OK, I'm sure we've all used some method to suck (or blow) a pull-string through a conduit run. I'd like to discuss that: what has worked best for you?

First, do you prefer to use a vacuum to pull the string towards you, or would you rather push it through the line?

If you use a vacuum, which one? Big or small? How have you modified it? What would be the 'ideal' vacuum to have on hand? (Or, should I ask, "two vacuums?")

How do you connect it to the conduit- especially when the pipe is behind a mud ring, off to the side?

Do you make it a practice to tape / caulk / or otherwise seal pipe connections in long runs?

I like that 3M "toner" vacuum. It is compact with a real good motor. There is enough taper in the hose to fit a lot of holes in the 1-1.5 range and if you have some transition fittings in the box you can get to just about anything.

Would that be the #m #497 HEPA vac? At about $250, price isn't impossible. Shoulder strap and toolbox shape (with internal storage) look like good ideas.

It does not look like you can use it to blow, though.

I have always pulled the mouse. It is hard to get a fitting on the pipe that will still let the string through.
If you are sucking from the far end, you just feed the string and listen for the mouse to go into the filter.

It depends on the compressor, but 100 psi from an industrial system with a big hose can't be beat by a vacuum.

Greenlee blower/vac system, older version of the current 690. Backup/helper was a Craftsman shop vac.

Push or vac? Sometimes both, most were a mouse and push, occasional 'pull' from the 'backup vac.

Didn't worry about sealing; all was UG PVC.

EMT, and RGC, was 90% fish tape/snake.

Jet Line makes a CO2 blowing system.
It has a rubber cone (that goes in the end of the conduit) attached to a hose with a hole in it to feed the string through.
The hose attaches on the other to a high pressure CO2 tank.
It doesn't use electricity and can be used anywhere

It works like a charm.

Sure sounds like it beats having a genset, etc. to drag around.

I wonder if it was 'around' before 2002??

If you're talking about the CO2 system, I used a well worn one in the mid '70s.

I guess JetLine is now a Gardner Bender product

http://www.gardnerbender.com/en/jo25

CO2 has become pretty expensive stuff. Maybe a tank of compressed air might be a better choice.

Well, let's see ....

First site I found offers the CO2 system for $1725.50. Another site offers the Greenlee vacuum system for $1435.39.

Both systems seem rather large- one comes on a hand truck, while the other looks to have at least a 12-gallon tank. You're not going to carry either up a ladder, or even fit into your JoBox. I really look forward to dragging either through the 100-yards of mud that seems to surround every jobsite.

I'm sorry, but $1500 is a heck of a lot for a vacuum that isn't even HEPA certified! Just what can this golden calf do that can't be done with a $21 vacuum cover on an old mud bucket?

I've never seen either in the kit of any contractor, even the Union guys doing only heavy industrial work. I can't imaging putting out that sort of investment when your typical "big" pull might be 170-ft. of 3/4" pipe.

Likewise, the plant compressed air solution is nice- IF the place is built and operating. I haven't worked on such a site for ages. I'm usually pulling wire well before the site is even closed in, secure, and conditioned. After all .... which comes first, the air conditioning or the wires?

Someone mentioned underground pulls. Oddly enough, those seem to have the most trouble. Lines fill with water and dirt. Joints are broken, kinked, or crushed by the other trades as the concrete is poured.

This site has thousands of members and we've done millions of pulls. I'd expect a little more response

Electure:

Yes, I was talking the CO2. I never came across one, or saw anyone with one.

Thanks for that.

Reno:

Yes, I mentioned most of the jobs I did were underground. Services, site lighting, sports lighting, etc.

It was unusual to have any issues with the UG PVC, as most jobs were with the same 'other guys'; we all had a work ethic and respect for the job as a whole.

Yes, a vac system was not cheap, I think it was $1k or less back in the day. The Craftsman was about $125 and it did a lot of jobs.

Equipment, like a power bender, puller kit, hydraulic punch kits, etc. IMHO were necessary investments. It also saved the hassle of rental equipment, as rental guys were few.

Heck, now some of the newer guys have battery tools that cost around what you quoted for the vac kit.

Reno:

There was no such thing as a $21 shopvac in the '70s and we were working hundreds of feet away from the nearest power source with no truck access.

You have never seen any contractor that owned such equipment, yet every one of the contractors I've worked for had professional grade tools like that.
They just can't afford the liability involved with sending out Mickey Mouse homemade or Harbor Freight quality setup, besides, they just won't last.


The "typical big pull" isn't 170' of 3/4" conduit, which could just as easily be accomplished with a fishtape.

