"In-ground" junction box, residential 120v

[UBG]

I have a customer who wants to get rid of her existing above-ground "bell box" splices for aesthetic reasons. (The existing UG conduit is RMC). I know I have run into, or used at some early point in my career, some type of box (brass, i think?) that was buried in the ground and contained spices. I THINK the cover was "exposed" at the surface of the soil, but don't actually remember it very well. A version of this approach used to be used for swimming pool lights all the time in these parts, but is now not allowed....besides, those "deck boxes" were in concrete, not in soil.

I have scoured the forums here, and found lots of relevant info (handholes, etc.) but nothing that quite explains how this needs to be done, if it's even do-able, legally speaking.

I have found that Carlon now makes a PVC box that has a NEMA 6P rating, but it does not apear to have threaded hubs (not that those are water-tight, anyway). If something like that would do the job, how would the conduit entrances be handled and sealed?

Another idea I got from searching here was to use a condulet or box, inside a handhole. I'm in Los Angeles, and we do get some heavy rains some years...i can envision a handhole, even if installed with some gravel for drainage at its base, filling with water occasionally.

Any and all advice is much appreciated....Thanks.

 

[cadpoint]

Your going to move some earth due to it being RMC, with your answer one could:

Get both POCO, and AHJ involved.

With POCO you could pull through and eliminate the boxes.

With the AHJ, the desired answer/blessing... You get to ask them both too...

 

[jumper]

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.

 

[tkb]

I have a customer who wants to get rid of her existing above-ground "bell box" splices for aesthetic reasons. (The existing UG conduit is RMC). I know I have run into, or used at some early point in my career, some type of box (brass, i think?) that was buried in the ground and contained spices. I THINK the cover was "exposed" at the surface of the soil, but don't actually remember it very well. A version of this approach used to be used for swimming pool lights all the time in these parts, but is now not allowed....besides, those "deck boxes" were in concrete, not in soil.

I have scoured the forums here, and found lots of relevant info (handholes, etc.) but nothing that quite explains how this needs to be done, if it's even do-able, legally speaking.

I have found that Carlon now makes a PVC box that has a NEMA 6P rating, but it does not apear to have threaded hubs (not that those are water-tight, anyway). If something like that would do the job, how would the conduit entrances be handled and sealed?

Another idea I got from searching here was to use a condulet or box, inside a handhole. I'm in Los Angeles, and we do get some heavy rains some years...i can envision a handhole, even if installed with some gravel for drainage at its base, filling with water occasionally.

Any and all advice is much appreciated....Thanks.

Do these boxes have anything to do with a pool or are they near a pool?

 

[kwired]

Your going to move some earth due to it being RMC, with your answer one could:

Get both POCO, and AHJ involved.

With POCO you could pull through and eliminate the boxes.

With the AHJ, the desired answer/blessing... You get to ask them both too...

Why POCO? From what he described it doesn't sound like it involves service conductors so why will they even care?


What was the reason for the boxes? If they were needed as pull boxes because of number of bends in the raceway you likely still need a acess point. If it is just elimination of an outlet that is no longer needed or something of that nature How about pulling conductors, remove above ground portion make raceway continuous and pull new conductors. This will likely cost less than underground enclosures. You will have moisture entering almost anything you place in the ground so if there are splices you will want to splice with a method that seals the splice.

 

[UBG]

Do these boxes have anything to do with a pool or are they near a pool?

Thanks Tim...no, they are not near, or having anything to do with a pool...they are (were) for landscape lighting (120v) and power.

 

[UBG]

Why POCO? From what he described it doesn't sound like it involves service conductors so why will they even care?


What was the reason for the boxes? If they were needed as pull boxes because of number of bends in the raceway you likely still need a acess point. If it is just elimination of an outlet that is no longer needed or something of that nature How about pulling conductors, remove above ground portion make raceway continuous and pull new conductors. This will likely cost less than underground enclosures. You will have moisture entering almost anything you place in the ground so if there are splices you will want to splice with a method that seals the splice.

Thanks kwired, you're right, no service conductors involved, just branch circuits. Most locations have just two conduits, and can be made continuous and re-pulled. In two locations, however, there are 3-4 conduits in each of those boxes, which feed lights that need to be kept and can't be re-fed in any other practical way (post-lanterns, mounted on top of masonry pilasters). I'll definitely be using some version of a "sealing" wire nut to make the splices...

 

[renosteinke]

I suppose we need to return to this topic from time to time, simply because the 'correct' method is so different from the way we 'usually' do things as to be difficult to imagine.

