First time burying cable - need tips

[humble1]

how many amps total do you want to run?
don't forget about 80/20

 

[cocktail frank]

there are ALOT of factors when trying to do ampacity and wire sizing.
NEC Art 310.16 is ampacity for wires.
that is your base chart, then u have all of your correction factors to consider.

heat is an enemy of electricity.
notice how UF is on the 60 deg C chart?
because of the outer ins. on the jacket, you cant carry as many amps as , persay, thwn.
because of heat.
Correction factors such as temperature, number of conductors, and conductor length influence allowable ampacity.
so if you plan on pulling a 6 6's in that pipe, you can now only use 80% of what the chart for thhn shows (derating)
then u could do a voltage drop calc due to your run being over 100'
w/ all of these corrections (maybe not in your case), your #6 may only be good for a 40A breaker.
just something to ponder.
oh, screw the "free air" chart.
thats only really for triplex sizing.
which is essentially the wire that comes from the pole to your house.
ever notice how the wires coming from the services on people's houses are way larger than the wire coming from the pole?
free air doesnt produce alot of heat.
cuz frankly, its floating in a breeze 24/7

 

[dmt]

if it was me, and i could, i would dig a nice deep trench, bury it with coarse gravel mostly then make a concrete or flagstone path on top of it. anything happens or moves, its your inexperienced handy work and know one will know the better, d

 

[Danks2005]

Why not run a 1/0 in an 1.25" conduit to a 150A panel, then branch out from there. The panels are pretty cheap, see what the difference is in wire cost, and the cost of 3 50A panels vs. 1 150A panel

Pvc conduit is cheap,use 1", 125' wire pull, of 6/3 in a 3/4" pipe will suck. If you don't take the sheathing off the romex you will never get it in. I again would recommend buying THHN #6's or 1/0.

And remember, do not bond your neutral to ground at sub panels, only once at the main.

 

[grow nerd]

I've since read quite a bit on how the ampacity ratings and such were determined, and cocktail frank confirmed everything I (now newly) understand. After reading all that and the confirmations, it seems the "80% rule" was based primarily for typical Romex NM-B installations (i.e., indoor walls in homes and such) due to the 60C rating perhaps coupled along with other non-"100% rated" (90C) equipment, but the bottleneck is at least at the wire.

Turns out the run will be a bit longer than I expected, about 60'. Gonna likely go with #6's and 1" conduit, 3 #6's per.

Would you recommend I get another spool of (smaller gauge, like #10) ground wire or install my own ground rod? I'm leaning towards the former. Solid bare wire, or insulated stranded? Leaning towards latter.

 

[madpenguin]

Grow nerd, your going to kill yourself or someone else in the future.

I'm not really interested in doing things "to code" as long as it's reasonably safe

I hope you realize how ridiculous that statement is... Just what do you think "code" is about then, if not for safety?

You can't run any sheathed cable inside conduit.
You can't strip romex and run that inside conduit.
You cant run THHN in a wet location. That conduit will be full of water. period. No mater what you do.
You can't only bury the conduit 4 inches.

Lots of bad advice given on this thread with only a few people giving good advice.

Why are you running 3 sets of 6/3? Why do you want 3 subpanels? I don't understand.

Please do this the correct way and stop having a complete lack of respect for electricity. I guarantee your going to hurt your self or someone else with that attitude.

https://www.icmag.com/ic/showpost.php?p=2277233&postcount=48

 

[grow nerd]

I seriously doubt it, madpenguin. I understand why codes and standards are in place, whether for electricity or for anything. And as long as I understand the limitations provided by doing things "not to code", I will be fine I guarantee you. I'm not going to go digging around with an auger in the area where I buried my cable. Or really, anything else except maybe shoot some hoops near it.

Why is the conduit going to be full of water? Because you forgot to glue it? I hope you don't say condensation.

The sheathed issue, I now understand.

But thanks for keeping your union work strong, it's a mighty good work you're doing. I'll make sure to hire an electrician when/if I'm ever crippled and in a wheelchair (which you say is likely to happen).

Maybe with the way the industry is moving, some of you people seem to have forgotten what the commercial weed growing game is about. But maybe it's just me!

Funny how you talk down to anyone who doesn't know all NEC codes like they're some retard.

 

[dmt]

if you dont want a known path, then still use the gravel, pour the concrete, then back fill, d

 

[grow nerd]

I think you about nailed it on your first post, dmt.

 

[madpenguin]

I'm not going to go digging around with an auger in the area where I buried my cable

Yes, but what about the person after you? That was my point.

Why is the conduit going to be full of water? Because you forgot to glue it? I hope you don't say condensation.

You obviously have NO experience with conduit. If it's buried underground, it will fill with water. Period. Buried conduit is a wet location therefore you can't use any conductors that aren't rated for wet locations.

But thanks for keeping your union work strong, it's a mighty good work you're doing. I'll make sure to hire an electrician when/if I'm ever crippled and in a wheelchair (which you say is likely to happen).

I'm not in a union. Don't believe in them. You haven't the faintest idea what the fuck you are doing. That much is obvious from your posts. Honestly, these are the types of threads that get closed on electrical forums because you are so blind as to the dangers of electricity and have a complete disregard for protocols set in place to protect people that you will burn something down or kill someone. I guarantee it.

