Pulling Wire through conduit- tips ?

[MikeA57]

You can never have too much Monkey ***!!!!

(Least, that's what we called it!)

 

[MikeA57]

Seriously though, I once had a job going around the country installing CCTV systems at RR yards that unloaded automobiles onto HUGE parking lots. We pulled MILES of fiber optic and coax cable sometimes hundreds of feet through conduit (and aerially too). Fortunately, our contract stated that the conduit would already be assembled and buried with pull boxes at whatever distance was code for the locale we were working. But some of those pulls were absolute boogers!!! We bought IDEAL 77 in 5 gal buckets and used the snot out of it.

When we arrived on site there would be a pull string in the conduit. We would attach our 3K# rope to the string then pull that through. The rope would attach to a wire mesh collar about 3' long that we had and it would be taped tightly around the cables. We used a LOT of electrical tape and taped well past the mesh collar usually taping 3 layers down away from the head back up to the head and back down. If we had several cables they would be staggered in the bunch to make a smaller head. One guy at the feed end, and one at the pull box or exit end and we'd start to pull. Some of our pulls were so tight that we would have to attach the rope to the hitch of our Toyota pickup and pull with that. Scared us to death that we were going to break the cable the first few times we did that but we never broke a cable and every install worked perfectly.

On a couple of sites we got there and there wasn't a string and we used a small shop vac we carried with a foam mouse to pull the string through. Worked like a charm...

 

[JerryK]

Lowes sells 'Ideal' pulling compound, don't cost much... It is a yellow soapy compound that dries fairly quickly and does not damage the pipe or wire insulation. We used to use 1000' rolls of about 1/16" nylon cord. We used a 'mouse', which was just a piece of foam rubber with a short piece of string tied to it, and we tied this to the end of the long cord. The mouse was cut [after it was first tied] to loosely fit in the pipe. Had different sizes for different pipe. Real HIGH tech. Even a loose fitting vacuum on the far end will zap that mouse thru the pipe real fast. The cord is also handy for other stuff. Tie a tennis ball on the end of it and toss it across your barn, and you can pull a bigger safety line across your barn roof..... Layout work, etc....

 

[flusher]

Came across this thread as I am preparing to build a home and need to get power back to my site which is about 800' back. The power company said I am responsible for the trench and conduit (4" Sched 40 with a 36" radius to 90 degree at each end) and they will pull the wire.

I have not yet asked them this question, but when I assemble the conduit, I assume I have to feed some type of rope or something in it so that they can pull, but what can I use that would stand up to an 800' pull of 200amp service wire?
Should I bury the conduit in spots so that is does not move while they are pulling?
Any advice would be appreciated.

Here's how my electric service (220V, 200 amps) was installed. The trench is about 350 ft long. Conduit is 3" diameter. Two 4/0 and one 2/0 cable. They sent a thin nylon rope down the pipe using a shop vacuum and a plastic bag tied to the lead end. Then they pulled a much larger nylon rope through the pipe and attached it to the ends of the three electrical cables. A winch on the other end pulled the cables through the pipe with the help of a lot of yellow grease. Whole cable pulling job took about 90 minutes.

 

[rd_macgregor]

I wonder if it would work to use a deep-sea fishing reel as a source for blowing in a line to get the pull rope?
BOB

 

[JerryK]

I wonder if it would work to use a deep-sea fishing reel as a source for blowing in a line to get the pull rope?
BOB

Any 'line' will work, as long as it is reasonably strong enough to pull the rope or cable thru. We used to have 100' metal fish tapes, and there was usually a 250' around. But after you spooled that back up a few times you quickly learned to use a mouse. Some cable sheathing [covering] is harder to pull in than others, that is why we used pulling compound. Just a little phone line thru a couple bends can be a pain sometimes.... or some shielded cables.

Here is an old bottle I have left over. Was $5.98 when I bought it about five years ago.. worth every penny IF you need it...

 

[caver]

They make prefab mouse and twine gadgets.

Thin piston on one end with a twine spool that unravels from the inside out.
Before you start your tied end of wire into the conduit dump copious amounts of wire lube in the pipe.
We would pull 3-750MCM HV wires and have one person just dumping handfuls down in the pipe and on the wire.

 

[sparc]

Hi
Ideal Yellow 77 wire pulling lube is the best way to make pulling wire easy.