First off, forget everything you've ever learned about boxes and splices- and I do mean EVERYTHING. Here's how you run wires in the ground:

To begin with, forget the finer points of the burial tables. For reasons completely unrelated to the NEC, you want to run the wires 18-24" beneath the surface, no matter the wiring method. There are two reasons for this:
First off, you want the wires beyond casual shovel reach, and under the sprinklers and whatnot that are more likely to need servicing.
Second, the best way to enter a handhole is from beneath- and handholes start at about 16" deep/tall.

A 'handhole' is simply a tube with a cover on top. Round or rectangular, fiberglass or concrete, it's wide open on the bottom. It also has a taper or flange to help keep it from popping up out of the ground. The most basic version is about the size of a 5-gal. bucket. These are similar to the things gardeners use to access lawn sprinkler valves, but a bit larger.

A bit of gravel or sand in the bottom of the hole will help you to level and secure the handhole in place. The open bottom let water drain out as easily as it comes in. Your wires, or conduit, enter the handhole and end there; they are not attached to the handhole in any way. I try to set the top in line with the contours of the ground, and just slightly below the surface. Say, about 1/2" below the bottom edge of a level spanning the hole. This is to prevent tripping, and impacts with lawnmowers.

I say it's best to enter the handhole from below because this results in the wires pointing 'up' (much easier to work with), and if you're pulling wire through pipe you can pull much better.

Your 'waterproofing' comes from your splicing method. There are a number of methods that do not involve the expensive grease-filled wire nuts. Personally, I usually just dip the connection -ordinary wire nut and all- into a jar of Scotch-Kote. For exceptionally wet locations (like sump pits), I insert the connection into a Scotch epoxy-pack and let it set up.

Wire length is important. You want 'free wire' that is somewhere between 24" and 36" long. This will let you bring the connections up out of the ground to work on, and will also let you coil the wire so that the wire nuts are 'pointing up,' or to drain.

 

[iwire]

Here's how you run wires in the ground:

No, that is how you run wires in the ground, I doubt you know how I do it.

 

[steve66]

I don't know why you couldn't use a Quazite box, although they may be a little large.

http://www.hubbellpowersystems.com/about/quazite/

It will fill up with water at some point (even the gasketed ones), so waterproof splices are required.

 

[renosteinke]

I can imagine the dialogue:

Reno: OK, Iwire, how do you run wires in the ground?

Iwire: I pour a cup of coffee, take a deep breath, and bellow: Apprentice! Front and center!

 

[iwire]

I can imagine the dialogue:

Reno: OK, Iwire, how do you run wires in the ground?

Iwire: I pour a cup of coffee, take a deep breath, and bellow: Apprentice! Front and center!

:lol::lol:

Boy you nailed that .......

 

[tom baker]

Your 'waterproofing' comes from your splicing method. There are a number of methods that do not involve the expensive grease-filled wire nuts. Personally, I usually just dip the connection -ordinary wire nut and all- into a jar of Scotch-Kote. For exceptionally wet locations (like sump pits), I insert the connection into a Scotch epoxy-pack and let it set up.

QUOTE]

What section of the NEC allows dipped wire nuts?

 

[renosteinke]

The same section that allows electrical tape....

Really, now ... you're using a listed product (Scotch-Kote) in accordance with it's labelling, and you want a 'mother may I' clause in the NEC?

OK, be exacting ... twist the wires, then dip them. There's no requirement to use the wire nuts at all- only that the connection be mechanically and electrically secure.

 

[cadpoint]

I don't have a problem with my answer verses the information as presented.

 

[kwired]

Your 'waterproofing' comes from your splicing method. There are a number of methods that do not involve the expensive grease-filled wire nuts. Personally, I usually just dip the connection -ordinary wire nut and all- into a jar of Scotch-Kote. For exceptionally wet locations (like sump pits), I insert the connection into a Scotch epoxy-pack and let it set up.

QUOTE]

What section of the NEC allows dipped wire nuts?

I will counter that with:

What section of the NEC disallows dipped wire nuts?

 

[UBG]

I suppose we need to return to this topic from time to time, simply because the 'correct' method is so different from the way we 'usually' do things as to be difficult to imagine.

Thanks, reinstoke, lots of practical advice here...

To begin with, forget the finer points of the burial tables. For reasons completely unrelated to the NEC, you want to run the wires 18-24" beneath the surface, no matter the wiring method. There are two reasons for this:
First off, you want the wires beyond casual shovel reach, and under the sprinklers and whatnot that are more likely to need servicing.

