avoid the splice.

If you keep the splice, Polaris connectors or split bolts are popular. Box size is set by conduit size, IIRC. So going big on the conduit will mean a very large box

 

[jg4660]

Yea i thought of piping inside the house but the cable costs me about the same minus the extra labor of piping so i decided against it.

So what is URD used for if it cant be brought inside..pole to pedestal only huh?

JG

 

[mm08822]

Yea i thought of piping inside the house but the cable costs me about the same minus the extra labor of piping so i decided against it.

So what is URD used for if it cant be brought inside..pole to pedestal only huh?

JG

Correct - pole to ped, pole to meter, pad to ped, pad to meter where peds and meters are outside.

UNDERGROUND Residential Distribution cable.

 

[mm08822]

Yea i thought of piping inside the house but the cable costs me about the same minus the extra labor of piping so i decided against it.


JG

Jbox and terminations cost money and labor. Splices may one day become problem. For certain if they dont exist they arent a problem.

Could possibly even run conduit through foundation and never see any conduit/fitting.

 

[jg4660]

Thanks everyone...I think i got it straight now. Just need a source for MHF by the foot.

 

[pattenp]

If not doing direct bury you can use XHHW-2. MHF is a direct bury cable.

 

[jg4660]

One last thing...Where the 2-2-2-4 MHF comes above ground what size conduit should i use 2''? and how about the size of the junction box, i'll have the 2'' (or ?) MHF conduit coming in the bottom and the 2-2-2-4 SER cable coming into the back, how should that enter ser clamp seeing it won't be in conduit. So i need space to splice 3 #2's and 1 #4.

Thanks
JG

 

[mike93lx]

For just protection, 2" is way overkill. 1.5" is plenty and I think 1.25 would work..not sure on the fill.

For a full run I would advocate 2" to make the pull easier,but depending on the number of bends, 1.5" would probably work fine too

 

[jg4660]

I think 1.5'' should be fine too...how about the junction box size?

 

[mike93lx]

I think it is 6x the conduit size, which is why keeping conduit small can help

https://www.ecmweb.com/code-basics/sizing-junction-boxes

 

[sparky 1971]

I would check with your local inspector. Around my area in cases like this, they let us stick the urd into the panel for a sub panel. If not, I know j-boxes have already been mentioned. If it were me, I think I would use a 3R disconnect back to back with the panel then run THHN into the building. In my opinion, it would look better even though it costs more.

 

[sparky 1971]

Or, how about a Quazite type hand hole close to the barn. You could make your transition from urd to thwn or xhhw there and run a minimal amount of pvc to the barn. No ugly boxes on the wall.

 

[mike93lx]

Or, how about a Quazite type hand hole close to the barn. You could make your transition from urd to thwn or xhhw there and run a minimal amount of pvc to the barn. No ugly boxes on the wall.

URD is more expensive than MHF and running MHF requires no transitions at the barn, as long as the wire is in conduit to the panel.

Makes no sense to use URD, IMO

 

[sparky 1971]

URD is more expensive than MHF and running MHF requires no transitions at the barn, as long as the wire is in conduit to the panel.

Makes no sense to use URD, IMO

I didn't pay attention to the other posts suggesting mhf. I have never heard of it before.
Is it something fairly new or have I just been missing out all these years?a

Edit. Nevermind. I just looked it up. I have seen it but didn't realize it was different than urd. I even used it on a job a coup!e of weeks ago,
but the customer supplied it. I just figured it was a different brand of quad urd than I was used to.