OT: Vacuum to pull thread through conduit...?

[Kenneth]

Howdy,

I have a underground conduit that runs about 340'. Right now, it holds two wires (a networking cable, and a phone cable) but there is no pull cord.

I want to pull a fiber optic cable...

I have been told that with the proper setup one can use a shop vac to pull a thread through the conduit (the thread, in turn, pulling a cord etc.) It was suggested to me that a ping pong ball attached to the thread would do the deed, but there is not sufficient space for the ball to enter the conduit.

(I should add that I could use the network cable as the pull cord, but I would strongly prefer leaving it in place until I have its fiber replacement working.)

Anybody out there know how to approach this hassle?

Thanks for any help,

[Harry Everhart]

I have done this with a piece of crumbled up newspaper. I attach a piece of fishing line to the newspaper crumple ball and suck it through with the shop vac. Once you have the fishing line through - you can gently pull the cable through. Good luck. Harry

[Jamien]

Pull either another phone wire or network cable (whichever is cheaper) along with the fiber optic wire, using either the old phone or network cable. Reconnect the new phone/network cable and then take your time figuring out the fiber optic connection.

Bob's your uncle.

Jamie

Kenneth wrote:

[Roy Smith]

If the conduit was empty, I think you might have a chance of getting a messenger through it with air pressure. But given that you've already got a couple of cables in there, I'd be very surprised if you could get it to work.

[beamer]

i have pulled a string through using a piece of sponge that was cut round but slightly bigger than the conduit internal diameter. The shop vac pulled it just fine.

[Unquestionably Confused]

While I admire the novel approach to your predicament, I suspect that the ping-pong ball and thread (I would use nylon monofiliment fishing line myself) will never work for the simple reason that even if it would fit in the conduit, you have two lines in there now which will 1) act as spacers reducing the already meager vacuum attained in a 300' plus run and 2) they will be twisted about in there and form a "solid" block to any such ball that would fit. The ball might make it some distance but the odds are that you're going to bog down in a number of places.

Frankly, you don't say how big the diameter of the conduit is but here's what I'd do.

Disconnect the phone cable at both ends and use your phone cable to pull through the lead cord to pull BOTH the fiber-optic cable and phone cable back through.

The way I see it you're going to lose either the phone service or network connection to accomplish this. In either event you shouldn't be without the service for much more than an hour.

[Searcher 1]

The last seems to be the MOST reliable idea! At least that way you would still have both options.

Searcher1

[Jeff Kingsley]

A small balloon can be made just the right size to suck through as well.

[Wood Butcher]

This is the most practical response yet.

One addition: Add a second pull cable along with the fiber-optic cable and phone cable. Leave this in the conduit for when you need to pull yet another cable in the future.

Art

While I admire the novel approach to your predicament, I suspect that the ping-pong ball and thread (I would use nylon monofiliment fishing line myself) will never work for the simple reason that even if it would fit in the conduit, you have two lines in there now which will 1) act as spacers reducing the already meager vacuum attained in a 300' plus run and 2) they will be twisted about in there and form a "solid" block to any such ball that would fit. The ball might make it some distance but the odds are that you're going to bog down in a number of places.

Frankly, you don't say how big the diameter of the conduit is but here's what I'd do.

Disconnect the phone cable at both ends and use your phone cable to pull through the lead cord to pull BOTH the fiber-optic cable and phone cable back through.

The way I see it you're going to lose either the phone service or network connection to accomplish this. In either event you shouldn't be without the service for much more than an hour.

[Patriarch]

"Searcher 1" wrote in news:ROrUd.15096 $QQ3.14619@trnddc02:

Pull a new pull cord with the bundle as well.

And the wires you pull should be as 'dense' as you can afford. ie: 12 strands of fiber optic, in one sheath, take insignificantly more space than

2 or 4 strands.

And, if it will fit, pull extra copper as well.

The air-blown fiber is a tested method, but not so effective for in-service retrofits, as I recall.

Thinking about this, if you're doing a lot of this, you will want to do this in a maintenance window. The chance is not trivial that you will mess up the data cable you didn't want to disturb.

Patriarch, who HATES pulling cable in the middle of the night on Saturday...

[Ray V]

I agree, but would also 'grease' the new cables. Soapy water at a minimum if you are worried about degrading the insulation.

[Lew Hodgett]

It's known as a "mouse" by most electrical contractors, but in this application forget it since you already have cable in the conduit.

Buy new 500 ft spools of each cable, a bucket of wire-ez, and a take up winch and have at it, using one of the existing wires to pull the new stuff thru, assuming the conduit is large enough.

May be able to sell off the old stuff for scrap value.

Having been to this movie, suggest you have somebody who has the tools do it.

Even with a strong back, this is not a DIY job.

HTH

Lew

[Korny]

For a mouse that will work alongside the two existing wires, use a ball of cotton. Put a short wire through the middle of the mouse to attach to a nylon pull cord. Put a large flat washer ahead of the mouse to hold the string in place. Start the mouse and hook a good shop vac to the other end of the conduit. The mouse will run through and pull the cord through.

When you pull in the new cable, run a new pull cord with it for future reference.

If you pull new cable, always put a pull cord with it- ALWAYS!.

[Eradicate Sampson]

Try a plug cut from isocyanurate insulation board (aka pink or blue foam)

[Bill Thomas]

Greetings,

I have pulled one cable across another with the result of the pulled cable cutting through the insulation and into the conductor of the other cable.

I suggest you take the advice to use the existing cable to pull a pull line into the conduit and then pull a new set of cables. Also, take the advice to use a lubricant designed for cable pulling.

Good luck. You will need it. Have a plan for what to do if the existing cable breaks before you get the pull line through. You have a very long run, 360 feet. Talk to some people who regularly pull cables this distance. Tell them what you plan to pull and the size of the conduit.

Sincerely, Bill Thomas

[Doug Miller]

Yep, that works. All you need is something lightweight with a reasonable surface area for the vacuum to grab hold of. Here's what has worked for me: tear off about an inch, inch and a half of masking tape, and fold it against itself around the end of a string so it makes a kind of "flag".

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[Russ]

[Mike M]

We use a combination of blowing and sucking all the time. With the distance you have to go I recommend working from both directions. Problem #1 the existing cables, problem #2 most existing conduits in the ground are full of water, at least here in the northwest. You can blow this out if you have enough air pressure. A mouse won't work with existing wires in the pipe. What works well sometimes when nothing else will is a plastic baggie that can conform to different shapes pulling a string made for this. If I was bidding the job thought I would price it on using an existing wire for a pull line. I'd give the pull line a couple of tries then go for the sure thing to keep the labor down. MikeM

[Leon]

Several years ago I watched an electrician run computer cable lines from one building to the next under a parking lot. The run was about 500 feet. He used what looked like a toy parachute tied on to the end of nylon string and then pulled the cable back with the string.

[Larry Jaques]

On Sun, 27 Feb 2005 16:33:07 -0500, the inscrutable Kenneth spake:

I wouldn't try it in anything other than an empty conduit.

Attach the cord to the network cable and pull it through. Now add the fiber cable and pull both through with the cord. You'll be done in an hour with original cable installed as a backup.

When you attach the cord, make sure to taper the tape onto the cable, preventing sharp edges, so it doesn't become an obstacle.

-- "Menja bé, caga fort!"