Extending underground conduit.....


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Old 04-30-08, 08:19 AM
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Extending underground conduit.....

I currently have power running in PVC conduit to my pool filter. I want to relocate the filter power/timer to a different area which would involve extending the conduit and power wire.

Is there any approved method for doing this *underground*? i.e. can I use an LB type pull box and bury it?

Or do I need to come above ground, add the box then run the extra wire back underground to the final location?

The setup is all 4 THWN conductors thru 3/4" sched 40 conduit.

Thanks in advance.

-Chris
 
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Old 04-30-08, 08:36 AM
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Originally Posted by chrisexv6
Is there any approved method for doing this *underground*? i.e. can I use an LB type pull box and bury it?
Nope.

Or do I need to come above ground, add the box then run the extra wire back underground to the final location?
This is what you have to do. You can come up above the ground and use a "bell box", or you can get a flush box that buries level with the surface of the ground. This type is usually available in a green fiberglass to blend in with the lawn.

The extension needs to also be THWN in conduit to match the current supply.
 
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Old 04-30-08, 08:37 AM
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No you cannot install an LB and bury it.

Why not just cut the conduit off and re-route it to the new location? This way you would not need to worry about a handhole box in your lawn.
 
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Old 04-30-08, 09:40 AM
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Originally Posted by pcboss
No you cannot install an LB and bury it.

Why not just cut the conduit off and re-route it to the new location? This way you would not need to worry about a handhole box in your lawn.
I can cut the conduit but I dont think there is enough wire inside of it to get to the new location, so I will need to add some wire. Basically its at the end of the run that I need to move to a new location, it might be short by not much at all, but short is short and would need to be fixed. It might be long enough, I didnt want to cut it until I knew this whole thing is even possible.

Ill look into a box that flushes with the lawn, or if the current wire can make it to a hidden area to install an above ground junction out of sight.

-Chris
 
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Old 04-30-08, 09:44 AM
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How long is the total run? It might not be too bad to just replace all the wiring.
 
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Old 04-30-08, 10:03 AM
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Originally Posted by ibpooks
How long is the total run? It might not be too bad to just replace all the wiring.
Not about to happen at least 150'. I replaced it myself last year when the patio installer hit the old wire with their Bobcat (not their fault, the wire wasnt buried deep enough because of a previous splice that I hadnt known about)

I should have just ran the electrical to where I want now, but I was in "get it up and running ASAP" mode.....90 degrees and sunny with no pool filter running = green pool.
 
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Old 04-30-08, 06:44 PM
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I have one question how many #4's you have in the 3/4 conduit ?? IMO it sound way too tight for that size and if it was THHN/THWN it might be ok i say " just might " until i know little more with the type of insluating materals on the conductor generally it will be printed on them so you able see what it say there.

Merci,Marc
 
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Old 05-01-08, 06:52 AM
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I have 4 12AWG THWN stranded conductors in the 3/4" conduit. (I reread my original post and saw that I wasnt clear on the size of the conductors ).

From what I understand that leaves plenty of room...Im never adding to it, but didnt want to do leave only the bare minimum amount of space either.

Oddly enough a stroke of luck.....there was enough wire to cut the existing conduit back and run to an out-of-sight area to put an above ground junction box, then run on to the final location. Usually I dont get lucky like that but this time I did.

-Chris
 

Last edited by chrisexv6; 05-01-08 at 07:09 AM.
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Old 05-01-08, 06:28 PM
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Is there any reason why he can't just use a small hanhole and water proof splices to extend this circuitry?
 
 

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