Best of luck to you. Your going to need it.

 

[grow nerd]

You're right, I have no experience with burying cable in conduits... hence the thread title.

How does the water get in? I'm assuming through condensation from air entered through non-airtight boxes, poorly cemented joints, etc., over the course of years? This has a 3-year-max projection.

Think "scope".

 

[grow nerd]

After posting what I've posted (and w/o deleting or editing anything, in respect for madpenguin), it turns out madpenguin is absolutely right about water (quickly!) building up in buried conduits, even glued in properly. This is something that only actual real-world experience would be able to tell you... for the most part...

And the reason is what I feared as the most likely cause... condensation... something I can't easily do to stop unless there are electrically-safe caulk-like or other material that can plug up the ends of conduits to prevent moist air from entering.

Here's a video to sum it up if you don't like reading:

http://www.youtube.com/watch?v=pKEyh_U3Etk

Then info like this:

http://www.southwire.com/support/BuriedConduitChooseJktsThatResistMoisture.htm

Then feedback like this:

http://www.selfhelpforums.com/showthread.php?t=6041

I'm very glad I posted this thread. I was originally going to bury unsheathed Romex NM-B. Very bad mistake! Then THHN. But bare copper (even for ground) is a no-no I've since learned. Now I'm going to have to make sure that my THHN is at least THWN rated as well. I've read that THHN is technically THWN rated but I'll have to double-check unless you can confirm.

Anyways, I gladly stand corrected. Thanks for your input and sharing the experience, madpenguin.

 

[grow nerd]

BTW, running 3 sets of #6 to save on costs based on the length of the run and the amount of wire in a spool or roll, vs. buying wire by the foot. Also, ease of pull and flexibility was taken into consideration. After everything was laid out, I could easily figure out how much power each device is likely to draw at any given point and partition it accordingly... as I've described in an earlier post.

 

[grow nerd]

As a side anecdote, a water-filled pipe buried deep enough in a cold, wet ground w/ lots of groundwater, the wire will be able to dissipate heat more easily than would an air-filled one, wouldn't it? Kinda water-cooled wires.

 

[dmt]

hahaha, i mean if you dont want the exposed concrete path, like you never dug. it can be noticable after rain or an earthquake or false flag terror event or what not, as a raised concern in another post hear, d

 

[Rednick]

code states 4" is deep enough if covered by 2" concrete.

First off the 4" thing is not for power carrying shit, as stated above, unless IT IS COVERED BY CONCRETE. I would probably dig depper, but I don't know code...given all the shit you go through to lay concrete it makes sense to me, though. If you ever seen the electricity that is run through a train car under your feet, you would think 4" under concrete is sufficient. Other wise 4" is for your cable, or telephone...that way an aerator doesn't bust them.

Also, people are just wondering with power carrying considerations why you want THREE subpanels or circuits, versus doing a proper job on a proper subpanel on your guest HOUSE. Then wire amperage down from there.
It would mean only one trench be dug, straight shot.

Just know, that even if people come off as pissed off. It is just because we don't want you to; electrocute yourself, burn a familly alive (you may be long gone), or hell, even just be another grower burning down a house.

Most of all, we don't want to hear about you losing your crop to fire.

 

[madpenguin]

Go back and read the thread I linked to if you haven't already. It lists Table 300.5 along with general info about wiring detached structures.

You can't use this romex at all. Not in conduit while sheathed, not in conduit without the sheath and not direct buried.

NEC Article 310.8(C)(2) (uh oh.. Heres some code you dont care about)

Cable types MTW, RHW, RHW-2, TW, THW, THW-2, THHW, THWN, THWN-2, XHHW, XHHW-2, ZW

I don't see THHN in there, do you? For all of you giving electrical advice, QUIT DOING IT unless you know what your talking about. You can't strip romex. Again, we have an electrical engineer saying that you can along with other people. JUST STOP!

This shit really gets under my skin. You people are going to kill someone someday. THHN/romex, when wet, likes to literally EXPLODE.

Also, you should use pea gravel above and below your conduit for contraction and expansion reasons. Your pipe will crack/pull apart if you just bury it with soil.

 

[Danks2005]

Have you compared the cost of 9 #6's to 1 1/0, or 3 50a sub panel vs. 1 150a panel. You can balance the load from 1 panel you don't need 3.

3 years is not so temporary, plenty of time for things to go wrong, do it right or hire someone to do it for you. Temporary would be a flowering cycle or two, and in that case I would use some SO cord, a twistlock, and not bury it.

 

[madpenguin]

Yea, that was another issue that makes no sense to me that I touched on earlier... 3 panels with 3 feeders? Wow. What a waste of money.

I'd look at Table 300.5 to see how deep to go and direct burry XHHW. At either structure, use a conduit sleeve for it to enter/exit the buildings. Look at table 310.16 for both hots and the neutral gauge wire and look at table 250.66 for what size ground wire to run. Run it all in one conduit using Annex C for conduit size and fill (or just direct bury the conductors) and use a main breaker panel in the detached structure to serve as your disconnecting means. Drive a rod and bond it to the isolated ground bar in the panel. Your done.

 

[grow nerd]

Isn't THHN (and THN) rated for wet conditions, due to the "N"? I.e., THN = 75C + nylon, THHN = 90C + nylon. No?