Pulling MHF through conduit

[gtae07]

Hopefully this weekend I'll be trenching and laying conduit for my power feed from the house (90A subpanel in shop, 2-2-2-4 MHF). I'm looking at right about 100ft of 2" conduit, with two 90deg sweeps plus a gradual 10-15 deg bend over the length. I get that, because the glue can eat the cable's insulation, I have to lay the conduit and pull the cable afterwards; the question is, how do I do that? Yes, use lots of lube and have one guy feeding while the other pulls, but how do I attach to the cable, what do I pull it with, and how much force should I expect it to take?

Also, I assume I use one of these through a vinyl mount block/penetration to transition into the sides of the structure--if not, what should I use?:

 

[kd3pc]

I use a leaf blower to blow twine from one end to the other. Then use that to pull a pulling line back in....anything from small paracord all the way to fractional inch line/rope - depending on how long and how much length line I have on hand.

I use a pulling cuff (think chinese finger cuffs) that I have had for decades. It will take some effort to pull and you should have someone feeding it and pushing at the other end. Soap will help.

The LB you show will likely be fine for the transition

 

[Syberia]

I've never done it with MHF, but I've done it with #8 THWN. I used 3/16" (I think) rope, tied it around the wires in a few places, covered with duct tape to keep it together, pulled from one end while my wife pushed/steadied it from the other. It was surprisingly easier than I would have thought.

If you didn't put a pull rope in the conduit when you put it together, you can attach a shop vac to one end, feed a string through the other, and when it comes out the other side, use the string to pull a heavier rope through that you'll use for pulling the wire.

 

[alfredeneuman]

You could use a fishtape, and avoid the "how to get the rope through" issue altogether.

Strip all the wires about a foot.
Cut all the strands in each wire back to the insulation except for 2 or 3.

(Be sure to stagger the wires a little so that they have a tapered instead of a blunt end.)

Bend the remaining strands except for 1 strand of 1 wire tightly around the eye of the fishtape or rope and pinch it down with a pair of Channellocks.
Use the single strand to tightly wrap the bundle together, so the don't unbend from the eye of the fishtape.

Cut off all bent strands that overlap the insulation to the insulation.

Tape starting ahead of the eye of the fishtape, a gradual taper with electrical tape or ductape, going back to beyond the insulation.

Wrap the entire thing with electrical tape, but double the end of the tape back on itself for about 3/4" so you'll have a little handle to remove the tape.

 

[gtae07]

I'm not worried about getting the string/rope through the conduit; my concern was more about attaching it to the cable, and making sure it won't break halfway through. The fishtape might be useful but I'd rather not buy another single-use tool.

 

[alfredeneuman]

The method that I mentioned for hookup a fishtape will work equally well with a rope.

It's guaranteed to work. I've used it on stranded wires from #14 up to 750 kcmils.

 

[mrolds88]

Alfred has a good idea. Did similar with my feed (3" conduit, 4/0, 4/0, 4/0, 2/0) but used rope1/4 or 3/8 can't remember. That stuff is worse to work with. What you have should go a lot smoother because its more flexible. I also don't see the need for lube. 1 guy pulling and 1 guiding/pushing yes. I would bring your conduit up to breaker box level then run it through the wall into the back of the box. Unless you can situate the sweep for the garage end to where it turns up right under the wall.

 

[alfredeneuman]

1 issue with small pull ropes is that the rope can burn right through the inside radius of PVC 90°s by friction. You can't pull rope either way at the point.
Use as big a rope as you can find.

 

[mrolds88]

You are right. That's why we pulled slow. Used the winch on the 4 wheeler. Slow and controlled.

 

[pattenp]

I've pulled #2 MHF several times through 2" conduit for the distance that you are looking at and never needed any lube. It will pull very easily.

 

[wyliesdiesels]

What i do is put the pull string or rope through the conduit as i glue it. Make sure to pull the rope a little as u glue each stick to make sure the rope isnt glued stuck to the pipe.

 

[soob]

It's rated for direct burial. Just bury it, I say. If you're worried about it getting damaged put the conduit on top of it.

 

[FullRaceMerc]

We use a large shopvac at one end & a lightweight string with a "mouse" fed in from the other end. Then use the string to pull larger pulling rope or muletape because the little string will burn thru the PVC 90s as mentioned above. In turn the pull rope or muletape pulls the wire.

