What's new
What's new

Pulling wires in conduit

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
I need to pull some big wires to run power to my shop. I will be pulling three #2 amd one #4. I have neve rpulled anything bigger then #10 before so I have a question. Should I try to pull all these wires in one shot or pull one at a time. I am using 1 1/4" pvc conduit with few bends.
Bill D.

Also how to attach the pulling rope
 
Easiest to pull all at once. Skin the insulation off of each wire about 6" long, and cut off all but 2 strands on each wire. Bend the strands over onto the rope eye in sort of a hairpin shape. Make the 'head" as small as possible to fit thru bends easier. Squeeze them tight together with a pliers, and tape up with electrical tape, or some duct tape. Use some dish detergent for lubricant. Good luck on your project! Joe
 
I think you want to pull all at once or you will end up with the pull cord and subsiquent wires wrapping around the wire that you pulled first and then it will all get stuck. Using pulling lubricant also helps.

Jeff
 
you have to pull all at the same time or you stand a chance of wearing a hole in the wire you have already pulled. Get some pull lube and glob it on and you should have no problem.
 
You absolutely want to pull ALL the wires in one shot. Too much risk of damaging insulation with multiple pulls.

As far as attaching the conductors to your pulling rope, what you REALLY want is a "pulling grip" made for the purpose. Essentially, a wire mesh tubular basket that works like one of those Chinese finger trap toys. Slips down over the wire bundle, and once installed, the harder you pull, the tighter it grabs the wires. It has a wire loop at the end to attach to the rope. Here's some examplea:

http://www.mytoolstore.com/klein/kln34.html

If you don't want to buy a pulling grip, get yourself a BIG screw-on lug large enough to accept ALL the conductors, and attach it to the end of the bundle after stripping the ends. Use the bolthole to attach to the rope. Tape the lug up well to smooth over any sharp corners which might snag during the run.

Use a LOT of wire pulling lube, and have a helper pushing the wire into the conduit (and slapping on the lube) while you pull on the rope at the other end.
 
As long as your bends do not exceed 360' you should have no problem

Remember - the pulling lube is for the integrity of the wires, not for you. You can pick up some "Yellow 77" at Home dippo right next to the wire
 
If you don't have a fish tape long enough - Tie a piece of paper towel (maybe 3" x 3") to the end of the string and use a shop vac to blow it through the conduit. Use the string to pull a heavier cord. Pull all cables at the same time. Stagger the ends so you don't have a big knot at the end. I just lay the cord along the first cable, elec tape it for several inches, pull it back to the end, wrap again. Then tape the other cables to it. Too much taping is about right.

Cable grease will help. So will keeping the cable very clean as it goes in (ever throw sand under tires in the winter, same concept). Hopefully all the conduit is glued up so the cable goes into each piece on the bell mouthed end. Otherwise you risk getting the edge of the cut cable hung up on the lip of the pipe.

Steve.
 
Another lubricant - if its dry pipe (i'd hope so) - the miss's talc (if you don't mind the smell).

Not as messy as cable grease or washing liquid.

Don't attempt to pull cable through more than 2 No. 90 deg. solid bends.

Mark
 
All the above. All at once, pulling grip, Yellow 77 and add a pull rope to the bundle for possible future use.

Should you ever need to pull in anything else, you'll find out why you pull it all at once but you could get lucky.


I suck the pull string through, in 1-1/4", I'd cut an 8" corner out of a plastic shopping bag and poke the string through 2 sides of the plastic. When you apply the vacuum, it will expand to fill the pipe and shoot through.

Blowing means feeding air and string at the same place, a little awkward.

Commercial electricians use a dedicated winch for tough pulls. 3-#2 and 1- #4 might put up a fight, if needed, you can make a come-along work, taking repeated grabs on the pull rope 'til it's pulled. Have someone whose handy, to keep the conductors straight for feeding and make sure you can communicate.

