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Pulled 130 lbs of wire this weekend

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  • Pulled 130 lbs of wire this weekend

    This weekend, with help from my wife and kids, I pulled a wire bundle consisting of six 4 AWG conductors and one 8 AWG EGC through about 110 feet of 1 1/4 EMT with about 800 degrees of total bend. To stay within the NEC requirement of no more than 360 degrees of bend between pull points, the total run was divided into three sections. There is a subpanel (not the critical loads subpanel) with a 60A breaker serving as an AC disconnect between the middle and one end section, and an 8" square box between the middle and the other end.

    This insane conduit run was necessitated by the placement of my equipment shed outside, the run of conduit along a chain-link fence, the need to go over a doorway in my garage, and the best route I could figure out in the ceiling of my basement. The electrical panel is unfortunately on the other end of my house from where the equipment shed had to go, and the solar array is 150 feet further away from the electrical panel. (For that run, less copper was needed because I'm running at around 440 Voc.)

    I needed two hots and a neutral from the main panel to my Outback Radian in the shed, and two hots and a neutral back out again to the critical loads subpanel that sits five feet away from the main panel. I'll be moving my selected branch circuits over to the subpanel soon--fairly simple since the wires go straight down the exposed basement wall to the main panel and I'll just have to move a few of them over. No splicing needed--the branch circuit conductors will be shorter after their move.

    I oversized the wire because I don't want the lights flickering every time the well pump kicks on or someone uses the microwave. It doesn't take much resistance per foot to get voltage drop at 20 A with 220 feet from main panel back to the subpanel.

    What a project! I fashioned an eye splice in a 3/8" twisted polypropylene rope and attached a "Chinese finger" pulling grip to it. I wrapped four of the 4 AWG wires together with black tape, slid the grip over them, and taped the two other 4 AWG wires and the EGC to the bundle a few inches further from the end, staggering the points of attachment so there was a nice taper. The whole thing barely fit into the conduit, but lots of lube, one person pushing the bundle in at one end, and me pulling with most of my 200+ lbs. on the other end got the job done. I was actually surprised at how well it went.

    By the way, the NEC limit for 1 1/4" conduit fill is seven 4 AWG conductors. I was just a little under the limit, and that's without considering the EGC differently from a conductor. But with a 50 A breaker at the Outback Radian, these big wires are not going to get near their 90 degree C temperature limit.

  • #2
    Not a 'trick question', I really don't know. What is the downside in this situation (besides the obvious cost) of up-sizing the conduit to 2" or even more to facilitate 'insane' pulls? Or, perhaps more relevant, would up sizing the conduit even result in a detectably easier pull? Seems people are more than willing to up-size conductors but not so much with the conduit. I ask because I will also need a run from the NW corner of the property to the SE corner with a vaulted ceiling, basement-less house smack dab in-between - probably the main thing that keeps me from pulling the solar trigger.

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    • #3
      2" electrical PVC is available from all of the big box stores and does reduce pull forces and cost is not too great. Southwire has a great free excel based pull calculator and it is surprising how much pull forces are reduced by increasing conduit size - because - the bend radius increases. Couple of things make installation easier.

      - Greenly PVC blanket allows you to do custom large radius bends (I got mine on ebay for a bargain). Once you have one of these - you will never not want to have it.
      - your entrance and exits should be pre-made large sweeps. I used 24" schedule 80's to meet the requirements here.
      - align the bell couplings so in the direction you are expected to pull you never go from larger to smaller - always go from smaller to larger in the pull direction. I also beveled my ends using a 2" reamer so if I every had to pull back out the wire did not have a square end that could scrape the insulation.
      - I made a super low cost joiner tool. Clamps on both ends and you just ratchet those pieces together. Ensures a fully seated connection solo so you don't need a friend/helper. (see pics).
      - Use Simpull wire and no lube needed at all. That stuff is amazingly slick.

      https://flic.kr/p/PBvw7L
      https://flic.kr/p/P7ds8f

      How I built a combiner for 3" but I also made one for 2" - same setup. My first 2" one was just some low cost 1" ratchet straps - which also worked.
      Last one shows a 6' radius bend both done incorrectly and correctly.

      https://solargroundmount.blogspot.co...?view=magazine
      https://solargroundmount.blogspot.co...?view=magazine
      https://solargroundmount.blogspot.co...?view=magazine
      Last edited by tyab; 10-16-2017, 06:36 PM.

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      • #4
        Originally posted by AzRoute66 View Post
        Not a 'trick question', I really don't know. What is the downside in this situation (besides the obvious cost) of up-sizing the conduit to 2" or even more to facilitate 'insane' pulls? Or, perhaps more relevant, would up sizing the conduit even result in a detectably easier pull? Seems people are more than willing to up-size conductors but not so much with the conduit. I ask because I will also need a run from the NW corner of the property to the SE corner with a vaulted ceiling, basement-less house smack dab in-between - probably the main thing that keeps me from pulling the solar trigger.
        I wanted metal conduit for a couple of reasons, and the biggest I could bend by hand was the 1 1/4 EMT. Doing 90-degree bends with my Klein Tools blue monster was right on the edge of possibility by myself. To avoid kinks, I needed a little shove near the end by someone else while I kept my full weight on the pedal.

