Replies

1. 
   Bill_DeBell | May 16, 2000 04:13pm | #1

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   Alan, I recently supervised a job where this was done. It is impossible to pull through the 90's. You have to do a section at a time and then slide over the 90, then do the next section. It is a bear. Try coiling the wire into a small circle and slide the 90 on that way. This was how we did it but it took more than 1 man. Good luck!
   Bill

2. 
   Guest_ | May 16, 2000 04:20pm | #2

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   Not that it matters, but doesn't code require you to make up the whole conduit run before you pull? One thing that can help is to lube the inside of conduit by pulling a lubed rag through before the cable.

1. 
   Guest_ | May 16, 2000 04:42pm | #3

   *I just layed conduit for my service entrance. The PUD in my area requires 3" conduit. No more than 3 90's and the 90's must be 36 inch radius. I would consider the 3" conduit. Youre going to have a hell of a time.FWIW

1. 
   Guest_ | May 16, 2000 06:30pm | #4

   *Just did that last summer, about 235 feet of run. The two of us were really tired after that.Here's my advice:Lay the cable in the trench first, with ENOUGH extra at each end (sure be a shame to have to do it all again because you were two feet short!).Pull the conduit over the cable from one end (have a helper hold the cable end for you so you don't just pull that along too). Use a rope looped over the conduit end so that you can pull while walking erect - you really don't want to have to stoop while you are pulling that far. You will also get the best leverage this way, I think.Definitely use the larger diameter and the biggest radius elbows you can use.Start at each end, like you said, so you only have to pull the shortest possible distance, make sure that your conduit pieces are correctly oriented before your thread them on the cable.When you have all of the cable threaded with all of the correct conduit pieces, then go back and glue everything together in the trench. If you lift it up about 4 inches for gluing you'll be able to keep any dirt out of the joint. Be sure to check each conduit piece fits smoothly before applying glue because you may need to 'dress' the male end (if it got banged during threading).Presto. Note that after gluing your conduit will get about 2 or 3 inches shorter for every joint (don't cut things too short while you are going along).And if there is a code that the conduit has to be glued before feeding, be sure to ask the inspector how to do it because I can't imagine how!Oh, yeah, be sure to include a strong twine with your wires in case you ever want to run anything else down there in the future!Season to taste and enjoy!

1. 
   Guest_ | May 16, 2000 07:37pm | #5

   *buy the special wire pulling synthetic twine they sell at your electrical supply store...don't forget your 1 inch conduits .. one for tel.. & one for cable...buy long sweeps instead of 90'sglue all your conduit .. put it in the trench .. BACKFILL THE TRENCH.....lube your cable with the pulling grease.... tie a birdie on your twine and suck your twine thru the conduit with a commercial vacumn cleaner...some people use plain plastic sandwich bags as birdies... tie the twine to your pulling wire / rope..now pull your pulling wire or pulling rope thru the conduit.. which is secured to your bundled cables..the pulling cable / rope is led to a block up the pole or to some fixed object near the electical stanchion...then led by another block to the bumper hitch on your truck....or to a winch.. have someone at the house to feed the cable.. and comunicate with them by walkie talkie or cell phone...start pulling ....with the conduit backfilled in the trench you can exert these kinds of forces...cause these are the forces neccessary to do the job...you're an amateur.. give yourself a break.. buy the larger diameter conduit... and the sweeps...you'll save yourself a lot of headaches..unless you're an electrical contractor and you've done this a hundred times before... but u haven't .. so buy some help...BTW.. some jurisdictions allow direct burial cable in sand bedb but hey, whadda i no?

1. 
   Guest_ | May 17, 2000 01:36am | #6

   *I think you need to talk to your inspector or utility company. I think you're only allowed 360 degree bends total, from termination to termination. I was taught that you glue up your conduit first, you can pull the twine through as you glue it up but not the wire. Also I don't think you're allowed to tape the wires together , but must leave them loose .Better to ask first.

2. 
   Guest_ | May 17, 2000 02:09am | #7

   *I though USE could be buried without any conduit. That sounds alot easier.

3. 
   Billy_Dudley | May 17, 2000 03:15am | #8

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   those guys were right about the 90's. you need a pulling point (conduit "c" body before the last one.
   Forget the truck, go rent a wire tugger from your local equipment rental, they offer much more control and come with lots of pullies and braces to hook it up with.

4. 
   Guest_ | May 17, 2000 04:23pm | #9

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   Thanks so much, folks.

   This is yet another - "I've always wanted to try this"
   project. But it always ends with "Once is enough and I don't ever want to do that again." and call a pro next time.

   I have thoroughly absorbed all of your advices and will tackle this one accordingly.

   First thing I will do is pre cut all of the conduit sections and test fit them.

   If I were a contractor I would be losing money on this job at the pace I'm going.

   One thing for sure is the job would be thorough and overdone in the quality of material chosen.

   Thanks again, and I will check for more feedback.

