In-Ground Junction Box Shock Hazard

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Ravenvalor

Senior Member
Hello,

Should one be concerned about an in-ground, bottomless, junction box filling up with water thus becoming a shock hazard? If so, would making sure that the circuit inside the junction box was GFCI protected negate that possibility?

Thanks,
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Hello,

Should one be concerned about an in-ground, bottomless, junction box filling up with water thus becoming a shock hazard? If so, would making sure that the circuit inside the junction box was GFCI protected negate that possibility?

Thanks,
Is there an open connection inside the junction box? If there are just wires passing through it the wires would be required to be waterproof anyway so there would be no issue.
 

Ravenvalor

Senior Member
Is there an open connection inside the junction box? If there are just wires passing through it the wires would be required to be waterproof anyway so there would be no issue.

There is an open connection inside the junction box. There are 3 - UF cables spliced together. They are spliced together with regular 3m wirenuts. The junction box is located about 2' away from a patio so I can imagine that people are walking in the vicinity barefooted.

Thank you
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Splice has to be made per 110.14 B, IE listed. WP wire nuts are not listed for UF cable, the splicing means must cover the jacket on both cables.
That makes sense for a direct bury splice, but if it's in an underground junction box, does that still apply?

Cheers, Wayne
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Splice has to be made per 110.14 B, IE listed. WP wire nuts are not listed for UF cable, the splicing means must cover the jacket on both cables.
Wire connectors or splicing means installed on conductors
for direct burial shall be listed for such use.

I wonder if this means that splices on conductors listed for DB require connectors listed for such use, or if it means that conductors that are buried have to use such connectors. It would seem illogical to require such connectors where cables suitable for DB are not buried, but the way this is worded is screwy.

I wonder if there is a definition somewhere that says if an underground box is considered DB or not.
 

tom baker

First Chief Moderator
Staff member
Db wire nuts have a crush strength but are filled with the same gel as the WP ones. I have installed hundreds and never had one fail. The rules for handholes are in 314.30. Splices inside must be listed for wet locations, so just a WP wire nut. Now as pointed out above, its not clear whats required for UF splices in a handhole.
There is a definition of handhole in Art 100.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
There is a definition of handhole in Art 100.
Handhole Enclosure. An enclosure for use in underground
systems, provided with an open or closed bottom, and sized to
allow personnel to reach into, but not enter, for the purpose of
installing, operating, or maintaining equipment or wiring or
both.
That would seem to suggest anything in the handhole is "underground" but does not address the direct burial question. I am inclined toward the idea that something electrical is not buried unless it is directly covered by dirt or some other similar material such as sand or gravel. Can a handhole be itself buried?
 

Ravenvalor

Senior Member
Splice has to be made per 110.14 B, IE listed. WP wire nuts are not listed for UF cable, the splicing means must cover the jacket on both cables.

So the wirenut must be long enough to cover the conductors whether they or insulated or not in order to protect them from the moisture and dirt? The only thing exposed should be the cable jacket?

Thanks,
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
I wonder if this means that splices on conductors listed for DB require connectors listed for such use, or if it means that conductors that are buried have to use such connectors. It would seem illogical to require such connectors where cables suitable for DB are not buried, but the way this is worded is screwy.
To me it means the conductors actually have to be buried. Otherwise, you couldn't treat UF cable like NM when wiring a house and we've all probably seen UF spliced just like romex when used in dry/damp areas.

In the OP's case, I would not call a handhole box a direct buried connection. Its just a (very) wet area junction box.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
To me it means the conductors actually have to be buried. Otherwise, you couldn't treat UF cable like NM when wiring a house and we've all probably seen UF spliced just like romex when used in dry/damp areas.
Iirc, the code has a special allowance for running UF cable like NM in such areas.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Just like buried conduit is considered a wet location, a handhole or JB buried in the ground (even if the top is exposed) is also a wet location. Any splices need to be made using an UG waterproof splice kit since there is always the possibility that the box can fill up with water.

-Hal
 

Ravenvalor

Senior Member
-Hal
[/QUOTE]
Splice has to be made per 110.14 B, IE listed. WP wire nuts are not listed for UF cable, the splicing means must cover the jacket on both cables.

I found the installation instructions for the Ideal Direct Burial Wire Nuts.


It does not mention covering the jacket of the cables. But I believe that it is required for the King Brand of wire nuts.

I wonder if I should not worry about making sure the insulation is covered with the wirenuts but if I want to be extra cautious I can put a coat of Scotchkote on the insulation of the conductors. The conductors in UF cable are listed for wet locations.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Does not look like I have to run the wire nut all the way up to the outer jacket of the cable.

How would that work and what good would it do if you did? You are worried about water being wicked into the cable under the jacket- so am I. Those wire nuts do a good job of protecting the actual splice but what about the cable end and unjacketed conductors? UF is listed for direct burial but that's for the jacket or sheath. If the conductors are marked THWN they should be OK. Are they? Is it OK for water to get wicked inside the cable under the jacket?

-Hal
 
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