I was successful in blowing the dirt and water out of a 200' run of 1.25 RNC using a gadget I originally made for an air cannon. I brazed a 3/4" NPT nipple into a freon jug and screwed a ball valve on it. For the cannon, it was capable of sending an orange out of sight but when I turned this over to blowing out the RNC it worked great. I put about 100 PSI of air in it, hooked it to the RNC and let it fly. Dirt, water and mist went about 50' but the pipe was cleaned out. It worked so well I filled the pipe up with fresh water and "shot" it again. just to get the last of the sand out.
Then I blew some soap in there and the wires just sailed through.

I just have to love some of the skepticism I see expressed ... it's almost like someone is thinking "This Reno guy really hasn't a clue about REAL electrical work."

I can only speak to my experience and observations. For all I know, the folks in Amish country use trained ferrets

It's easy to sneer... 3/4? 170-ft? Golly, one time we did something a lot longer and a lot fatter. Sure you did - and for every such pull, you did hundreds of nice, short runs.

Fish tape? Yea, right. A fish has it's uses; I have several. Sometimes they work, sometimes they don't - and most fish tapes are less than 100 ft. long (especially after some years of use). Especially on underground runs, there can be a real problem with the tape hitting a hard stop at the far-away last 90. Hence, the vacuum.

Liability? Huh? Please elaborate, with complete case citation, where it was successfully argued that someone committed a 'wrong' because they used a $25 Wal-Mart vac and taped a water bottle to the hose as a reducer to the pipe. Gawd, everyone's a lawyer these days. I sure hope OSHA doesn't come after me for replacing my old bootlaces with bits of paracord.

Freon? Now the truth comes out, we know WHO destroyed the ozone layer

In happier news, when I told the boss "we" were ready to pull today, he replied "We? Do you have a mouse in your pocket?" I was able to honestly say "why, yes I do!"

Also, as of today, my $21 out-performs the company 'big' shop-vac for this task. I believe this is largely because the impeller on my new vac has not been abraded by dust passing over it- years back I did some propeller testing, and it's amazing how even an invisibly small amount of wear to the blade edge totally killed the performance.

I note that Greenlee sells a much smaller vac, for "only" several hundreds of dollars. Looking to their accessories, I see one they sell for about $30, that I can readily assemble from an $8 set of "car detailing" accessories and a minor amount of tape. Their accessory for blowing line looks nice, but with a price in the three figures, it's no surprise I've never even seen it at the parts house.

IMO, the hard part is connecting the vac hose to the conduit, especially when there are access issues. On this current job, we've had some good results with tiny 1-gallon, 1-hp vacs .... making me again wonder why I haven't seen such an electrician-focused set-up offered for something like $75.

We can't let "best" become the enemy of "good enough." I still wonder at the critics of my tiny bandsaw, because it can't cut 2" pipe, etc. Milwaukee is crying all the way to the bank over that 'inadequate' product!

You said a "typical large pull" not a typical pull.


As to liability issue. I think you're going a bit overboard, and I can think of no case exactly like that ... but you already knew that.
You mad, bro?

I did though, see another contractor's employee using a homemade wire pulling contraption with a drill motor hooked up to a pulley system. He got his finger in between a belt and a pulley and cut his finger off.
The Contractor's Workman's Comp Insurance went up drastically.

Then there's always the thing about the tool's reliability, and the resultant labor costs of downtime when a cheap tool breaks and the job comes to a screeching halt.

Reno:

Could the difference of opinions in this thread be that you are a 'one man' shop, and for the 25 years I was active I had employees??

Not being critical, but my belief was investing in professional equipment. As Electure said, labor costs for downtime, or 'make this work', and keeping accidents & injuries low (Workers Comp Rates) offset the cost of the equipment.

There's no denying that a small shop has fewer opportunities to spread the cost of equipment over several jobs. Simply put, if you can guarantee a tool is used every day, it's real easy to justify the expense.

I'm currently working for a rather substantial firm, one with multiple crews spread across many states. The crew I'm currently on has 7-10 electricians; the next job will likely have three times as many. Work can be described fairly as commercial, institutional, or light industrial.

Our company vacuum is a well-worn Shop-Vac, probably retailing for less than $100. This vacuum has been easily out-performed by a similar-sized (but well kept) Shop Vac, a tiny 1-gal. Shop-Vac, and my new (and tiny) $21 bucket vacuum.

Previously, I was "in the area" as various "major" contractors did 'shut-down' work at a steel mill. These guys had threaders and benders, but 500's were still pulled using multiples of men and various jury-rigged equipment (cranes, fork lifts, etc.) Thousand-dollar vacuums? Not a chance.

It's easy to speak platitudes about improper equipment ... but, good heavens, we're talking about VACUUMS. With the vast majority of (even name-brand) vacuums going for less than $150, I have to ask: what's so special about a product that is priced at 15x the price? I would expect those who have such expensive equipment to be able to explain exactly why it's a better choice.

Cost aside, I see the Greenlee ad makes reference to 4" pipe and 2000-ft. runs. They also claim this wheeled behemoth is "hand carried." Good luck with that! More to my point, that's a bit more than what's needed by most pulls ... why use the semi-truck when the VW beetle will do the job?

