I want to run a pipe to my detached garage that I can pull either phone and or tv cable through at a future date. I was going to use 3/4″ pvc, but I can’t seem to find “sweeping” (aproximate shape of conduit bent into a 90) elbows in this size. Only 1 1/2″ or larger. I have to make a few 90 degree turns and I don’t think i will be able to pull through regular pvc elbows. Are these available somewhere or should I be using a different approach to underground pipe.
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Replies
I'm doing the same thing...possibly later this summer.
I was thinking about black plastic pipe, same stuff used in underground sprinkling systems. I'm thinking I could avoid elbow fittings and bend the pipe around as needed.
Any thoughts anybody??
You don't use "pvc pipe" use pvc conduit.
The main difference between the 2 are that a) is gray instead of white b) it is the electrical isle instead of plumbing, c) it has the right fitting available.
That said the OP has a good idea. Use PE pipe. There is even approved versions of this used all the time.
http://www.wesflex.com/prod01.htm
But for your purpose the common black PE will work.
"I have to make a few 90 degree turns "
BAD idea. Minimize turns if at all possible. For your needs (fellow DIYer to DIYer) use the biggest conduit you can. and if you glue up a long run of it, it will bend nicely on a radius so long as you don't ask it to bend too sharply. This may help you avoid some 90's. Code prohibits bends totaling in excess of 360 degrees between pull locations. And trust me, get a few 90's in there and you'll understand why. The wire is a real pistol to pull with too many bends in it.
Agree to use PVC conduit. In the electrical aisle, use sweep 90s and 45s where needed. The white PVC is too brittle (or will be after exposed to suinlight for awhile) And use the special conduit glue, it seems to work better for me than the glue for PVC plumbing. (The PVC glue is gray and can be found with the conduit)
Went to a couple of big box stores looking for pvc conduit. They looked a t me like I was nuts. I'm going to try the electric supply house after the holiday to try there.
You did not go down the electrical isles right next to the area that has ENT and similar products.Can't believe that they don't have it.
The "boxes" must not have been very "big" if they didn't have nonmetallic conduit. or maybe just incompetent employees.
Just look around for the grey pipes in the electrical section. The ones 10 feet long, with the UL stamps on them.
No, my HD definetly doesn't have any pvc conduit in the electrical department. And almost as nonexistent is someone qualified to know what on earth I was talking about. I ended up going to a huge elctric supply house and they had it all. Settled on 1 1/2" conduit. They told me to use regular pvc cement, but I believe a poster here said to use some special glue? And do I prime it like white pvc?
I really appreciate all the helpful advice on this project. I decided to remove the existing 120v feed to the garage. It was a direct burial cable that was tucked between the grass and a sidewalk, about 2" down. I'm surprised I didn't get it with the edger. Then to go across the sidewalk into the garage, they chisled out a little v in the concrete, put the cable there and patched over it. This is going to be a big improvement.
Edited 6/4/2005 9:49 am ET by rich
bump
I'm baffled that your local HD doesn't have grey electrical PVC conduit. But I notice you are in Chicago, which has unusual electrical codes because of that cow a long time ago. Even if EMT is required inside, you would think they would stock it for underground burial purposes.
PVC primer and PVC cement work on both plumbing PVC and electrical PVC. Definitely use the primer. (If you're gluing a part that will show, use the clear primer instead of the purple, if that's OK with the inspector - the purple dye has no function, it's just there to show the joint was primed).
Yea, the cow changed a lot of things around here. But I know from installing my a/c units on the other side of the yard, that pvc conduit is acceptable. I imagine, though, there's not much call for it, since most services are overhead and most garages seem to be feed with the direct burial stuff.
As strict as the electrical codes are here, there still seems to be a lot of electrical fires on the news.
Rich-
It was me that said about using the conduit glue. Just works better for me- I have better luck with it. But any PVC cement will work.
"As strict as the electrical codes are here, there still seems to be a lot of electrical fires on the news."Probably caused by the overly strict codes.So strict that it just a pain and expense to follow them that many people don't follow them.And when they don't they don't even bother (or understand) the basic requirements.A while back some one from one of the toneyer subburbs was looking at updating a bathroom. No major changes, but there would be minor plumbing and electrical work.Absolutely no owner work. And hard and expensive licensiing requirements that few contractors would legally work in the area. So all of the work was done under the table.I understand that the big box stores are full of Romex altthough it is against the code.