Charlie.

exactly, why use soap or talc when you can get something engineered to be friendly to the wire jacket is available and not expensive. In a pinch yes maybe you reach for the dawn dish soap but a quart of Ideal Yellow 77 wire pulling lube is like 6 or 7 bucks. I have never tried threading wire or cable through individual pieces of conduit before gluing them together but I don't think I would even consider it for more than two sections, its just not worth the risk of the glue attacking the cable jacket or wire insulation to me.

 

[ericher69]

Instead of using pieces of conduit with joints why not use black polypropylene pipe? It is ok in Ontario and you do not have to worry about glue or making it around corners as all bends are gradual.

Only downside is excavating a slightly wider trench to allow this.

Did this 8 years ago when the electrical inspector wanted me to change the wire out to my shop (was not exterior wire;was installed by prior owner probably without a permit)

Used the winch on the atv for the last 6 feet of pull with no issues.

 

[Qapla]

Depending on the length of the run, PVC glued together BEFORE it is put in the ditch will "bow" far more then you would think - even 2" pipe will "curve" so you do not need to use 90's unless you need to turn in a short distance. When you do need a sharper turn, use a "long sweep" when you can or heat the PVC and bend the sweep yourself.

Also, if you can get it, and you are using PVC, use pipe with bells. It will cut down on the number of couplings you need and you would want to install them in the direction you plan to pull.

If you do need to use a machine to pull the wires, make sure you do not pull them too fast ans they can build friction heat during the pull and the faster you pull the hotter they get since they don't get to cool off during the pull.

 

[Iowachild]

Depending on the length of the run, PVC glued together BEFORE it is put in the ditch will "bow" far more then you would think - even 2" pipe will "curve" so you do not need to use 90's unless you need to turn in a short distance. When you do need a sharper turn, use a "long sweep" when you can or heat the PVC and bend the sweep yourself.

Also, if you can get it, and you are using PVC, use pipe with bells. It will cut down on the number of couplings you need and you would want to install them in the direction you plan to pull.

Anyone that thinks 2" PVC will not bend and bow has never seen a side-boom running 6" or even larger steel pipe into a ditch.

I have never bought PVC conduit that did not have a bell on one end. But than I have only ever bought Carlon brand.

 

[boutym]

exactly, why use soap or talc when you can get something engineered to be friendly to the wire jacket is available and not expensive. In a pinch yes maybe you reach for the dawn dish soap but a quart of Ideal Yellow 77 wire pulling lube is like 6 or 7 bucks. I have never tried threading wire or cable through individual pieces of conduit before gluing them together but I don't think I would even consider it for more than two sections, its just not worth the risk of the glue attacking the cable jacket or wire insulation to me.

I ran wire though individual pieces and glued them after the fact once... Once. Will never do it again. I thought it would be easier than one long run, but it turned out to be more hassle than it was worth.

 

[orezok]

I would highly recommend against pulling wire with any kind of winch or motorized device unless it has the proper gauges for determining pull. A commercial wire puller has an amp meter which determines how much pull is being exerted.

If the pull exceeds the wire's strength it will stretch. What occurs is that a 10ga wire might be stretched at some point into a 14ga wire. This is a recipe for future failure.

When I catch a contractor doing this on my projects, I make them megger the line and many times it fails and they end up replacing the wire at their expense.

Think about a bungee and as you pull it it gets smaller in diameter but longer.

 

[hr3]

I would highly recommend against pulling wire with any kind of winch or motorized device unless it has the proper gauges for determining pull. A commercial wire puller has an amp meter which determines how much pull is being exerted.

If the pull exceeds the wire's strength it will stretch. What occurs is that a 10ga wire might be stretched at some point into a 14ga wire. This is a recipe for future failure.

When I catch a contractor doing this on my projects, I make them megger the line and many times it fails and they end up replacing the wire at their expense.

Think about a bungee and as you pull it it gets smaller in diameter but longer.

How does an amp meter determine that your pulling #10 wire or 500 mcm ??? And another thought,, a megger is only used to check the value of the insulation on the wire not that the copper wire itself is deformed ???

 

[orezok]

How does an amp meter determine that your pulling #10 wire or 500 mcm ??? And another thought,, a megger is only used to check the value of the insulation on the wire not that the copper wire itself is deformed ???

The operator consults the proper table which determines the correct amperage for each type/number of wires.

When the wire is stretch so is the insulation which will be thinner and possible cracked/broken.