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View Full Version : #4 THHN/THWN In Conduit Above Ground


rr6
Sep 9, 2013, 04:52 AM
I believe understand-- to whatever degree ---how over the years, something unsuspected happens, that is potentially dangerous or actually hurt someone or property, with electrical, that causes the existence of codes and the changing of the codes over the years.

I'm trying to avoid digging 18 to 24" trench through numerous large tree roots and under and old house, that has no room to crawl under.

That said, I'm not aware of any codes that would allow me to run 2, #6 THHN/THWN and #8 neutral and ground, in 1 -1/4 sch.80 PVC conduit laying on ground through the woods to my personal cabin.

There is a walkway to my shed/shop and if ever needed to drive pickup truck of firewood over conduit, I could build strong 4x4 etc.ramp to drive over conduit.

I'm even considering putting the conduit inside of a larger 2" or 2 1/2" PVC pipe for extra protection. Is anyone aware of any situations or codes the wood apply to my given plan above?

Thx, r6

ma0641
Sep 9, 2013, 05:51 AM
Why not run elevated outdoor approved cable supported by a messenger cable. How far are you talking?

rr6
Sep 9, 2013, 03:28 PM
Why not run elevated outdoor approved cable supported by a messenger cable. How far are you talking?

Hi and thanks for reply. Before going further, do you know what is the minimal size conduit is for 2, #6's, and 2, #8's in sch 80?

I will go to the next size or larger, and out in the woods I really would like to put all inside a 2nd run of pipe that is not glued, but I first need to know what the first pipe size will be. I think 1-1/4 would pull no problem and that inside 2" pipe is my guess at this time.


I'm going maybe a80 - 90 ft long diagonal under a little, to no crawl space, under my old house with the main panel on far away corner,

then 110 - 120 ft through big oark trees to the cabin.
If any large branches or trees fall, there is likely to be damaged to the sch 80 THHN/THWN inside, if I dont have 2nd outer conduit. And sure, if a big enough branch or tree falls on both yeah still probably going to be damgaged wire.


Still trying to mimimize with least amount of costs. I can always repair with a junction box out in woods, tho not sure yet how I would go about that.

I'm not sure what your "elevated" entails but probably more expense and will not avoid tree branch or trees falling on it.

Yeah I suppose a very good and well fixed support cable would help as I had a friend drop to large branches and they hit the 2ndary feeds to my meter on old house but the support cable did tear out from the season oak end rafter that it s lagged bolted into.

Since the THWN is for wet locations I would love it if I did not have to glue all the joints but I know if those wire ever get exposed, there much more susecptable to damage from any raccoons, squirrels etc... or tree branches etc..

I'm thinking 6/3 out of main panel into a junction box under the floor. Then I could put wire into conduit piece by piece with rope to pull line through after glue drys.

Then when I get a long enough run of pipe I can shove in the 80 -90 fit long diagonal under house. As long as I don't use PVC rope, as it will get glued to PVC conduit, I think I can do the piece, two or three at a time.
r6

ma0641
Sep 9, 2013, 03:40 PM
On your own, with no code enforcement, do whatever YOU want. Just remember it is 240 volts laying on the ground. However, it is against the NEC to just lay the conduit on the ground. Burial is 18" for Non Metallic Conduit.

rr6
Sep 10, 2013, 04:25 AM
On your own, with no code enforcement, do whatever YOU want. Just remember it is 240 volts laying on the ground. However, it is against the NEC to just lay the conduit on the ground. Burial is 18" for Non Metallic Conduit.

Yeah 240 volts is not your ordinary extension cord laying on floor or yard for temporary work period nor through rain snow night after night, day after day.

Others have stated some articles about the conduit not being susceptable to damage. My conduit would not be fixed for no lateral movement either.

Thx. Yeah burial through all those large roots is best.

r6

hfcarson
Sep 10, 2013, 06:55 AM
Ah... there's no excuse for hard work...

rr6
Sep 10, 2013, 02:47 PM
ah...there's no excuse for hard work....

Yeah I've done my share of hard work including diggingby primary line 3' trenches and 2ndaryline 2' trenches and chain sawing huge root systems etc...

I realized though, that by running diagonal under house in conduit, I come out past the larger closet trees to where the trench would be, so, with that in mind,

I feel better about doing the trenchthat last 100 ft or so, though it is still another $109. Plus my time getting and returning it and filling in the hole and there will still be plenty of annoying medium and smaller roots as I'm in a moderate forest here.

I found good chart for number of conductors in conduit so probably go with 1-1/4"
for those 2-#6's and 2-#8's since it is pretty much a straight pull. 1-1/4 would also fit inside 2"-- I think? --- if I were to decide to try the above ground method.

I also thought of buidlingtreated wood support over the pipe as extra protection but then were approaching and going over the cost of trencher and bury labor.

r6