Edited 6/6/2005 9:43 am ET by Bill Hartmann
That's right, romex is readily available, even though it is illegal. EVERYONE I know that does a kitchen remodel or a basement finish does not pull a permit. I don't even think they consider it. Inspectors do not come around and look, unless a neighbor calls on you, which is rare. And so the contractors do the electric themselves instead of using a licensed electrician, which you are required to do in Chicago.
I have to say, though, I'm glad for the codes here. When my house was remodeled, the piping the electrican did I'm sure was much more expensive than running romex. But when I go look at people's houses in other areas, with all that romex dangling from the basement ceiling, it seems like it would be so easy for a kid to pull on it, a mouse to chew through it in an attic full of insulation, or a nail to go throuhgh it in a wall. Also, my electrician was able to pull new wires through some pipes that were still in great shape after 70 years.
I'd recommend larger than 3/4. It's amazing how a cable can tie itself into knots inside a conduit.
the only different between pvc and gray is the gray is UV protected. But I would use 2 inch pipe so if you need to add later it will be there.
I don't see a problem.
1 and a half inch is the absolute smallest I would use anyway.
BTW: You can get 1" grey pvc conduit with sweeps. Maybe even 3/4"
A person with no sense of humor about themselves, has no sense at all.
I ran 260' of ¾" pvc today- sweeps are available, but I just use a propane torch and bend the conduit as needed,where needed.
You can form sweeps in PVC conduit by using heat. The pros use what they call 'hot blankets' to soften it up, but you can do the same thing at home with careful use of a propane torch. You have to keep moving the torch back and forth to evenly heat the conduit, keep it far enough away so you don't char it, and heat it just enough so it becomes plastic and not so much so it turns into a puddle of goo, but you can get the hang of it with a little practice.
Since this conduit is for a TV coax and possibly a telephone wire, the electrical code requirements are pretty minimal. About all you have to worry about is keeping them away from any 120 or 240 volt wiring.
First, thanks for all the great advice.
I'm thinking now, that as long as I'm doing it, I'd put in an extra pipe in case I wanted to pull some new 120v or 220v wiring at some point. Can I put this pipe right next to the pipe for the coax and telephone?
Another question, if I go with a larger pipe, like 1 1/2", which would probably make it easier for pulling, am I going to have a problem reducing it where it meets the j boxes on either side? Seems like this might cause a snag point for wires being pulled.
Yes you can run another conduit right next to this one.But if it is for120/240 it must be approved electrical conduit."Another question, if I go with a larger pipe, like 1 1/2", which would probably make it easier for pulling, am I going to have a problem reducing it where it meets the j boxes on either side? Seems like this might cause a snag point for wires being pulled."I don' tknow what you are going to be using a j-boxes. But typically you would use conduit body to make the sharp turn from vertical to horizontal to go into the building. You would pull wires from conduit body to conduit body. Then will have relatively short wires that you feed throug the body into the sturture.
The depth requirement (or the thickness of the conduit) for high voltage is different than for low voltage. So you can put them both in the same trench only if a) the trench is deep enough; or b) you use intermediate wall conduit.Now I don't pretend to understand the shielding aspects of conduit, but I try to keep all my TelComm lines at least 12" away from high voltage lines. In fact, I try for a different stud bay (though not relevant here). 12" in the general recommendation from the trade association that sets standards for things like Cat6 and Cat5e. Plus I figure it is a good idea to limit the opportunity to send high voltage down the telcomm line and zap my Gigabyte switches.
Luka- Just FYI- I can get it here on the right coast all the way down to 1/2" w/sweeps at all the big boxes. Almost too small to be of any use. Worked OK for the 3 conductors needed to run my flagpole light about 50' though.
I concur with your assessment. My minimum is now 1" after pulling too far in some 3/4 ". 1.5 would be even better. My neighbor who is a master electrician flat out refuses to pull in new conduit unless he has installed it. Something to be said for that I think.
Yup.There's a reason pvc conduit comes with the bell shape on one end.Put it all together with the bell headed the same direction on each piece. Then pull from the correct end, and you don't have to worry about reaming out the ends of the pipes as you put them together. There will be no place for the wire to snag.
A person with no sense of humor about themselves, has no sense at all.
Conduit for electrical must meet minimum depth requirements. It gets a bit confusing, but I think it's 18" unless protected by concrete.For your own benefit (not a code point, AFAIK), try to maintain 6" or so of separation between the conduits for most of their run. They can terminate on each end right next to each other, but keeping them apart in-between reduces cross-coupling and resulting noise on the low-voltage lines.
