450' wiring conduit -how to assemble?

[hr3]

Ihfarm,,

A master electrician here,,been one for several years.. Be very cautious here asking for advice,, there are lots of ways of doing things,,,but only one way of doing it right,, and easy.. speaking of easy..just think of sliding 10' of conduit 300 some odd feet up your trench over your wire.one piece at a time..then glueing it to the piece already in the dirt..dosn't work never has been easy...

Put all the pipe together outside the trench and then back fill..don't forget the marking tape about 6" down from the surface.. Your expansion joints will go under your meter..none on the pole...speaking of the pole...Oooo you didn't spec. if it was from a pole or an underground transformer... Your local utitily will be able to give you the specs they want for each..and the will tell you what size conduit to use also..me i'd go with 2 1/5 inch..a bit more money but it will make it easyer to pull in and also down the line it will be easyer to pull the old out and replace it,,,I maine where I am the utility wants us to use 250 mcm not 4/0 over the 300 foot limit..voltage drop over your long run should be figured...again your utility will help you with that..

As for puling it in the pipe when your done..drop me a line I think my mail in in my profile...it's easyer than you think..

 

[tommu56]

I meant slip joint - I think. We have lots of freezing/thawing and ground movement.

Thanks,

Note the "slip joint" will not prevent the wires from pulling out of the terminals.
It would let the conduit move but were does the wire get the slack?
The only way to put a riser in is to provide for good drainage and make sure the fill is compacted correctly.

If you run it in the inverted L the horizontal run will give you the play you need if the ground heaves.

The pvc pipe glue and the pvc conduit glue is almost the same except the conduit has some Grey filler material in it the solvent to do the "weld" is the same.

Price out the wire as USE cable as direct burial and the THWN wire with the conduit with out your labor the THWN might be cheaper.

The tricky part of pulling in the wire is making up the head to keep its size down and still provide for a god connection to the rope.

The hard part of pulling is the pull.

tom

 

[Illini22]

usually mule tape has footages on it but iwouldn't pull that far with it. use it to pull your rope or winch line in with the mule tape. Then get a kellum grip or chinese finger to put over the triplex wire or just the nuetral and cut your phases back. if you are pulling far with bends we use steel because the rope will burn right through the bends if you know anyl lineman they might have some pipe dollys to help with the pull if you are not right above the pipe and are pulling at an angle.
at the utility I'm at now we use 3 inch for 4/0 and 350 Al.. I've been installing overhead and underground distribution for 25 years direct bury and the last 8 years in pipe. In my opinion its far more expensive to install and causes 10 times the damage when it gets hit, You will be buying a new transformer when the cable pulls the bushings out, new service entrance breaker box and a whole lot of cable. when direct bury gets hit your damage is very minimal, just a few shrink tubes a couple splices and a few feet of wire. no matter which way you go remember to put frost loops in the cable in your service entrance as it comes out of the pipe. their bends back and forth like a couple of s's. If your pipe drops or the overdig on a foundation settles the slack in the frost loops keeps your raceway from pulling off the house.

 

[Uncle Doug]

Another thing to look at is do you need a 200 amp service to your barn? Will you be using a electric welder or some other large power unit? Can you get by with a 100 or even 60 amp service?

My barn is 300 foot behind my service drop. I ran only a 60 amp service to run some lighting and fans. It would require much smaller wire and conduit at a greatly reduced cost.

 

[EddieWalker]

.. speaking of easy..just think of sliding 10' of conduit 300 some odd feet up your trench over your wire.one piece at a time..then glueing it to the piece already in the dirt..dosn't work never has been easy...

There are those what will spend a week working on making something easy, while there are those of us who will just do it and be done with it in a day.

Nobody is saying to unroll the wire in the trench. That would be silly. Unroll the wire next to the trench where it's easy to get to and walk the pipe to.

Those ten foot sections don't way anything and once you get the wire through them, the wire will just lay there while you walk the pipe to the middle. Each pipe after that will be a shorter and shorter run. If you can get 20 foot lengths, it will go even faster. The glue will take all of a few seconds each time and you'll have to do that no matter how you do it, so gluing them together really doesn't matter either way.

When I installed my 6 inch water line to my house and into my land, I got bids for it and was quoted $30,000 for labor and material. I spent about $8,000 for the materials and did the work myself over four days. It wasn't easy, but I only worked on it half a day and did other things when it was too hot. This was in August when I did this.

You can do it, and if you need to take a break, them by all means, take that break. Like most anything, it's usually allot harder thinking about how tough it's going to be then it actually is.

Eddie

 

[CurlyDave]

Eddie is right.

I have a hard time imagining someone assembling conduit in a trench when right next to it is nice flat ground.

Put it together on the ground and push it into the trench at the end of the job.

And, if you glue those 10' sections together you can walk 20' or even 30' sections down the wire.

