NEC 300.13 and 300.5

[FionaZuppa]

i need to extend the end of a branch circuit (single phase 50a 240v residential). the run is about 100ft and buried 20" below grade in plastic conduit. its two 6awg and two 8awg wires, need to go another ~15ft. the termination is a small distribution box (one 50a gfi and two 20a gfi's). this is all outside.

NEC Article 300.13 requires mechanical and electrical continuity for conductors in raceways. In other words, you cannot have a splice in a raceway (but you can have it in a box or conduit body that has an accessible cover). NEC Article 300.5 does allow splices in direct-buried conductors. That?s because you can use instruments to locate the splices and you can excavate to get to them. However, it?s much more difficult to do maintenance and inspection on conductors that are in raceways.

but where in 300.5 does it say i can splice?

edit, i suspect i cant........ i guess they mean like a wire that is rated "UF" or the like and is not in conduit/raceway...... is this correct? if this is the case do i have any options w/o pulling new wire? i cant add a box because it wont be accessible.

if buried conductors in conduit get damaged for any reason, can the damaged section be repaired or does NEC force a re-pull of all the wires?

 

[Smart $]

How does the existing load end terminate? I have to believe load equipment or devices are not also buried.

If it stubs up, simply trim back below graded and install a handhole or weather-proof "plastic" box. I believe there is a section which permits boxes below grade, but I don't recall what section that is offhand.

 

[Smart $]

... I believe there is a section which permits boxes below grade, but I don't recall what section that is offhand.

See 314.29.

 

[FionaZuppa]

the load from the distro panel is 50a 240v gfi to a UL listed spa. one 20a 120v gfi to an outlet in spa service area for a sump pump, the other 20a gfi is not used currently but will probably feed some outdoor lighting.

so here's the issue i have. the area at and behind the panel will be a raised planter box (moving box to the corner, etc). "accessible" in NEC seems to have poor definition. could i use a underground rated box, do my splicing, build raised planter wall (block), top the box with gravel to make it "accessible"?? the splicing i have in mind would be using UL listed long barrel splice crimped and soldered, and then 2-3 pieces of UL heat shrink tubing.

 

[FionaZuppa]

what is the dirt/soil considered in a planter box that is ~18" above grade?

and "covered by gravel", how much gravel is allowed? if the junction box is at the bottom of the planter box would it be considered "accessible" under the below definition? i really dont want to re-pull the wires.....

314.29 Boxes, Conduit Bodies, and Handhole Enclosures
to Be Accessible. Boxes, conduit bodies, and handhole
enclosures shall be installed so that the wiring contained
in them can be rendered accessible without removing
any part of the building or, in underground circuits, without
excavating sidewalks, paving, earth, or other substance that
is to be used to establish the finished grade.
Exception: Listed boxes and handhole enclosures shall be
permitted where covered by gravel, light aggregate, or noncohesive
granulated soil if their location is effectively identified
and accessible for excavation.

 

[Smart $]

If the planter box "wall" is going to be CMU's, have you considered embedding a splice box in the wall?

 

[FionaZuppa]

If the planter box "wall" is going to be CMU's, have you considered embedding a splice box in the wall?

it was considered, but dont want a "hole" in side of wall for a box. the wall will be stucco.

i guess its that gray area of "accessible". to me getting down to the box if needed would be "easy", to others it may be "hard".

EDIT: 1sec, a splice box on the inside of the wall?? it would be hidden yet more accessible than being at the bottom of the box?? i guess all i need to do is raise splice box up yet low enough to be covered with gravel/soil.

 

[Smart $]

If you bury a box, don't forget it also has to have a location "marker" at grade (or at surface if under raised planter soil).

I'd say use your discretion on "accessible" because I can't provide any advice beyond Code text.

 

[FionaZuppa]

If you bury a box, don't forget it also has to have a location "marker" at grade (or at surface if under raised planter soil).

I'd say use your discretion on "accessible" because I can't provide any advice beyond Code text.

NEC says

....if their location is effectively identified
and accessible for excavation.

imo, the location is accessible for excavation, be it hand excavation. i would just need to identify the location with a marker in the planter box stating that a splice box is located below.

 

[iwire]

I hate playing find the box.

If it was me there would be a visible box or extend the raceway directly and replace the conductors back to where they could be spliced.

 

[FionaZuppa]

I hate playing find the box.

If it was me there would be a visible box or extend the raceway directly and replace the conductors back to where they could be spliced.

i think it will just be easier to re-pull the wire. a royal pita, but better this way. i can re-use some of what i pull out for the other wires i have to re-pull.

i did this relocate bit with some electrical & water a few months ago, but the pipes were empty. in this case its all live stuff that i have to re-do. thanks.