Splicing Wire in conduit below slab.

[SamsTLC]

I am wiring an extension to a school building. The Front portion of the building, which had the original MDP has been demolished to make place for a new larger two-story structure. I am installing a new MDP that will be about 20' away from where the original MDP was.
The entire facility is slab on grade. When the GC demolished the original slab and when we removed the old MDP, all underground feeder conduits had to be cut. Also, as they were digging for footings some more conductors were broken and cut.
My question is this: Is there a legal way to splice conductors running through conduit below grade without leaving access?
repairing the conduit and refeeding new conductors would not be cost-effective since some of the feeders are over 400' long, while I need to extend these wires 50' at most.

 

[LarryFine]

Welcome to the forum.

My question is this: Is there a legal way to splice conductors running through conduit below grade without leaving access?

Simply put, no. You would need at least covered floor boxes.

repairing the conduit and refeeding new conductors would not be cost-effective since some of the feeders are over 400' long, while I need to extend these wires 50' at most.

Is there any place closer, a wall or room, where you could turn the conduits up into boxes?

 

[SamsTLC]

Welcome to the forum.


Simply put, no. You would need at least covered floor boxes.


Is there any place closer, a wall or room, where you could turn the conduits up into boxes?

Thank you! Been referring to the forum for years now. Never communicated...

Terminating in a JB on a wall is an option I brought up. Customers preferred not since we will have at least 6 of these Junction boxes in various hallways or classrooms. if I have no choice, that's what I will probably do.

It is interesting that direct burial wires can be spliced with no box (300.5(E)) while conduit cannot. I guess the assumption is that wire in conduit is expected to have the option of being pulled or re-fed, while direct bury wires are not.

Thanks

 

[LarryFine]

Terminating in a JB on a wall is an option I brought up. Customers preferred not since we will have at least 6 of these Junction boxes in various hallways or classrooms. if I have no choice, that's what I will probably do.

What about within a wall, like an empty panel enclosure?

It is interesting that direct burial wires can be spliced with no box (300.5(E)) while conduit cannot. I guess the assumption is that wire in conduit is expected to have the option of being pulled or re-fed, while direct bury wires are not.

Direct-buried cables (and splices) are considered accessible.

Plus, splices don't "fit" where continuous conductors do.

 

[SamsTLC]

What about within a wall, like an empty panel enclosure?

Yes. That would be the idea.

Direct-buried cables (and splices) are considered accessible.

Plus, splices don't "fit" where continuous conductors do.

Direct burying splices with no marking under the earth is a very loose interpretation of accessible. To that end I can argue that a Romex splice buried in sheetrock is "accessible" All a person needs to find it is a hammer and some time... (time to rip all walls out)

Anyway, I get your point. Thanks for your Help!

 

[roger]

To that end I can argue that a Romex splice buried in sheetrock is "accessible" All a person needs to find it is a hammer and some time... (time to rip all walls out)

That argument wouldn't fly.

Accessible (as applied to wiring methods). Capable of
being removed or exposed without damaging the building
structure or finish or not permanently closed in by the structure
or finish of the building.

 

[Choice_Gorilla]

Is there no engineered drawing that provides information for refeeding the new MDP? Can you RFI it? As the for the unintentionally broken/cut conduits, that’s on whoever did it. It’s on you to fix it the right way not the cheap way in my opinion. If that means sawcutting the slab so you can re route conduit and and splice it, then so be it.

 

[kwired]

I am wiring an extension to a school building. The Front portion of the building, which had the original MDP has been demolished to make place for a new larger two-story structure. I am installing a new MDP that will be about 20' away from where the original MDP was.
The entire facility is slab on grade. When the GC demolished the original slab and when we removed the old MDP, all underground feeder conduits had to be cut. Also, as they were digging for footings some more conductors were broken and cut.
My question is this: Is there a legal way to splice conductors running through conduit below grade without leaving access?
repairing the conduit and refeeding new conductors would not be cost-effective since some of the feeders are over 400' long, while I need to extend these wires 50' at most.

did someone hose you or are you trying to fix something you omitted when bidding?

I'm reading you had to cut these feeders leaving a MDP when it was removed from portion of building that was demolished. If they would not have reached the new destination to begin with, then you still have same issues, if they would have reached new destination you probably needed to pull them out of the raceways instead of cutting them. If someone else cut them without your approval - you may have negotiations to make or even a legal battle if others don't want to work with you on it. Can depend on the contract to some extent as well

 

[Another C10]

I'd be surprised if there's a code that allows buried plices

 

[winnie]

1) I question the economy of trying to save the old conductors. How old is the original installation? Did you budget for conductor replacement if it was discovered they were unserviceable?

2) what about putting the splices in an underground vault some smaller distance from the building then the full 400 foot run?

Jon