My client would love that, she's an avid gardener, constantly digging around, BUT...as I mentioned in my OP, this situation is an existing installation. The existing RMC is buried with only 6-8" of cover at the locations I have to modify. Can't tell whether this is due to erosion (the garden is sloped at these points) or if it was installed shallow to begin with...probably both.

A 'handhole' is simply a tube with a cover on top. Round or rectangular, fiberglass or concrete, it's wide open on the bottom. It also has a taper or flange to help keep it from popping up out of the ground. The most basic version is about the size of a 5-gal. bucket. These are similar to the things gardeners use to access lawn sprinkler valves, but a bit larger.

A bit of gravel or sand in the bottom of the hole will help you to level and secure the handhole in place. The open bottom let water drain out as easily as it comes in.

Nice detail, I appreciate that....using a handhole is new to me.

Your wires, or conduit, enter the handhole and end there; they are not attached to the handhole in any way.

THIS is key to my situation, and a new way for me to think about this...I have been locked in to thinking that any kind of conduit has to attach to a junction box in order to create an approved "space", for lack of a better word, to splice in...you're saying, for an underground handhole, this is not true?

I say it's best to enter the handhole from below because this results in the wires pointing 'up' (much easier to work with), and if you're pulling wire through pipe you can pull much better.

Can't do it this way in my situation (due the the depth of the existing conduits), but I'm envisioning cutting slots in the walls of the handhole, from the bottom up to whatever height I need in order to clear the conduits, and the conduits then poke into the sides (handhole slides down over the existing conduits, and they fit into the slots that I will have cut at the needed points in the side-walls of the handhole).

Your 'waterproofing' comes from your splicing method. There are a number of methods that do not involve the expensive grease-filled wire nuts. Personally, I usually just dip the connection -ordinary wire nut and all- into a jar of Scotch-Kote. For exceptionally wet locations (like sump pits), I insert the connection into a Scotch epoxy-pack and let it set up.

I'll have a total of 8 splices, heheh, so I'll do the math on expensive WP wire nut vs. jar of Scotch-Kote

Wire length is important. You want 'free wire' that is somewhere between 24" and 36" long. This will let you bring the connections up out of the ground to work on, and will also let you coil the wire so that the wire nuts are 'pointing up,' or to drain.

Again, very practical, I like the way you think. I'm amazed at how often I find wire nuts pointing DOWN in an outdoor Bell-box, full of rust and/or water. I'm also amazed at how I NEVER see the required drainage holes drilled in these outdoor boxes. I drill them all the time, but in 25 years in this trade I have only seen ONE other electrician do it that way. I know that's in the Code somewhere; if any of you guys could point me to the section, I'd appreciate it (yes, I'm just lazy :ashamed1: )

 

[UBG]

Any new thoughts?

Any new thoughts?

Thanks again to all the responders....I'm just wondering if anyone else had a thought on this.

 

[Sierrasparky]

Thanks, reinstoke, lots of practical advice here...





I'm also amazed at how I NEVER see the required drainage holes drilled in these outdoor boxes. I drill them all the time, but in 25 years in this trade I have only seen ONE other electrician do it that way. I know that's in the Code somewhere; if any of you guys could point me to the section, I'd appreciate it (yes, I'm just lazy :ashamed1: )

I do , I DO ..................................when I don't forget

 

[renosteinke]

You understand my description quite well ....

Let's use a concrete "Quartzite" box just for discussion, for a moment. The situation is that a pipe, or UF cable, enters from the side. What usually happens is that a guy will take a hammer and knock a hole in the side; the sides have 'thin' spots to make this easier. The pipe or cable will then pass through the hole. There is no direct connection, no connector, between the handhole and the pipe or cable. You're right- it goes against everything you've ever done before.

As a side note, I think it also makes it easier to understand how we sometimes hear of the metal covers becomming energized. I think the new metal covers have provisions for attaching a bond / ground wire.

Existing location, with pipes coming in the sides? No problem. Just be sure that the weight of the box does not rest atop the pipe or cable. Think of the edge of that box acting like the dullest pair of scissors you've ever seen; eventually it will cut into the wires.

Another 'detail' often overlooked is that pipes / cables / boxes ... anything in the ground ... move with time. I've seen buried conduit surface, after being pushed up by growing tree roots. I've seen straight runs wiggle all over the place with time. Some things sink, others float, and the frost heaves everything around. Another reason to 'run deep' when you can.

Your handhole can be buried under bark, mulch, etc. That is allowed. As a personal 'rule of thumb,' I want it above the weed cloth, and I want to be able to find it with a garden rake- not a shovel or ground rod!