Another wiring question

[Doc]

I'm planning my wiring job for adding electric to my pole building. My most direct path would go under my parking area where I'll be laying concrete soon. I can go around this area, but it will put multiple bends in my run, harder to pull a wire through if needbe. Is running wire like this under concrete a good idea?

 

[OhioTC18]

I'm planning my wiring job for adding electric to my pole building. My most direct path would go under my parking area where I'll be laying concrete soon. I can go around this area, but it will put multiple bends in my run, harder to pull a wire through if needbe. Is running wire like this under concrete a good idea?

Doc, Under any type of pavement I would use a sleeve of PVC, but that's just my opinion.
IF for any reason you needed to replace it, the pipe sleeve will be there.
Just make sure it's at least 24" down and you'll be code compliant.

 

[bczoom]

Jerry,

Does it need to be PVC? I ran 4" S&D pipe and have had no problems.

Doc,

I ran 4" with my ele, phone, internet, coax... and all is working well. No interference.
I also left a couple strands of ele. fence wire in the conduit so I have something in there in the event I want/need to pull something else.

 

[OhioTC18]

Brian,
PVC is what I'd approve

 

[Av8r3400]

Put down as large of a conduit as you can and make sure to put a few "dead runs" through it in case you want to pull something else through in the future. (telephone, cable TV, satellite feed, alien antenna hookup, etc.)

 

[bczoom]

Brian,
PVC is what I'd approve

Thanks. I'll do that in the future.
It was almost 10 years ago when I used S&D but it still works

 

[Doc]

Inspector, any certain type of PVC? I was thinking of the 3 inch white pipe, but 4: might be better. But it has a thinner wall. Does that matter?

BC, what is S&D?

 

[Spiffy1]

I think he means Sewer and Drain pipe. Out of my realm of knowledge, but I think it is a form of PVC, perhaps a lighter wall thickness or something.

 

[HGM]

Good idea! I dont thing it matters what you use, though the guys that do it on a regular basis would have the code in mind.. But I like the larger pipe better, more possibilities.. Once its there you shouldnt have any forces acting on it to brake it or move it, so the thin walls should be fine(IMO).. I was originaly thinking conduit, but thanks for the ideas...

 

[Cowboyjg]

Typically the grey utility conduit is used and suggested. Thicker wall and will not break as easily as the standard white should you or someone else end up digging where the pipe is for some unforseen reason. You can use the large white as the sleeve if you like.

 

[bczoom]

Yes. S&D = Sewer and Drain.

It is PVC pipe but has much thinner walls than schedule 40 or something. I used it since it is A LOT cheaper than schedule 40 pipe.

I mis-interpreted OhioTC18's earlier post and was mentally thinking SCH-40 in his replies but now wonder if he was saying the pipe I used is OK since it is PVC.

Here's a PDF with some info on the S&D pipe.
http://www.flyingwplastics.com/pdf/SewerCatalogFWP.PDF

 

[OhioTC18]

I guess I didn't say what type of PVC

If you used the white PVC in my area, you're gonna have a whole lot of plumbing pipe to do something with. You might be able to run your air line out to the barn with it

The gray is what is listed and labeled for electric use. Boy, I seem to be stuck on that listed and labeled crap huh? The gray commonly comes in two thickness'. Schedule 40 and schedule 80. The 80 is for use where subject to physical damage, such as out by the road running up the pole.

I know some of you live in areas that don't use codes/inspections or use a version that is 10 years behind. And you're going to use what you want, no matter what I say. But that's okay. When I try to answer a question I base my answer on what is called for in my area. I appreciate the way I have been allowed to answer questions here without getting trashed. If anyone is a member of some of the other forums that I am, probably have noticed I don't answer things over there. One of these days I'll see the glow down on the horizon.....

 

[Doc]

I don't have to have the work inspected but I prefer to do it right. Thanks for setting me straight Jerry!

 

[Doc]

I'm confused again.
I went wire shopping. The Lowes guy said 2-2-2-4 would be good for up to 100 amp service running 150'. This is aluminum. If buried over 18" no conduit needed. If none was needed I'd use the 4" sewer pipe anyway, so I could pull additional wires if needed. If I prefered to go copper it would cost me to much to do the job. Copper has just gone up again.

I know rules vary by location but this is so far from what I was expecting, I'd like to here from the experts. What is the disadvantage of aluminum?

 

[Dutch-NJ]

Doc:

I'm NOT an electrician, but watch out using that thin wall PVC.

I buried thin wall for my gutter drains, and the weight of the fill (dirt) collapsed it. Had to dig it up and replace with sched. 40.

None of the PVC is really THAT expensive. My suggestion is........... Do it right the FIRST time.

PS - No matter what you use, lay some Yellow plastic "Caution" tape in the trench after the first 12" of backfill as a warning and guide for the next backhoe operator.

I even bury a length of 16-12ga. "dead" wire in the trench to use for a "tone" if I ever have to find what is buried (just leave the ends exposed and marked "tone" near the ends of the cable).

 

[johnday]

Doc; Jerry can whack me if needed, but the disadvantage of using aluminum is that you are mating up two dissimilar metals. The aluminum expands and contracts much quicker than copper. When you join the two, coat the aluminum with an anti-oxidant like No-Alox [sp]. This tend to minimize the connection working loose over time. After, say six months, if you use the Al, retighten your lugs on the connection. Be very CAREFUL! Those lugs can be hot unless you kill your main disconnect [breaker], or sometimes even have to pull your meter. No real big deal to do this, just a little time, and KEEP SAFETY IN MIND!!!!

 

[Doc]

I even bury a length of 16-12ga. "dead" wire in the trench to use for a "tone" if I ever have to find what is buried (just leave the ends exposed and marked "tone" near the ends of the cable).