You are correct on the 18" requirement for electrical conduit where there will be no vehicular traffic. Crossing under a driveway, paved or gravel requires a 24" depth minimum Service entrance cable in underground conduit is generally required to be at 30" minimum or the local frost depth, whichever is greater.
For general information a manufacture 90 in conduit has a radius turn, and is simply called a ninety. Asking for a sweeping ninety or sweeping ell will get you an extremely long ninety. These are much easier to pull through, but if you are trying to land them inside a wall, can require extensive planning and a lot more excavation. They are double the length and turn radius of a standard ninety, and more than double the cost.
Dave
"Crossing under a driveway, paved or gravel requires a 24" depth minimum Service entrance cable in underground conduit is generally required to be at 30" minimum or the local frost depth, whichever is greater"
Are these some kind of local codes ? In table 300-5 (of my 1999 NEC - don't think it changed) the requirement under a driveway of a house is 18". And I believe that applies to service entrance cables as well. I can't find anything in the NEC about 30" or the frost depth.
I used the 30" depth as service entrance , because the local utility requires it, and it is the local frost depth.
Going under a residential driveway at 18" is allowed in table 300.5 of the 2005 NEC for one and two family homes used for dwelling purposes only.
To me that is a little shallow unless the pipe is punched through undisturbed soil. I have seen driveways trenched and backfilled with the spoil by both homeowners, builders and electricians. Small ditchwitch type burials suvive at that shallow depth because they don't recieve the full weigth of vehicular trafic crossing them. Move up to a backhoe bucket width and the weight of compaction at the bottom of the trench approaches the per square inch weigth of the vehicle tires crossing it. Make that vehicle a dump truck or concrete truck operating in the area of new costruction, and you have the potential for crushed and/or broken conduit.
Always remember the NEC is the minimum acceptable standard in most communities.
If you can do better for exactly the same cost, why not?
Dave
I'm switching my service from overhead to underground right now, and, sometime in the future, I plan to relocate the driveway over the top of this conduit run. I rented a backhoe and went down about 3 feet, used Schedule 80 conduit (even though schedule 40 is allowed - hey, even direct burial of the cables is allowed by the NEC), spread 4 yards of sand on top, and am backfilling by hand to keep the rocks out.
So I agree with you about minimum standards and overbuilding. My comment was just that when you are talking about an electrical subject and you use the word "required", most everyone will assume you are quoting the NEC.
Your comment about the concrete truck rolling over the new trench and the psi at the bottom being almost equal to the truck rolling directly over the conduit was something I hadn't considered. I wonder how long the dirt has to be in there before most of the load transfers down from the top in the normal cone-shaped pattern ? I guess somewhere between one rainstorm and 100 years.
If you are going to pave over the trench or not, I would do the backfill on both sides of the driveway first. In the driveway area do you fill with sand, letting the fill on both sides act as a bulkhead. You can wet the sand down and use a plate compactor to achieve pretty good results. At 8-10" from grade you install a geotextile fabric and finish the fill in crushed stone and the plate compactor, using at least two lifts.
You can save yourself some $$ by just using schedule 80 at your sweeping ells and up to the meter and pole or transformer pad. That is where the extra strength is needed when pulling in service cable. The straight runs between pulling points get very little stress place on the conduit unless it unrestrained. A foot or so of fill over the straight runs is about all it takes to keep it from buckling.
Look at table 300.5 and see what a little concrete in a driveway does to protect your UG service.
Dave
OK, but your comment about the psi at the bottom of the trench makes me happy I used schedule 80 all the way instead of schedule 40 !
OOPS! My reply to your orig. req. for suggestions did not go to you as I had planned. Please see response # 20 of this discussion.
Regards!
Use big conduit, and carefully ream the inside of the ends before you put it together. Doing it yourself, spend an extra few minutes with sandpaper getting them really smooth. Don't use too much glue, never let any get inside the conduit. Code says you can have up to four 90 degree bends, but for DIY, two is safe and three can be marginal to pull. Since this is a long run, pick up a quart of pulling lubricant to make it easier. As for changing sizes on the ends, put a conveniently located big box for pulling on both ends, with the right size holes for all the various conduits that need to attach to it.
-- J.S.
For low voltage, I think 1" is a good size. It isn't big enough to be real expensive, but it'll hold alot of RG-6 coax and CAT5 twisted pair. I have a 160 foot run of it out to my TV antenna.
BTW, the easiest (and most fun) way to pull wire through a long run is to suck a conduit piston (a.k.a. "mouse) through the run with a shop vac. The mouse pulls a lightweight string, which you use to pull a rope, which you use to pull the wire.