I can't find a pic of the "mice" we use, but they look sort of like a mini hot air balloon. The string ties to a bail at the bottom & the "balloon" feeds into the conduit & is caught by the vacuum. I have seen guys use all sorts of lightweight "mice" fluffballs tied to a string. As long as it travels thru the conduit & doesn't come off the string they seem to work.

Another thought might be to see if your local rental yard has a fish tape for rent.


Muletape. It works great for tying off wire without adding bulk. It's also marked in feet which can come in handy.

By laying the muletape flat thru the knots & taping around it this tying method it works pretty well. For a heavy pull we'll add more knots down further.

 

[Jlarson]

You can easily **** or blow string into 100' of pvc with a piece of shopping bag and shop vac or blowgun. Actually on short runs like that I skip the string and shoot mule tape right in, half hitch it and pull.

 

[UserNameAttempt3]

x2 or x3... Fish Tape or Mule tape... buy some lube too if you are that concerned.

http://www.amazon.com/dp/B0019J8AGC/?tag=atomicindus08-20

 

[gtae07]

Alfred has a good idea. Did similar with my feed (3" conduit, 4/0, 4/0, 4/0, 2/0) but used rope1/4 or 3/8 can't remember. That stuff is worse to work with. What you have should go a lot smoother because its more flexible. I also don't see the need for lube. 1 guy pulling and 1 guiding/pushing yes. I would bring your conduit up to breaker box level then run it through the wall into the back of the box. Unless you can situate the sweep for the garage end to where it turns up right under the wall.

Foundation's already set, but I'll just bring it right up into the back of the panel like you said. It'll make things easier.

It's rated for direct burial. Just bury it, I say. If you're worried about it getting damaged put the conduit on top of it.

The problem is that a good chunk of the run is going to be right under the "driveway" to the shop (no concrete; either gravel or grass with reinforcing mesh). Vehicle access won't be frequent but still, I'd rather have the conduit there. I'm going to lay a small (1/2 or 3/4) line for ethernet on top of it. Also, with the conduit I can lay it in now and then take care of the cable itself later.

Looking at the routing I'm probably going to have to put a 45 in to change direction, and maybe another 10-15 deg sweep further down.

 

[mobiledynamics]

For all you seasoned pros/joes, how do you ~convert~ the size of a blower head (6" or so) to fit snug onto a 2" or less pipe . Lotsa Tape to the nozzle ?

On the rare occasions I've need to get a string into pipe 1st, I've used a regular vack **** method. I'm about to do a run that is about 100-150 feet of 2" pipe.


Or is there some sort of aftermarket solution that is not as expensive as let's say a full blown Greenlee Blower System

 

[Thumper68]

I just tie a bit of plastic bag to a string and **** it through with a sop vac, then use that to pull a larger rope in, I really like the Chinese fingers for pulling.

 

[Aceman]

For all you seasoned pros/joes, how do you ~convert~ the size of a blower head (6" or so) to fit snug onto a 2" or less pipe . Lotsa Tape to the nozzle ?

On the rare occasions I've need to get a string into pipe 1st, I've used a regular vack **** method. I'm about to do a run that is about 100-150 feet of 2" pipe.


Or is there some sort of aftermarket solution that is not as expensive as let's say a full blown Greenlee Blower System

It does not take an expensive blower or vacuum system to get string in pipe.

We did a job for the power company running 5" pvc for 5+ miles with pull vaults every 700'. I was able to use a plain jane Ridgid shop vac to **** in 500lb red string tied to the handles of a walmart shopping bag with another shopping bag wadded up inside it to keep it from collapsing.

So, a 2" conduit 150' long is nothing for a regular shop vac. Off the top of my head, I think the farthest I've shop vac'ed a 2" is 1600'.

 

[mobiledynamics]

I presume it's just more than sticking the hose onto the end of the pipe right ?

Tape it till it makes a seal ?

 

[Aceman]

I presume it's just more than sticking the hose onto the end of the pipe right ?

Tape it till it makes a seal ?

Hold it tight to the end of the pipe is all you need to do. Try it for yourself, you'll see.

When I did the 5" I think all I did was stuff rags in the gap beside the vacuum hose and conduit.