        I'm happy with how it turned out. The pull was easier than I expected. Definitely needed a second person shoving that wire bundle into the conduit as hard as they could, though. And definitely use a polypropylene pull rope rather than trying to pull with the fish tape.

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        • #5
          Thanks to you both. So in each case, PVC and metal, the biggest downside is just bending the stuff, and the availability of tools to do that. Guess I'll make sure they are accounted for before just deciding to go bigger.

          The 'funny' part is, when we first bought the house, I contracted out a major upgrade to the water line and electrical in the back yard, bringing in 240V for a hot tub and several 20 amp circuits. It was my understanding that they were going to drop a conduit in the trench that would have run to within 20' of where I need it, but about a month after the trench was filled,compacted, and a full paver patio surface had been laid down over the entire area, I noticed it wasn't in the final billing. When I asked, after they conferred for about a week they came back with "Oops, we forgot."

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          • #6
            Originally posted by AzRoute66 View Post
            Thanks to you both. So in each case, PVC and metal, the biggest downside is just bending the stuff, and the availability of tools to do that. Guess I'll make sure they are accounted for before just deciding to go bigger.

            The 'funny' part is, when we first bought the house, I contracted out a major upgrade to the water line and electrical in the back yard, bringing in 240V for a hot tub and several 20 amp circuits. It was my understanding that they were going to drop a conduit in the trench that would have run to within 20' of where I need it, but about a month after the trench was filled,compacted, and a full paver patio surface had been laid down over the entire area, I noticed it wasn't in the final billing. When I asked, after they conferred for about a week they came back with "Oops, we forgot."
            So I guess they went with direct burial type cable instead of using a conduit. The cable is more expensive but you save by not buying and bending the conduit.

            Direct burial cable works just fine if it is installed deep enough and protected from being crushed by something heavy on the surface. I believe a lot of POCO's install direct burial cable without any issues.

            Since I will be getting a new service that will run about 185 feet to my new home I expect it will be direct burial cable. Hopefully that will happen in the next week or so.

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            • #7
              Originally posted by AzRoute66
              The 'funny' part is, when we first bought the house, I contracted out a major upgrade to the water line and electrical in the back yard, bringing in 240V for a hot tub and several 20 amp circuits. It was my understanding that they were going to drop a conduit in the trench that would have run to within 20' of where I need it, but about a month after the trench was filled,compacted, and a full paver patio surface had been laid down over the entire area, I noticed it wasn't in the final billing. When I asked, after they conferred for about a week they came back with "Oops, we forgot."
              I learned long ago, if you don't do it yourself, put it in writing, and check up on everything, frequently.
              Mostly they don't go back and check the work against the original requirements; QUALITY isn't taught
              in school. I have SO MANY stories. Bruce Roe

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              • #8
                Originally posted by bcroe View Post
                [...] Mostly they don't go back and check the work against the original requirements; [...]
                Yeah, I can't put the blame on them, this was definitely not a 'requirement', written or otherwise. I came home from work and saw that they had trenched all the way to the north side of the north patio, which surprised me as I thought that part of the patio would be powered via overhead conduit since they had to go there to install the ceiling fans/lights anyway. I saw that as an opportunity and asked the electrician if they would drop in the conduit. He said sure, and asked how big. I said I had no plan, but something big enough to handle a full RV service or moving the hot tub to that part of the yard would probably cover everything. He said no problem, and that was the 'requirement'. I was out of town the next week and when I returned the trench was filled, compacted, and paver laying was in full swing. Frankly, at that point we had both 'forgot' about the whole conversation.

                I couldn't even tell you if what they put in was direct bury or in conduit... I was a working dog, and it was always easier to find spare cash than spare time.

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                • #9
                  I have never even tried to bend EMT over 3/4". For underground PVC is cost effective but a number of folks on the mike holt forums for commercial projects use RMC sweeps for entry/exits on large bundles that transitions to PVC. On my system, everything above ground is EMT. Most of my above ground is either 2" or 3/4". The 2" is all straight - no bends required. The only exception is right by the service entrance. What I did is transition to EMT right at the ground entry/exit. This picture is right after installation before filling with gravel and installing EMT straps. The 3" schedule 80 PVC is on the bottom left - that is the top of a premade 36" sweep. A schedule 80 SLIP to MIP adapter, and that short run is 3" EMT into the raceway. Coming from the raceway I transitioned down to 2-1/2" EMT (smallest that fits fill requirements) and that is a premade 90 which was under $15 from garvin that connects to the AC disconnect. I spent a lot more on the large rain-tight fittings than the EMT or the pre-made 90. On the far left you can see my 3/4" EMT scrap pile - leftovers or mistakes.

                  https://flic.kr/p/PrJA2N

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