Have fun, Bob
 
Bill, 1 1/4" conduit is about maxed out for your pull. If the pull is straight with 90 degrees worth of bend it should not be too bad. If the pull is fairly long and you start adding bends you may want to think of adding an LB. Your wire is stiff and even with pulling slime will be a bit of work. It will also be helpful to have another person on the spool end pushing as it is being pulled. If you bumped your conduit size up even one size the pull will be noticably easier.

You mentioned three #2's and one #4 for conductors. I'm assuming that the #4 is for ground. If this is the case let me encourage you to think of running your ground as at least a #2. 20 years ago it was common to undersize the ground but with todays equipment and electronics it is starting to be common practice to run the ground the same size or even oversized.

Luke
 
Is the conduit already glued up and in place? If not slide the conduit and fittings over the wire and then glue them up.

I ran underground conduit to my shop using this method.Saves a lot of pullin'
Might make things easy, but it is also a violation of the NEC. The code specifically requires that all conduits/raceways be installed COMPLETELY before pulling wires.

If you don't want to do this, then you should have used direct burial cable, and saved the work of installing conduit in the first place. If you couldn't install the wire originally and had to cheat, how the hell is anyone supposed to ever be able to REPULL the run at a later date?
 
If you do that you have to be REALLY careful to not get glue on the cables while still getting enough to seal the conduit.

Steve.
 
Might make things easy, but it is also a violation of the NEC. The code specifically requires that all conduits/raceways be installed COMPLETELY before pulling wires.

If you don't want to do this, then you should have used direct burial cable, and saved the work of installing conduit in the first place. If you couldn't install the wire originally and had to cheat, how the hell is anyone supposed to ever be able to REPULL the run at a later date?
Well this wasn't by NEC specs. I already had the wire so I dind't want to buy underground wire.

I will edit my past post, seems like I am giving some very bad advice. Many times I have been told I know just enough to be dangerous....
 
Hmmmm....

I think Luke is right.... that conduit is small for the wire. It better not bhave very many bends at all, or be pretty short.

I've pulled large wire before, and it was no picnic. of course I was pulling 3/0, but on a short pull. It was tough work.

The distance kind of trades off with bends. Distance adds resistance to pulling, and so do bends. Long distances need few bends, or you will want an adequately sized box at "corners".

Distance also wears off your pull lube, so it gets harder to pull, and no good way to get more in tehre if it gets tight.

if you have any way to do it, do bigger.
 
Blowing means feeding air and string at the same place, a little awkward.
Depends on if you are working alone. I found it's much more awkward to go to the other end of the pipe to find out why the f*&^(&g string is stuck again!


Steve.
 
1-1/4" PVC can carry up to 4 #2 THWN wires, so 3x#2 and a #4 is close to the limit, but legal.

Unless you have a very short run, it is going to make pulling a lot harder than if you used a 2" or even 1-1/2" pipe. I try never to be anywhere near the capacity limit for a conduit if I can at all avoid it.

When assembling long conduit runs that I will be pulling within a day or 2, I squirt a glob of wire lube into each conduit length as it gets installed. That way, there is plenty of lube along the entire length when pulling. ONLY do this if you will be pulling within a couple days, because if the stuff dries out in the pipe, it will make the pull a real PITA.
 
SIR,
your job would go much better if you used
2in. conduit. push the tape through the
pipe, and tie onto a nylon rope, then pull
with the rope. you do not say how many 90
degree turns you have. four will be the max.
and as the other post have said, use a
pulling lube, not detergent.
good luck.
wlbrown
 
Allow approx 50% spacing factor.
ie. Overall cable csa should not exceed 50% of conduit csa.
This is to allow for heating factors of the cable.

Mark
 
Don't know about the Elec Code in Ireland but in the USA the max cable fill (measured by cross sectional area) is 53% for 1 conductor, 31% for 2 and if over 2 (as in this case) the total conductor csa must not exceed 40%.

Steve.
 








 
Back
Top