Basically, the suction you feel at the vac hose will be the same suction you feel at the end of the conduit, so if you have good suction there won't be any issues. Make sure your filter is clean.

 

[walrus]

If there is water in the pipe it might not be as easy

 

[mobiledynamics]

If you are working in a older pipe with unknown crud........do you run a 3/8 compressor line through it. Just curious how you pros do in this situation....

And or you're pulling a line and it becomes a bear to pull, even though the drag string went through just fine.

 

[trentonmakes]

I presume it's just more than sticking the hose onto the end of the pipe right ?

Tape it till it makes a seal ?

Nope... That's pretty much it
Just use your hands to seal any gaps... Lightweight string and a plastic bag works great!

Use light string to run your pull string through.... I've tied off to vehicles or forklifts if accessible to pull in tough situations


Sent from my LG-D801 using Tapatalk

 

[Highbeam]

I used a shop vac to pull mason string through. The mason string is strong enough but can cut the conduit if you pull too fast. I just tied a wad of plastic home depot bag to the string and it sucked really really fast. Lay out the string so it has plenty of slack to pull in. It is easy to end up with a shop vac full of string.

 

[Falcon67]

I used 1/4 nylon rope because it was cheap. Tied a wad of paper towns to one end and used the shop vac on the other. Lubed the cable and it slid right through.

 

[Syberia]

For 3/4" conduit the hose of my vacuum fits right over. Anything else and I use duct tape to seal the air gap.

 

[chops101]

I just pulled 152' MHF thru 2" conduit.
I helps if you have a pusher and puller.

 

[My Old Tools]

Dawn dishwashing detergent makes a good emergency lube.

 

[pattenp]

I would not use any thing to lube wire other than lubricant made for pulling wire.

110.11 Deteriorating Agents.
Unless identified for use in the operating environment, no conductors or equipment shall be located in damp or wet locations; where exposed to gases, fumes, vapors, liquids, or other agents that have a deteriorating effect on the conductors or equipment; or where exposed to excessive temperatures.
FPN No. 1: See 300.6 for protection against corrosion.
FPN No. 2: Some cleaning and lubricating compounds can cause severe deterioration of many plastic materials used for insulating and structural applications in equipment.
Equipment identified only as “dry locations,” “Type 1,” or “indoor use only” shall be protected against permanent damage from the weather during building construction.

 

[alfredeneuman]

In addition to the 110.11 issue, dishwashing liquid dries out after time.
That causes the wire to the stick to the conduit and even if you pour water down it, doesn't help much when you go to pull the wire out.

 

[My Old Tools]

Somebody will have to show me a wire damaged by Dawn before I'll believe it.

 

[mobiledynamics]

Why PROMOTE a HIGHLY AKALINE product when there are dedicated LUBES for this

Now if this Simpull, no LUBE would even be needed

 

[damienga15de]

Talcum power works great for lube too.

 

[alfredeneuman]

You wouldn't use wire lube to wash your dishes.
Why use dishwashing liquid as wire lube?

Both products are meant for a specific purpose

 

[404]

Why PROMOTE a HIGHLY AKALINE product when there are dedicated LUBES for this

Now if this Simpull, no LUBE would even be needed

Simpull, for us ignorant folk..
Pretty cool.

 

[wyliesdiesels]

You wouldn't use wire lube to wash your dishes.
Why use dishwashing liquid as wire lube?

Both products are meant for a specific purpose

Simpull, for us ignorant folk..
Pretty cool.

Thats a video marketing their SimPull cable reel.

Heres another link

http://www.southwire.com/commercial/nolube-simpull-thhn-cable-revolutionizes-installations.htm

 

[mobiledynamics]

I love Southwire. It's the only wire I used.
For portable cord however, all I use is Carol

 

[lbmcse]

For all you seasoned pros/joes, how do you ~convert~ the size of a blower head (6" or so) to fit snug onto a 2" or less pipe . Lotsa Tape to the nozzle ?

On the rare occasions I've need to get a string into pipe 1st, I've used a regular vack **** method. I'm about to do a run that is about 100-150 feet of 2" pipe.


Or is there some sort of aftermarket solution that is not as expensive as let's say a full blown Greenlee Blower System

A cut-off top from a 2 liter soda bottle (or Gatorade bottle, or ANY tapered plastic bottle) and duct tape to cushion the seal.