Ever see the blowers used to inflate 'bounce houses?' Not much for pressure, but there's a lot of volume. I have often wondered if that's what would make a good tool to blow a mouse through the pipe.

Likewise, I note a variety of rather pricey bits Greenlee offers for the hose end. I'm sure others have found other solutions to this same issue. This thread is their chance to share their solutions with the rest of us.

Speaking of ferrets and mice, in my younger days I trained a mouse to run through conduit. At first, it was short pieces of pipe with peanut butter as a reward and he (she? I didn't check) got pretty good. On the first production try with a 2" pipe, I ran the mouse in the wrong direction. The run ended with a 5 foot drop into a live panel. After that, we could still use the mouse but we needed a vacuum.

While we're speaking of ferrets Reno, you're that not far off base.

One of my ex-employers bought enough from a wholesaler that he and 9 other contractors were given free 10 day trips to London.

When they were visiting Buckingham Palace, they learned that all the underground conduits (originally installed in the 1910s and '20s) used ferrets to pull the strings through them.

Saw in the paper a few days ago, that the Parliament building in London is in serious need of renovation. Bad roof, ancient wiring, and similar issues. Wiring probably done back when they used ferrets.

OK I will say that using CO2, or compressed air, may be easier to setup on site. Even that a smaller shop vac would be convenient, and should be 'easier to haul'.

When we were on a site with no 120/240 we had a genset. There was one on the bucket truck, and another could be from the shop. PVC jobs had the hotbox, and/or the blankets, Pipe most times had a power bender, and the 'big' pulls had the tugger. Sometimes it may have given the appearance of a Greenlee site demo.

No, the equipment wasn't used daily, but it was used when it was needed. A sort of bonus was the 'rental' from others who had a need. Ranged from 'favors' to $$$.

Same in Vienna, but probably no ferrets. I've seen pictures of exposed K&T in utility areas! Apparently driving huge arrays of incandescent bulbs used both to light the plenary and to melt any snow and ice from the glass roof.

Well, if this current job is any indication, here's what needs to be done to ensure a painless pull:

First, for any long or complex run, consider 'going up' a conduit size.

Next, pay particular care to your transitions. Many folks 'stub up' in steel, and do the bulk of the underground run in PVC. The transition can be a real 'catcher' of mice and fish tapes .... why can't our transition fittings have a taper to them, like plumbing 'bells' do?

Buried PVC connections need primer as well as cement, and a wrap of duct tape isn't a bad idea. EMT connections definitely need to be wrapped, or otherwise sealed, on long runs. You want to keep water out, if you can. (On this job, we even had an overhead run fill with water!)

Tape itself doesn't seem to be enough to protect your stub-ups. Somehow, the tape gets torn and crud dropped in. Deliberate malice or just Murphy's law? I don't know- but next time I might try attaching a soft foam plug to the pull string, just inside the pipe, at either end.

Protect your threads on stub-ups with couplings and proper pipe plugs.

This job has also shown a real need to brace the **** out of the stub-ups, to preserve their alignment during the pour, etc. This means I'll be burying some strut, running the conduit within rigid sleeves, or taking other additional measures.

Your vacuum need not be large. You don't need a big tank or a high-horsepower motor. Ironically, on this job we had a little 1-gallon Shop-Vac out-pull a 5-hp, 10-gal heavy duty vac. It's not so much the pressure you need, as the air volume .... remember, NO vacuum can create more than about a 14-psi suction.

Which, of course, brings up the condition of the vacuum. There's an argument to be made for using a dedicated vacuum ... and, in any event, to protect the vacuum with the best filter you can get. Vacuum performance is dramatically affected by even a microscopic amount of wear on the impeller ... and drywall dust is instant death to blower performance.

I spent about $15 on a "micro cleaning" kit that provided me with various attachments. With a modest amount of tape, I can now reach into conduit, even when it's off to the side of a mud ring, and get a good seal. I'm essentially duplicating the big Greenlee fitting- but in a smaller, more maneuverable size. Plus, the mouse won't get sucked into the vacuum; instead, it sticks onto the end of the nozzle.

Ironically, the $21 bucket-top vacuum seems to best fill the bill. Heck, you can even find 3- and 4-gallon buckets to mount the top onto, making it much more ladder-friendly. The 1-1/4" hose seems to move plenty of air. Best of all, you can store the hose, etc., in the bucket between uses.

(Full disclosure here: I'm now working with a trade tool manufacturer to develop a vacuum targeted to our needs- for less than a car payment, let alone the cost of the whole car!)

This job has been a wire-pulling nightmare. I have two pipes, full of wire, that had to be abandoned. For both, we got the wire about 90% through before it stuck, and could not be pulled out. Think: 5000 ft. of #10 wire lost. Sort of puts the cost of PVC primer and duct tape in perspective.

