Underground electrical question

[chrisntam]

Working on my shed, digging the trench for my little retaining wall this darn conduit is in the way. If it was perpendicular to the structures, no problem, I could work around it. But it’s on a diagonal.

I called the electrician, he can’t come out until next week, I’d like to get it done sooner. It needs to be about 12” to 18” deeper than it is now, so the wire will have to be lengthened. It’s just one run of 110 to an outlet.

Shed was prolly installed in ‘85, the wire looks like regular old romex. Thinking about doing it myself. J-box up in the attic or hang it off the brick wall? I’d also like to make the run perpendicular to the structures.

I haven’t ran electrical underground before but I have replaced switches, outlets, fans etc.

How would you approach this? The conduit/wire just needs to be deeper. Not enough slack in the wire to make the additional depth. It’s metal conduit on the brick, pvc in ground and to the shed.

Here are some pics.

[EightFingers]

Definitely a homeowner job with the premade bends.

Cut it out and start over.

[fredhargis]

I guess there's not enough length inside the shed to put a J box inside it, so the alternative are your choice. You could put a box down low on the brick and put an outlet in it to make it look like it was done on purpose. You can also get an undergound splice kit (I got one at Menards when I accidentally cut the feed to my barn. These things are actually really robust, the heat shrink that seals it is amazing.

[TDKPE]

Shed was prolly installed in ‘85, the wire looks like regular old romex.  Thinking about doing it myself.  J-box up in the attic or hang it off the brick wall?    I’d also like to make the run perpendicular to the structures. 

Regular old Romex is not rated for wet locations, and anything underground is considered a wet location.  Strip it out, redo the conduit as needed (Schedule 80 where it comes out of the ground, by the way), and pull THWN stranded conductors, which are listed for wet locations.  


It's such a short run, it's not worth trying to salvage what shouldn't be there in the first place.

[cams2705]

Do you actually need power inside the shed?  If not, why not just pull new wire as another poster above suggested, but to an exterior box mounted on the side of your house with a GFCI and not worry about running anything underground.  You can use an extention cord when you're out there an need power.

On a similar note with the retention between the house and shed ... can you pack some crushed "2B" stone in that area?

[srv52761]

1. I will assume it it gfci somewhere upstream as it is not in the shed and it is required to be.
2. That does indeed look like nm-b (romex).  nm-b is not allowed in wet locations, so anywhere outside is a no-no.
3. looks like 1/2” conduit. 12/2wg  nm-b is 0.450” wide, so you need 3/4” conduit, 
4. You are correct, conduit needs to buried 18”. 

It looks like you may need to start in your attic.  
Pull the romex, pull the conduit.
use thwn or uf-b
use 3/4” pvc conduit edit:1/2” is fine if using thwn, but using uf let’s you direct bury 12” and let’s you follow your new grade.

If you use uf-b and you add gfci protection in the house, you can stub the conduit in the ground and direct bury the uf 12” below grade, then stub it up the shed wall and add an lb. If you use conduit you need to go that 18”.  With your sloping dirt, that means about 24-30” at the house to get the 18” at the shed.

edit: Dang, I type too slow.... Tdkpe already said this.....

[TDKPE]

edit:  Dang, I type too slow.... Tdkpe already said this.....

Yeah, but you said it better.  

[Willyou]

Move the outlet in the shed so that it is directly across from the conduit on the house. Then, the crossing will be perpendicular and you will have enough cable length to make it deeper. If you must have the outlet in the existing location, terminate the new crossing at a junction box and then run a short length of new cable from the new junction box to the existing outlet.

[WoodCzech]

Could you go with a galvanized metallic conduit underground?  That, I believe, requires to only be buried 6" deep.

[fixtureman]

Why not put the ell at the roof and the into the shed.