How to get untangled runs of wire through a pull box?
- Thread starter Jon456
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Looks like they let them go in the pipe that way when pulling.How does one get untangled runs of wire through a pull box like this?
That's four sets of (4) 500 MCM aluminum feeders. Is there a "trick-of-the-trade" to preventing the wire sets from getting twisted, looped, tangled, and/or birds-nested?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Must be twisted wires to reduce EMI.
I'm not sure what you mean. To me, the above installation looks pretty "clean": all the wires in each set are fairly tight (almost looks like each set is bundled), with smooth sweeping bends and no loops.
In contrast, this is what the same box looks like after a different installer pulled out those wires and pulled in a whole new set of feeders:
I see what you mean now, in this picture, what should have been is each wire at the end of the pull should have been pulled one at a time, just like when you are finishing off an LB so it's nice and neat and UN crossed.
I didn't think that was possible because the individual pull lines seem to invariably get crossed over each other within the conduit. I've only seen wires pulled into conduit as a complete set.
Am I wrong?
K8MHZ
Senior Member
- Occupation
- Electrician
He doesn't mean do the entire pull one wire at a time. What he means is to tug on each one, one at a time, after they are all pulled in. That makes them come out even and not all goofy looking.
K8MHZ
Senior Member
- Occupation
- Electrician
That is the same for both pulls. The first guy took the time and extra effort to do a clean installation and the most recent did the fastest, cheapest installation.
I see. But how does one eliminate loops in the wire (like the wires in the center with the red tape on them)? Just pull them hard enough to change the loop into a spiral twist?
Fulthrotl
~Autocorrect is My Worst Enema.~
- Occupation
- E
couple things. use a swivel when pulling, so you don't spiral them.
if you can fit it in the enclosure, a small greenlee pulling wheel is
the ticket. you can pull in one continuous pull.
if you have to work it in in sections, pull the longest leg first,
stretch out the conductors, and put a turn of tape every arm
length, then **remove*** each tape loop as you pull in the
the other direction. if you tape them up evenly, it'll turn out
nice.
if you don't, it'll look like photo two.
Think of it like this, You feed them in the pipe making sure they do not get crossed up.
When you have all the slack at the box stretch them out and make sure they're not crossed up, now feed them in the pipe on the second half of the pull, when there is 3-5 feet left in the loop, have the guys pull one at a time using radios if you are not within earshot.
- Location
- Simi Valley, CA
I think now that it's done you can't really fix it without a lot of extra effort. I guess if you don't mind killing the power you could do it but why bother. It's just like when guys do panels and pull the wire all the way from the top to the bottom and then back up to the top. I've always been told that it's done so you could relocate breakers if you need too, but how often do you ever relocate a breaker?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
And I always thought the extra wire was to limit the incident fault current. 
Tapatalk!
Tapatalk!
K8MHZ
Senior Member
- Occupation
- Electrician
I think that would be tough with 160 - 200 feet of 500's.
Agreed. In fact, I'd say it would be virtually impossible to fix them without pulling them out of at least one side and starting over.
Coincidentally, we have to completely start over with at least four of the five runs: the installer damaged the insulation on many of those feeders. One whole conduit shorted out -- one set of (8) 500 MCM aluminum wires blew apart -- and three of the remaining four conduits contain one or more damaged conductors based on a megger test and visual inspection. Even the one "good" set may not actually be good because the section of conduit between the pull box and the MSG is dry, so the megger may not have registered a fault. We still need to perform a wet test on that section of conduit.
We've already removed the aluminum feeders that catastrophically failed (they were the ones marked with red tape in the earlier photo). All these feeders have been in service for 18 months. Here are some photos for your viewing pleasure. :roll:
Yes it sure would, but what is a better way?
mike7330
Senior Member
- Location
- North America
You need to use a swivel on the head. As the rope is pulled it will twist the wires in the pipe!
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K8MHZ
Senior Member
- Occupation
- Electrician
Not a better way, but sometimes the only way is to do a really big loop.
captainwireman
Senior Member
- Location
- USA, mostly.
Avoid using twisted rope if you may be thinking about it. You only want to use double braided poly. This is a big safety feature as triplex twisted rope will not only tend to untwist as stress is imposed on it, hence the wires take up this torque and get twisted, but double braid poly has a very low stretch so if the rope or head fails, you will not have a whip-back that could seriously injure anyone in the line of fire. Even still, the swivel is something I would always use. Set up the reels and maintain even pulling stress on the reels by lubricating the axles and having enough manpower to control the feed. Some beefy tie wraps makes for a nice finish if you get them even enough.
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