BTW, the easiest (and most fun) way to pull wire through a long run is to suck a conduit piston (a.k.a. "mouse) through the run with a shop vac. The mouse pulls a lightweight string, which you use to pull a rope, which you use to pull the wire
a.k.a. "sammich bag" if you don't have a conduit piston.
Dave
An unsolicited suggestion, if I may, from one DIY'r to another.
A few years back I was faced with the prospect of purchasing (12) 90 deg. PVC elbows to protect and guide some 3/4" ID PEX tubing up through a poured concrete floor to my supply & return manifolds for a Radiant floor I put in. After a short learning curve and some oven mitts, I got quite good at hand bending precut lengths to what I needed. I preheated the pieces in the electric oven in the kitchen and just bent them on the ceramic floor! No flames, very little smell (once you get the times & temp. down pat) easily available & much less expensive than store bought! If you plan it right & are able to use offcuts which include the bell end you don't need to buy the straight connectors even. (I needed some as my runs were very short & req'd little conduit)
If you start with precut pieces a little long, you can always cut the finished 90 to just what you need. (A pipe cutter with a plastic cutting wheel makes short work of square cut ends, much improved over a saw, I've found. A hand deburring tool usually found at machine shop supply places for deburring steel is the best I've encountered for taking edges off piping of all sorts, ID's & OD's in copper, plastic, steel, brass, you name it!
Another suggestion would be to get some wide, brightly coloured plastic flagging tape (like the wide WET FLOOR or WET PAINT or CRIME SCENE!) & bury it above your conduit when you backfill the trench. If you keep it up 12" above the conduit it serves as a warning should anyone ever need to excavate over your buried line in the future. (Although its code required to ID buried power lines where I live, I still think its a good idea!) I'm not usually one to embrace all the things that the inspectors demand, but when I put in a 300' buried power line myself I put in 2 of the required burial tapes, 1 just below grade above the trench and the other just about 18" above the line itself.
Do it right, do it once, do it to last forever.
An unsolicited suggestion, if I may, from one DIY'r to another
No offense taken. I see that you are new, but maybe a long time lurker?
I have a Masters Electric license. I am a maintenance tech. for a local utility company, and have operated my own residential/commercial remodeling business for over 30 years, either full or part time. Additionally I have worked as a carpenter and construction superintendent for some 8 different commercial companies locally.
Bending PVC conduit for ells is not an option I care to try, just to save a few bucks. I may use a heat gun on occasions to make minor offsets or kicks in a piece of pipe, but that is a rare occurrence from something unseen in the planning of a job. Both my current employer and my clients find my time more valuable than the cost of trying to make fittings.
Dave
RE: Sweeps
You should be able to find 3/4 PVC sweeps at the local Depot. We buy them there by the carton. They should carry 45 and 90 from 1/2 upward, but look in the electrical section.
Having said that, I caution that it depends on the Depot. Some don't carry much at all.
Things I learned the traditional way...
Go bigger than you need - makes for an easier pull. Double it - makes for expansion for later. We pull a pair of 2" to the garages for phone/signal and electrical.
The ToolBear
"Never met a man who couldn't teach me something." Anon.
I'll go have another look. I've been known to walk into stuff and still not find it.
@@ I'll go have another look. I've been known to walk into stuff and still not find it. I've done that. However, wiring the office side of a warehouse renovation, I found that the Corona, CA HD was lacking some very common items - such as 1/2 and 3/4 LBs and more. It is in the system, but your HD might not have.Pull Bigger: When I was rewiring some gun clubs, the cheapest hole I could find per foot for my phone, CCTV, etc was that 3" COEX drain line, so I ran the signals in COEX chases with irrigation boxes for pull boxes and two pull cords in the line. Inspector could care less. Low voltage stuff - not inspected. Just keep 12 to 24" from the AC lines to avoid interference. The feeders were 4/0 triplex UF with warning tape above them in the trench.SonInLaw's sparky speced 3/4 for a 100A feeder to the garage. Rather snug. Our Habitat homes have a pair of 2" formed into the slab in the garages. We dig the trench later and hook them up.Tip: Trying to find the run of the line later. Take lots of pix. In addition, we put white PVC caps on scrap 1/2 P40 conduit and drive those into the ground along the run to locate them - especially buried boxes. They are normally below lawn mower height. Nice to engrave how deep to dig on the cap.The ToolBear
"Never met a man who couldn't teach me something." Anon.