Over the years, my crews and myself must have always had a 'lucky charm' in our pockets.

"Think: 5000 ft. of #10 wire lost"

I have to feel your pain Reno. Yes, I was (and still am) a preacher of using conduit sizes larger than the code min.

BTW, never primed or taped a PVC run.

With a vacuum all you get is what the motor can deliver. With a compressor, you can store the energy in a tank and your limitation is how fast you can get the air out of the tank.

A piece of soft plastic tied into a balloon shape seems to work better than a factory mouse.

You should get a patent on the tapered fittings.

I've been using strut on stub ups through concrete. Is there another way? If the stub is ENT (Coreline) I sleeve it with vacuum line duct. I also run spares for anything that can't be re-done overhead later. It's pretty sad how much damage the cement guys can do.

Prime PVC fittings?

I don't think it is a bad idea to prime RNC connections. It is not as much the priming function as simply cleaning it but the cement seems to work better. You really do not want a joint to pull open when it is back filled.

To be clear, there is no "mea culpa" here. The underground pipe was run months before I ever saw the job. I can't speak for the original quality of the job, and it's anyone's guess what happened in the meantime.

In perspective, I'd rather be a bit anal and overly cautious now, rather than fuss & cuss later!

I noticed in today's "Electrical Contractor" magazine that Bridgeport is plugging a whole line of transition fittings. Perhaps these are less likely to cause problems than a field-expedient improvised transition assembly.

Sure would have been nice had NEMA specified the same ID for ALL conduit types! That small lip can be just enough for the wire to catch.

As for compressors ... I have no objection to the method. It's more a question of what you have available. On this current job, we have not had a compressor available- but we have used vacuums in tandem (one pulling, one pushing).

Best results were with a 'real' (foam) mouse and jet line. Yes, we know the plastic bag trick, and it was used several times, but the mouse worked better. The only problem was knowing when the mouse had arrived at the other end; often we had no idea it had entered the vacuum.

Jet line was followed by pull string. Then a mouse was pulled through several times - both to clear debris as well as to spread lube. Then a real rope was pulled in. Wire 'heads' were stripped of insulation, staggered very well, and the wire itself braided back onto itself. A very long, smooth, skinny head that did not depend on tape to hold it together.

Having just come out of my first solar field job (Which I came into about the 2/3rds point) I must say that the common sense (and code practices) that a general electrician uses when it comes to conduit installation did NOT reach the design phase of this job. I saw the most bizarre things over there....

2" PVC 40 stubs coming from a pad, had 1" "duct" shoved inside maybe a foot and then duct seal was stuffed around the 1". This duct was for fiber with was about 1/2" diameter and runs ranging from 400' to one just above 3500'! Through this we were expected to suck a string through. Unused conduits were stuffed with duct seal. (There was literally 2 pallets of duct seal on this job and nothing was "fire rated". Duct seal was easier to find than duct tape! )

We managed to get string in some of the runs with a large shop vac and generator. For a couple runs we "borrowed" a hydro dig machine that was onsite and used the vacuum hose on it, still having to use a slinkied fish tape to catch the balloon in the 2".

Did I mention there were up to 7 - 90° bends in some of these runs???

We ended up using a pulley attached to a Landall forklift and an atv to do the pulling. Some runs made it, and on some we snapped 2500# muletape. A kellems and a 5 gallon bucket of aquagel was used on every run.... Eventually I found out that this ducting was run through some bizarre routings around the solar tables "because thats what they drew on the print!". (One run was about 450'-500' if you walked from end to end. The pull used 1486' of fiber in the ground somehow???)

The job was supposed to be done last August and the group who owns the field finally kicked the EC off the job and hired another one. I'm deciding if I want to roll in with the new EC and take on the headache I know this place will be with the over strained fiber pulls, grounding issues and who knows what else. Lots of OT (7 X 12's) so it'll be nice for the bank account but will I live to spend it?

FWIW ... I've 'partnered' with a tool company, trying to develop a practical vacuum specific to this task. That is, to suck lines through and to blow lines through ... NOT for cleaning up the job site. The tool will be corded, and intended for nothing larger than 1" pipe.

The hard part, as you might guess, is getting access to the pipes. Once the wall is closed in, that mud ring is not your friend.

Meanwhile, the capabilities of the modest bucket-topper vacuum continue to impress. I've found it will fit in a 3-1/2 gallon bucket, like the ones used by the tile guys. There's still room to store your hose, etc., in the pail.

I live in the land of improv. Any vacuum I can get my hands on, duct tape as necessary, a plastic bag (thicker the better) and some sort of durable string. Pushing the line in works ok but I think sucking is better and safer. I've seen string shot into an underground conduit to a hot panel.... And there was water in the pipe....