Dutch, the caution tape is a very good idea. I'm not familiar with the 'tone'. If you have caution tape in place what is the purpose of a 'tone'?

John, were the lugs needing tightend the saftey issue with aluminum? I vaugley remember a fire issue with aluminum.

Do any of you use aluminum on your projects?

 

[Jim_S]

Dutch, the caution tape is a very good idea. I'm not familiar with the 'tone'. If you have caution tape in place what is the purpose of a 'tone'?

makes it easy to find the location of the cable using a tone generator and tracer. Tone equipment designed for telephone or cable service can't handle being connected to live conductors.

John, were the lugs needing tightend the saftey issue with aluminum? I vaugley remember a fire issue with aluminum.

Do any of you use aluminum on your projects?

The fire problems were with aluminum used in wiring to outlets, switches, etc. Aluminum is used all the time for feeders with no problems. Thing is to properly install it using the correct connectors and check it after installation. I added a sub panel in my basement last year with aluminum.

Jim

 

[bczoom]

I'm pretty sure mine are aluminum.

Doc - Yes. The caution tape is a good idea but to do it right, I believe it's supposed to be red tape to denote buried electric.
Here's an example.

 

[johnday]

Doc; Jim's right on with his reply. I've used both copper and aluminum for new services and updating old ones, including adding subpanels. The Al is cheaper than copper, but a little harder to work with. For a service or subpanel, you have to go one wire size larger with Al than copper. I do beleive that has to do with the Al expansion/contraction issue, that overtime can loosen up the connections. I prefer copper, you can twist it up pretty tight, since it's not as brittle as Al.
As of this time, I believe also that Al is not approved for branch circuit use. I don't think your subpanel would fall under that restriction, so, I guess for your use, it would depend on how much you would save with Al, opposed to the little extra work you'd have to do. I've no problems running Al, but like I said, I prefer copper.

 

[OhioTC18]

I'm confused again.
I went wire shopping. The Lowes guy said 2-2-2-4 would be good for up to 100 amp service running 150'. This is aluminum. If buried over 18" no conduit needed. If none was needed I'd use the 4" sewer pipe anyway, so I could pull additional wires if needed. If I prefered to go copper it would cost me to much to do the job. Copper has just gone up again.

I know rules vary by location but this is so far from what I was expecting, I'd like to here from the experts. What is the disadvantage of aluminum?

Doc,
For a 150' run, yes you can use #2 AL. You're going to see approximately a 2.4% voltage drop. Nothing unreasonable. The wires being buried without conduit will be determined by insulation type. Let me know what that is and we can say whether conduit is needed or not. But most direct buried cables need burried 24".
As someone else mentioned the expansion and the oxidation of aluminum can be an issue at your terminations. If you're running the wire from one panelboard to another without splices, you'll be better off. However if splices are needed, use a split bolt or"kearny" rated for CU/AL. It will have a separator bar in to keep the CU from touching the AL. Use an antioxidant compund. This won't make your conductor not expand, but it will reduce the oxidation on the conductor which increases resistance and contributes to heat and a poor joint. Most of the bad issues with Aluminum are with smaller sizes of wire, but any poorly installed Aluminum wire can cause problems.
Caution tape and a tracer wire are always a good idea, but it contributes somewhat to the final cost.

 

[bczoom]

But most direct buried cables need burried 24".

By code, aren't they supposed to be surrounded for a few inches in all directions by sand as well?

 

[OhioTC18]

By code, aren't they supposed to be surrounded for a few inches in all directions by sand as well?

Not according to the NEC. Which BTW, that is what we use here and that's what I base my answers on. So if you live in a locale that uses something different or nothing at all, your mileage will vary.

 

[Dutch-NJ]

Dutch, the caution tape is a very good idea. I'm not familiar with the 'tone'. If you have caution tape in place what is the purpose of a 'tone'?

Jim Slagle answered your question regarding the tone wire. It saves from digging up where you “think” the cable was buried 20 years from now.

Bczoom is correct, do it right, use the red tape. I only use yellow because that’s what I have for free. If you dig up my yard, you’ll find “Police line... Do not cross.”

 

[mtntopper]

If you dig up my yard, you’ll find “Police line... Do not cross.”

Hmm wonder whats deeper? Do you have other buried secrets below the yellow marker. Can you imagine the curiosity 50 years from now when the new owner digs up your yellow marker???? Anyone missing any relatives in that area????

 

[beds]

Anyone missing any relatives in that area????

Ummm, it's New Jersey...

 

[Dutch-NJ]

Ummm, it's New Jersey...

What's that supposed to mean? Huh?

This is the Garden State not the Graveyard State.

Is it our fault out-of-town hooligans bury corpses here?

Besides, I'm convinced many of the buried bodies are suicides. Just last week they dug up body with 14 stab wounds in the back. But there was a suicide note pinned to the chest.

 

[kensfarm]

Doc.. I'm glad you are asking these questions.. I need to do the same thing to my barn.. currently the barn only has a 20amp line running out to the barn.

 

[Doc]

Good Ken. Hope it helps.

I was shocked at the cost of the gray pvc conduit. Why is it so much more expensive. I hadn't thought of the pipe caving in like dutch mentioned. The 3" pvc has a thicker wall. About the same thickness as the gray electrical rated conduit. Can someone tell me the difference in the two.
If conduit is not required below 18", I still want to put it in pipe, but see no good reason to pay over $500 for the gray stuff. Maybe you guys can set me straight. Is there a valid reason to pay out the big bucks?

I need to save a few bucks so I can buy a tiller from Wannafish .....Junk will never close the deal.

 

[bczoom]

I would like to know more about teh conditions of the collapse for Dutch.

I have over 1000' of the S&D pipe running under my yard and to my knowledge have no collapse. After all, that's what that pipe is made for...