Connecting Pull Rope to Multiple Conductors

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  #1  
Old 01-14-14, 03:25 PM
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Connecting Pull Rope to Multiple Conductors

I will be pulling 4 conductors in 300' of 3" conduit with two 90 degree sweeps. With the proper amount of lubricant, the pulling tension is estimated to be about 400 pds. Do I need to invest in purchasing a basket grip for the job (I'll never use it again), or is there a way I can manufacture a reliable connection myself? If purchasing a grip is the only way to go, will a basket weave type grip work to pull multiple conductors and, if so, what size of grip do I purchase if I am pulling 3 conductors with a diameter of .681" each, and 1 conductor with a diameter of .373"? Thanks.
 
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Old 01-14-14, 03:35 PM
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Those are 350 cables?
At work we would fish a rope into the pipe, then strip off a foot or two of casing, take a hacksaw and cut off half the strands of wire on each cable, then bend the strands through a loop in the rope, and then squish the bends down and tape the crap out of the entire head.
Placing your wires together and squishing the bends is important to be careful with so you don't have a wad of tape and wire which does not fit nicely in the pipe.
 
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Old 01-14-14, 04:51 PM
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Yes, I have three 350s and one 1/0 (all aluminum) to pull. It's outdoors with both ends of the conduit exiting open ground, so I can easily build a set up that allows all four spools to feed straight down into the first sweep.

I am still thinking about how I'll do the pulling. I have a light duty winch with about 100' of cable capacity that I can set up on an A-frame above the riser of the second sweep, but I'd have to buy 200' more of cable and off load the cable from the winch twice to get the job done.

Because I have room to drive a tractor more than 300' beyond where I am pulling, I was thinking I could just install a good size roller (or two) on a frame of some type, run the pull rope over the roller(s) and then attach the rope to the tractor. Then I'd simply have someone drive the tractor slowly away, making certain that the roller/frame assembly remains firmly in place. The tractor has a hydrostactic drive, so it can move in a super slow, super controlled fashion. I've got the unobstructed room to work, so I have a hunch that the roller/frame and tractor set up should work well, so long as the frame counters the forces involved properly. As I said, the pulling tension probably be won't be more than about 400 pounds, so it shouldn't be too difficult to build an effective roller/frame assembly.
 
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Old 01-14-14, 05:00 PM
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I'd use the winch and a rope. Put a loop in the rope, pull with winch 100', remove winch, repeat.
I just have visions of snapping the rope with a tractor.
On simple pulls such as yours we often just use manpower, 2 guys feeding 2 guys pulling.
 
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Old 01-14-14, 05:13 PM
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That's going to be a little beyond two guys pulling.

The toughest part is anchoring the roller assembly. It's going to want to either slide towards the tractor or fall over.

You can use rope to pull too. I have 250' coils of 5/8" rope which is pretty effective to pull with. Has a little give too so you know if the wire is binding.
 
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Old 01-14-14, 06:06 PM
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For pulling without a grip, drill a small hole through each conductor and run some tye wire (similar to what they use for tying rebar together) through the holes. Twist the tye wire many times untill you end with a loop on the end you can attach to the rope. Do this for each conductor.
 
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Old 01-14-14, 06:10 PM
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For rope I'd use something like this.

New 1" x 300' Double Braided Cable Pulling Rope | eBay

I'd attach to the wires with pulling fingers, something like this.

GRIP KIT,WIRE (629) - Greenlee - Made for the Trade™ 783310318552

I wouldn't use a tractor to pull the wire. I've seen trucks and tractors used before to pull wire, but nothing works as well as or gives the operator the necessary control for a smooth pull as a tugger. Usually tools like this can be found on a rental basis.
 
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Old 01-14-14, 06:35 PM
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Wow Joe....that is some big rope. 10,500 lb. work limit.
 
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Old 01-15-14, 10:02 AM
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I appreciate the concerns about using tractor power to supply the pulling force. With hydrostatic (fluid) drive, the tractor really can creep at the rate of a typical winch. Also, the transition from a state of rest to the beginning of movement is totally smooth.

Although I can certainly use just the winch, I would have to stop the pull numerous times to off load pull rope and reattach it to the winch hub. My preference would be to not stop the pull once it gets started.

Another thought I had was to use the winch as a friction hub while the tractor pulls. With the winch in free spin mode, I could wrap the pull rope around the the hub a few times and then attach the end of the rope to the tractor. During the pull, the rope would off load at the same rate as it gathers on the hub. I could also control the pulling force very well. With less than 500 lbs of pulling force necessary, I'm thinking that this set up ought to work fine.
 
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Old 01-15-14, 03:19 PM
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Tolyn,
That is a great idea! Have you had many breaks doing it that way? I'm going to claim that idea as my own when we do some feeder cables at the site I'm on in the near future lol.
 
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Old 01-15-14, 04:23 PM
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Wait to see if it works!! I'll report back in a few weeks when I've tested it.
 
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Old 01-15-14, 04:28 PM
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Online Supply House Recommendations

I need to buy some items like wiring trough boxes, splice kits for larger conductors, power distribution blocks, contactors and the like. I often get stuff from Grainger, but I'd like to know if there is another online source with a comparable selection but better pricing.
 
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Old 01-15-14, 05:11 PM
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I'd recommend checking out your local supply houses and see if they will sell to the public first. As slow as construction is, I'd bet at least some of them would be glad to have your business. I usually reserve buying online for specialty items I can't find locally. Remember, Google is your friend.
 
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Old 01-16-14, 07:09 PM
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Never had one break. (knock on wood) You can also twist each wires tie wire to form a single twisted wire to attach the rope to. Next time we do it I will try to remember to take a picture or two.
 
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Old 01-17-14, 06:40 AM
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For pulling without a grip, drill a small hole through each conductor and run some tye wire (similar to what they use for tying rebar together) through the holes. Twist the tye wire many times untill you end with a loop on the end you can attach to the rope. Do this for each conductor.
That certainly is an interesting method, I'd love to see it done sometime. How far back from the end of the conductor do you drill the hole? Let's say you are pulling 3/0 copper THWN, how far back do you drill? Also, let's say you are pulling 4/0 or 750 MCM Al XHHW, how far back would you drill?
 
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