direct burial cable penetrations

[D Wood]

Hello all, newbie here:grin:

I cannot come to a definitive answer using the NEC to find out the following question. And I did try to search for old posts but I must say that I suck at googling things.

When a direct burial cable is run outdoors and comes to a building to which it has to penetrate to continue on to the control board inside the building - how far can that db cable legally run indoors before it must be "converted" to a standard cable type?

I have 50' stuck in my head but am having a bugger of a time finding it in my '08 book.

Any assistance is greatly appreciated and thanks in advance.


Dave

 

[shepelec]

Are you talking about USE?

 

[D Wood]

If that's an acronym; please advise. If you mean use as in I want to use the db cable and need to know how far in the building I can penetrate, yes this is what I am after.

 

[iwire]

If that's an acronym; please advise. If you mean use as in I want to use the db cable and need to know how far in the building I can penetrate, yes this is what I am after.

We cannot give an answer without knowing the cable type.

It is not enough to say it is 'DB'.

If it is type 'USE' it cannot enter the building at all.

If it is say Type 'USE / RHW' it can be run as far as you want inside a raceway.

 

[jumper]

If that's an acronym; please advise. If you mean use as in I want to use the db cable and need to know how far in the building I can penetrate, yes this is what I am after.

USE=Underground Service Entrance. Regular USE cannot enter a building, 338.12(B)1; however, dual rated USE/RHH/RHW may.

Here is a link:
http://www.southwire.com/products/RHHRHWUSEOEM.htm

Can you clarify your db cable and what your app is?

Where you penetrate the building may decide the length and disconnect location.

( As usual, I am one step and 5 minutes behind Bob)

 

[don_resqcapt19]

In general the only places the code uses the 50' permission to extend a outdoor or directly buried cable into the building is in Chapters 7 and 8.
If this cable is not covered in those chapters, it must be a cable that is rated for both direct burial and use within a building. If it is not rated for both conditions, it can't enter the building. It must be spliced at an exterior junction box to a cable that is suitable for use in the building.

 

[jusme123]

In general the only places the code uses the 50' permission to extend a outdoor or directly buried cable into the building is in Chapters 7 and 8.
If this cable is not covered in those chapters, it must be a cable that is rated for both direct burial and use within a building. If it is not rated for both conditions, it can't enter the building. It must be spliced at an exterior junction box to a cable that is suitable for use in the building.

would the interior cable that you are splicing to have to be rated for wet location?

 

[winnie]

And if by 'direct burial' cable you mean 'UF' cable ('direct burial romex'), then this stuff is also rated as NM, and can be used indoors in exactly the same ways as NM. It is more expensive and harder to work with, but there is _no_ requirement that you change over from UF to a more standard indoor wire.

-Jon

 

[don_resqcapt19]

would the interior cable that you are splicing to have to be rated for wet location?

It would have to be rated for a wet location if it is installed in a wet location. The current code rule in 300.9 does not say that the interior of an enclosure installed in a wet location is wet location.

Charlie Trout, in a recent code question of the day, said he thinks the interior of an enclosure installed in a wet location is also a wet location. I am not sure that I would agree completely, but it is my opinion that any conductors installed in a NEMA 3R enclosure, below the live parts are conductors installed in a wet location.

 

[tom baker]

And a the NEC requires a raceway for your DB cable that extends past the building footing to the interior and up thru the slab.
300.5(A)