Pulling Wire through conduit- tips ?

[SPIKER]

This post started a while back but I wanted my 2 cents worth in there.

like others said, it is easier to pull the length of wire through a stationary conduit than to try and pull one little bit of conduit all way down and risk getting glue all over the wires when assembling the conduit. wires actually pull pretty easy if done right. especially the thhn/thwn/USE types of wires. mtw is harder and is not really meant for service anyway. "U.S.E." (underground service entrance) can be direct burial wire & type THHW/THHN are meant for in conduit for this type of application the THHW/THHN have an outside jacket of slippery material (Teflon/Nylon like coating) which helps it pull much easier. the type U.S.E. also has the coating but a little thicker jacket meant for direct burying.

Pulling lube ONLY in any type of conduit, ya lots of stuff can be used but type #77 or T & B also has some which is only slightly more cost than dish soap and is 100% non-effecting the wire jacket.


it is best to assemble the conduit into the flat bottom trench count up the # of sticks you have and add a few feet, remember they are 10' lengths, if ya cut one in half count it as a hole length. a few extra feet of wire is cheap compared to pulling the short length out and replacing it. not to mention you can take it to the scrap yard and get back some $ for the copper scrap.

ONLY use straight runs and sweeps at ends coming in and out, if you have to have bends in there some place be sure to take a running count of the total # of degrees of bends, never have more than 360 degrees of bends in any single run a pull box is required at or before 360 degrees of turns. there are also max distances of run prior to needing a pull box. I like to ave more boxes just in case, but at least every hundred feet unless you are making one single run from building to building or to a pole. then you can stretch that distance out but beware local codes & elec companies may want pull boxes more or less at shorter distances. make sure to check this out prior to buying anything.!

Shop vac and or compressed air with kite string and a plastic bag/mouse works well for getting string started through the conduit then pull in a rope and use the rope to pull in the wires. keep a few extra feet on each end which can be cut off easily adding it back is a lot harder having the conduit stationary in the ground makes pulling a LOT easier than attempting to pull wires into it then bury it as the conduit will move about a lot... something that makes it darn near impossible to do a long run with and assembling it in the trench can get a lot of dirt into conduit and glue onto wires ... adding an extra 3 wire set of 12 gauge for lights on/off is also a great idea!

my 2 cents worth,

markM

mark M

have fun

 

[8NTX]

I did a 650' pull with 3-#4's and 1-#6 wire a couple of years ago and got lots of good tips here. One piece of advice that stuck - do NOT use liquid soap for the pull; only use wire lube. Something about the soap possibly doing damage to the wire over the years. I buried the conduit first, but what Eddie said makes sense for 125 ft.

 

[boyah]

hi,
Im trying to replace some wires for my A/C. The wires run under my slab to the circuit breaker box about 40 feet. I disconnected everything so all I have left is the wires and I cant get them to budge. There is one pull box but it is right under the circuit breaker box. Does anyone have any ideas on how to replace these wires. I wanted to just attach a new set of wires to the old ones and pull them through. I have to replace the wires becuase water got into the pipe and ruined the wires. What are the tricks of the trade?
Thanks

 

[Illini22]

when I pull wire usually 4/0 phases 2/0 nuetral I always put a ladder above the pipe I'm pulling from and hang a pulley,dolly, wheel or whatever you may call it and put rope thru dolly and pulldown. Sometimes making a loop in rope (twisst it a couple of times and hold knot with hand) and stand on loop, comes thru nice without braking your back or cutting rope on side of pipe, as long AS PULLEY IS RIGHT ABOVE PIPE.

 

[ray66v]

You're only going 125 feet. Is the pipe already in the ground and buried?

If it was me, I'd unroll the wire along the trench, then slide the pipe over it and glue together. It's simple to slide the pipe over the wire and with only 13 pieces to deal with, it will take you less than an hour.

Don't make it complicated when you can do it easy.

Good luck,
Eddie

I agree.

 

[Treemonkey1000]

I worked at a cable shop where we built large and small cables. From 2' long to 300' long. Wires that were 1/4" thick up to about 1.5". We had a machine that blew compressed air through the correct size nozzle. Inside of that nozzle was what we called the "mouse" it was a steel slug with a winch cable attached to it. We would shoot the compressed air down the tube that dragged the winch cable behind it. Before we shot the mouse we put talcum powder in the tube to reduce friction. Once the mouse reached the end of the tube we connected our cable to it. Then winched the cable back down thru the tube. It worked slick. So what my point is if you want either blow a string down with compressed air or try to suck it down with the vacuum. Use talcum for reducing friction. I don't believe you would need to use a winch to pull the cable thru. That might break the pipe if you weren't careful.
Jim

 

[swampvol]

125ft?
For the cost of the rope that you're pulling through it , just by a Greenlee 250' fish tape. You can easily push the tape through the conduit, as long as you have the couplings snug, then just loop the wire to the end of the fish tape, wrap it with electrical tape, put a little yellow 77 on, and pull...