   Alan

5. 
   Ken_Diamond | May 18, 2000 03:45am | #10

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   Alan

   Follow Mike Smith's recomendations. We've pulled many cables thru conduit and that's how it's done.
   But do yourself a favor and rent a Greenlee cable winch. (We borrow our electician's). We do alot of houses with 500-1000 feet driveways and the Greenlee is the only way to go. (a truck would work, but you would need a straight shot of 1000 feet on the house side to pull the 1000 feet of cable.) The Greenlee is a slip style winch style and does not have to be moved.

   Have fun and use alot of grease and a "chinese" connector to pull the cables-it gets tighter the harder you pull.

   KD

6. 
   Guest_ | May 18, 2000 06:42am | #11

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   Here is my report on today's efforts, which went without a hitch and without using any lubricants or mechanical assists.

   All conduits were pre-cut and test laid in the trench.
   This was to make sure all the 90 degree sweeps would fit correctly and adjust for the different pitches of the three runs of trenches and several sections of 45 degree zig zags near the boxes.

   Very accurate measurements were made of the sections of the conduits and also the length of each trenches.

   The four cables were laid out in a straight line, along the middle run trench. The proper section of the cables for the middle run trench was lined up properly.
   This was actually the hardest part due to the weight of each cable sections.
   I believe 120' of 3/0 copper cable weighs around 60-70 lbs, but it felt like a 100 lbs.
   Unrolling two of these and the 2/0 and #4 cables into a straight line was quite a chore.

   Tied the four cables together on one end with duct tape and shoved the cables through the first section of the 10' conduit to end at the end of the middle run. After getting the conduit on to the cables far enough the expose the duct taped end, the end was weighed down with a heavy cinder block.
   Grabbing the 10 foot section of the conduit, I walked it to the proper point.
   The cables slid through the conduit without any resistance. No need for any lubricant.
   Subsequent sections were "walked" over in order and glued up.

   Sliding on the 90 degree sweeps was not a problem at all.
   Slide on the sweep, then form a loop in the cable and start "rolling" the cable as you slide the sweep along. Works like a charm. I just rolled and slid the section along all the while walking standing upright.

   Once the middle section was fitted and glued up, the starter section from the meter base/main disconnect were fitted and glued up.

   Tomorrow I am finishing up the home run section into the house and expect things to go just as easily.

   Well, except for having to create an opening in the basement wall for the 2" conduit.
   And I am glad I have to wrestle with only about 20' of the four cables through the three LB boxes before dropping down into the fuse panel.

   I would love to return the bottle of the lubricant and see the reaction on the guys' faces. (They did offer to take it back if I didn't use it.)

1. 
   Guest_ | May 19, 2000 09:00am | #12

   *Mike's post #7 says it all.Before you backfill, have you considered burying a warning tape (or whatever is required by code in your area) in the trench? If nothing is required, splurge a couple dollars on a roll of tape.

7. 
   JohnK | May 19, 2000 11:47pm | #13

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   Lonecat's right, code says you have to assemble the conduit entirely, then pull the wires. We usually blow the birdie with compressed air instead of the vacuum. Otherwise the same as Mike.
   John

8. 
   Guest_ | May 20, 2000 04:13pm | #14

   *
   Hello -

   I am sore all over from digging about 200' of trench with a Ditch Witch yesterday.
   But the worst part has yet to come as I need to lay 2" conduit and feed about 120' of four copper cables (for service entrance) from the main disconnect on the outside wall to another wall on the other side of the house.
   (Pulling or feeding the cables through glued up conduit the entire length has been ruled out.)
   I have four 90-degree turns to make, with two 30' runs and a 20' run that makes a couple of turns.
   Once inside, the cable will have to make turns through three 90 degree LB boxes before dropping down into a brand new Square-D 40/40 200-amp panel.
   I am about to do all of this myself and been having nightmares trying to come up with a good system for feeding and gluing up the sections as I go.

   The cables to be pulled are:
   two 3-0 copper for the hots.
   one 2-0 copper for the neutral.
   one #4 insulated copper for the ground.

   I have a bottle of the cable pulling lube.

   I am planning on laying out the cables together and bundling them in sections with duct tape and sleeving on the sections, one half from one end and start back from the other end.

   The concern is the 90 degree sections, which would be a real pain to run along the length of the cables to reach a certain point.

   Since I don't have the trick tools of the trade I'm needing all the help I can get.

   Thanks in advance !

   Alan

9. 
   Guest_ | May 20, 2000 04:13pm | #15

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   Thanks for the great suggestion on a warning tape burial.
   I will do that, definitely.

   I also have been documenting line of sight images
   before and after every step of the way with my camera and will have prints and digital files burned on a CD-ROM. I also have an aerial image of the property that will be marked with the lines.

   I passed the initial inspection yesterday and was given the ok to fill in the trenches.
   He was pleased with the job.
   The conduits and cables were run without any means of mechanical assists, through four 90 degree sweeps and about 100' of distance.
   A friend helped me with dropping the runs into the trench and coax a couple of final connections but the rest was done alone.