 

[flusher]

This is the continuation of my on going project to get power to the barn. To date, I've had two estimates that differ by $800 and have now called the power company for their advice. The power company, based on a phone conversation, is going to recommend a new 320 amp meter base and a 200 amp cutoff at the meter. For background the power comes into the garage, where the meter is located. 200 amp service runs under ground into the house.

The first bid was no conduit, 2/0 feed from a breaker in the garage panel. Second bid is for conduit, but basically the same setup. The power company says no less than 4/0 and in conduit for our soil conditions (rocks).

The cheapest trenching is $1/foot, but I've got a BH (why I'm in this forum). So I'm going to dig the trench and lay the conduit. I've search the board and found one good discussion, but I unclear of how I should proceed. Do I dig the trench (12" bucket) to the required 2' depth and then start assembling the conduit (2" 10' sections) on the ground, then lower them into the trench. Or do I glue them up in the trench? Should I dig 10', install a section (capping it to keep the dirt out) and back filling as I go?

I'm sure the part of the higher priced bid was for using the guys cable pulling equipment, because he mentioned the distance and the need for specail pulling equipment. Am I going to need him to pull the cable for me or will a rope, cable lube and my back be able to pull 4/0 that far?

Any advice appreicated. If I haven't made it clear, I'll try to answer questions too.

Thanks,

Here are a few images taken when my 220V/200A service was installed a few years ago. The PVC conduit was about 350 ft in length, glued together and buried. Two 4/0 and one 2/0 cables.

The input end:

The output end:

Fiberglass pulling rope

Electric winch mounted in the trailer hitch receiver

Need a lot of pulling lubricant

The cable pulling job took about 4 hours doing it this way.

 

[schmism]

450' your starting to push what the power company (in my area) wants to run for service drop.

4/0 wire is HUGE, expensive and requires LARGE conduit

On the other hand you may inquire about going high voltage with a much smaller conduit size and a small padmount transformer next to your meter base.

Per my power company the bid came in slightly lower (within a few hundred) for the Highvoltage option.

 

[2manyrocks]

Pulling 450' feet of wire through 450' conduit. 1) Do you have a long enough piece of adequate rope to pull the entire wire through this length of conduit? 2) Is the conduit oversized enough that the wire isn't going to bind up? 3) do you have some mechanical means of pulling the wire?

A ride on trencher would be much faster than a backhoe, but only you can weigh out the cost and time.

Maybe it was explained before and I missed it, but is there a reason the power company won't run an overhead line?

 

[bitternut]

I did the exact thing that you are planning. I ran electric service underground from a new pole at roadside to my barn 450' away. I had a guy dig a trench from the meter channel location at the corner of the barn to the new pole location. It was dug 2' deep and all spoils were placed on one side of the trench. The power company told me that if I did the install to their spec's they would take ownership of the line to the meter which would guarantee any repairs of the line would be their responsibility. To me that was a no brainer. Because of the distance they required that I install 4\0 2\0 triplex aluminum underground wire in 3" conduit and that I run a double run to insure that I got 230 volts at the meter. I purchased two 500' spools of the wire.

I glued my pipe sections together and slid it along side the clean side of the trench as I went. I have a large sliding door next to the corner of the barn where the meter channel was to be located so I had a stand set up where I could do my gluing from under cover. I also bought a box of poly baling twine to place in the conduit as I glued it up. I made up a ball of the twine and used a long piece of stiff wire to pull the twine through each section of pipe as I went. The glue up went very fast and was easy to do. Others have stated that you could pull a string through the pipe with a shop vacuum but as I had no experience doing a job like this I had not heard of it. My method was slower but absolutely fool proof. After the two runs of conduit were all glued up and the pipe was in place next to the trench I took the bucket off my tractors loader and mounted a spool of wire on the fel using a pipe through the spool and the loader arms. I then also used the baling twine to pull a 3/8" poly rope through the pipe which was used to pull the wire through. Once the pulling rope was in place I had my helper feed the cable into the pipe and control the feed of the cable. He also was placing some lube on the cable that I bought for that purpose. I then sat down at the barn end of the pipe and started pulling. It was a piece of cake. I could not believe how easy the pull was. My only mistake was that I did the pull backwards. My barn is higher than where the pole was and I was actually pulling the wire uphill. Duhhh.

I also pulled another length of the polly baling twine with the cable that I left in there just in case I might want to pull something through for whatever reason in the future. As long as I had the trench open I glued up a length of 2" conduit and pulled through underground phone line that the phone company gave me for free. Once everything was all glued up and full of wire I flopped things into the trench, put on my sweeps and frost loops, got it inspected,etc.

That was over fifteen years ago and I could not be happier. Oh and by the way the guy that told you that you needed special equipment to pull the wire is full of crap. The power company told me the same thing. I was a nervous wreck doing the install because of what they had told me of how difficult it would be to pull the cable. All I needed were my two hands and my feet propped against the end of the pipe.


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