 

[Bill Barrett]

This post started a while back but I wanted my 2 cents worth in there.

like others said, it is easier to pull the length of wire through a stationary conduit than to try and pull one little bit of conduit all way down and risk getting glue all over the wires when assembling the conduit. wires actually pull pretty easy if done right. especially the thhn/thwn/USE types of wires. mtw is harder and is not really meant for service anyway. "U.S.E." (underground service entrance) can be direct burial wire & type THHW/THHN are meant for in conduit for this type of application the THHW/THHN have an outside jacket of slippery material (Teflon/Nylon like coating) which helps it pull much easier. the type U.S.E. also has the coating but a little thicker jacket meant for direct burying.

Pulling lube ONLY in any type of conduit, ya lots of stuff can be used but type #77 or T & B also has some which is only slightly more cost than dish soap and is 100% non-effecting the wire jacket.


it is best to assemble the conduit into the flat bottom trench count up the # of sticks you have and add a few feet, remember they are 10' lengths, if ya cut one in half count it as a hole length. a few extra feet of wire is cheap compared to pulling the short length out and replacing it. not to mention you can take it to the scrap yard and get back some $ for the copper scrap.

ONLY use straight runs and sweeps at ends coming in and out, if you have to have bends in there some place be sure to take a running count of the total # of degrees of bends, never have more than 360 degrees of bends in any single run a pull box is required at or before 360 degrees of turns. there are also max distances of run prior to needing a pull box. I like to ave more boxes just in case, but at least every hundred feet unless you are making one single run from building to building or to a pole. then you can stretch that distance out but beware local codes & elec companies may want pull boxes more or less at shorter distances. make sure to check this out prior to buying anything.!

Shop vac and or compressed air with kite string and a plastic bag/mouse works well for getting string started through the conduit then pull in a rope and use the rope to pull in the wires. keep a few extra feet on each end which can be cut off easily adding it back is a lot harder having the conduit stationary in the ground makes pulling a LOT easier than attempting to pull wires into it then bury it as the conduit will move about a lot... something that makes it darn near impossible to do a long run with and assembling it in the trench can get a lot of dirt into conduit and glue onto wires ... adding an extra 3 wire set of 12 gauge for lights on/off is also a great idea!

my 2 cents worth,

markM

mark M

have fun

I think this guy has pulled some wire.

Back in the day, I use to pull 500 MCM all the time. We used lots of lube, pulleys, aircraft cable, and a forktruck, piece of cake.

 

[keeney]

I think by code, you are required to assemble the conduit and then pull the wire. Part of the idea of the limited length, limited number of corners, and frequent pull boxes is so that the wire can be replaced or upgraded someday if necessary without digging everything up.

If you assemble the conduit around the wire, you may find that you can never pull the wire back out for replacement due to too many turns, too much wire packed in that you would never be able to pull out through the whole length, kinks and tangles, or the glue sticking to the wire or something.

As the old saying goes - most mechanical problems are easily solved by applying a little more force or a little more lubrication.

In this case, go with the lubrication. It makes a world of difference. Also, make sure the wire is layed out kink-free and tangle-free and not dragging too much dirt into the conduit with it.

If working alone, squirt a bunch of lube into the in-going side of the conduit so the wire gets pulled through a healthy blob of the stuff. Then run to the other end, pull a few dozen feet, run back and add some more lube, repeat.

Always use the purpose-formulated stuff like the Ideal #77. Using anything else could weaken the wire jacketing or the conduit, or cause corrosion in a metal conduit. Even baby powder has some solvent and perfume in it that can degrade some plastics over time.

- Rick

 

[Superduper]

(1) Fish tape is easier than using rope.
(2) DO NOT use grease.
(3) DO lubricate the cables; having helper to assist feeding and lubricating [with approved cable/conduit lubricant ONLY] will make job easier.
(4) 2" conduit is plenty big. Up to 14 #4 cables may be used although in practice, that is almost impossible to pull that many.
(5) #6 ground should be all you will need.
(6) MAX 360 degree combined bends. More will require pull bodies or junction boxes.
(7) Pull bodies and box access covers MUST BE accessible.
(8) Stranded cables will be MUCH easier to pull than solid cables.