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Hardware

Pulling Wire Through a Central Vacuum System? 47

call -151 asks: "A friend of mine has a nonworking central vacuum system in her house and I was offering to help her use the tubing as conduits and pull cable to distribute her network throughout the place. Has anyone done this and have any advice to offer? It should go smoothly but I'm sure there are some things I'm not thinking about." Of course, not everone can expect to have a CVS (pun intended) in their own home, but this was just odd enough where it deserved a post. Anyone have any URLs that describe exactly what a Central Vacuum System is, and how it worked?
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Pulling Wire Through a Central Vacuum System?

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  • some advice. (Score:2, Informative)

    by laymil ( 14940 ) <laymil@obsolescence.net> on Wednesday October 03, 2001 @07:51PM (#2386311) Homepage
    ok...this may seem simplistic, but keep in mind the SIMPLE things when doing the wiring.

    Whenever possible try to go down through the tubing...it makes life easier.

    For long horizontal stretches, slingshots can be your best friend. (sounds stupid, but it works)

    A lot of your problems will depend on the width of the conduits...so try to run the wire all at once in bundles to make life easier.

    That's all i've got for now. peace.
  • Run extra cable (Score:3, Informative)

    by dustpuppy ( 5260 ) on Wednesday October 03, 2001 @09:03PM (#2386496)
    I'd run extra cable while you're doing it because it's a lot easier running a bundle of cables along a narrow conduit than it is to feed an individual cable through a narror conduit already filled with other cables.
  • by Rude Turnip ( 49495 ) <valuation@@@gmail...com> on Wednesday October 03, 2001 @09:50PM (#2386616)
    My mom's house has a central vacuum system, too. We've never used it in the 25 years that we've had the house, so the dust puppies living in its tubes must be ancient! Before my mom sells the house and moves, I'd like to run some CAT5 through the tubes and set up some keystone jacks in place of the current vacuum sockets. Then the realtor can say that the house is "wired for broadband internet and home networking." Should add a dollar or two to the market value :)

    For the unitiated, this is what a central vacuum system is all about:

    Imagine the telephone wiring in your house. Now imagine dirt, dust and tiny bits of garbage going through those wires and getting sucked into that little junction box in your basement. That is the jist of a central vacuum system.

    In the basement there is essentially a cannister vacuum attached to the wall. However, the motor is more powerful and there is a 2-3 inch diameter tube going from the top of the cannister into the floors and walls above. In certain rooms, there are vacuum jacks just like phone jacks, but wider of course. To use the vacuum, you insert a long, flexible tube into the jack. The end of the tube that goes into the jack is metallic and connects two metal contacts in the jack to turn on the power for the cannister in the basement. It's just like using the tube extension on a regular upright vacuum cleaner.

    I have 1000 feet of CAT5 on standby. All I have to do now is find the time to do this and also learn how to wire CAT5 into jacks. My words of advice are this:

    1. Make sure the tubes are relatively clear of debris. I've shone a flashlight into my vacuum cleaner tubes and the amount of stuff that rests on the bottom of horizontal runs of tubes is amazing.

    2. Check the local building codes to see whether or not plenum cable is required for a residence. It's sure required for offices around here. Plenum costs more, but it doesn't get smokey and toxic like regular cable in case of a fire.

    3. Unless your tubing is really complicated, you should have access to the actual tubes in certain parts of the house (basement ceiling, inside certain closets). If the tube is visible in certain places and then it bends up into the walls, feel free to cut yourself a little porthole into the tube to help fish the CAT5 through. Note: Make sure you follow tip #1 before cutting holes...or wear goggles :)

    4. Think about where a broadband internet connection would be coming into the house. Try to syncronise the location of the hub/switch/firewall/server room with this location.

    Other than that, the rules should be the same as if you're putting wire through any other object and I'll defer to the experts here for that advice. Good luck!!!!
  • by unitron ( 5733 ) on Wednesday October 03, 2001 @10:36PM (#2386799) Homepage Journal
    You'll need to do some research to see if the vacuum system's tubing is acceptable under your local building codes for running low voltage cable through (*Do Not*, under any circumstances, use it for any sort of power wiring, i.e., 120 V AC). If you don't do a legal install and have a fire of any cause later, you may well have given your insurance company grounds to dismiss your claim.

    As with woodshop sawdust collection systems, a central vacuum system should have a bare grounding wire already installed in all the pipes to prevent the rush of air through the plastic from generating enough static electricity to cause a spark that could ignite flammable dust and cause an explosion. Probably best to leave it intact.

    Assuming that the local building inspector gives you the go ahead (or if you're planning on some other installation elsewhere using "real" conduit), here are a few tips.

    Always install a pull rope of some sort so that you can install more cable later or pull the old stuff for reconfiguring.

    You can use a vacuum cleaner to pull the pull rope through the conduit in many cases (attach something a little smaller than the conduit inner diameter for the vacuum to pull on to one end of the pull rope), then attach another pull rope and the cable bundle to the far end.

    Sometimes you'll need a small gauge pull rope to pull another larger one through before you can pull the cable bundle through.

    Insulated 14 gauge copper is flexible enough to be used as the pull rope left in the conduit, and you can get it with insulation that's rated for installing inside conduit. Consult your local building code and inspectors to find out what color insulation will be allowable for a wire connected to nothing at either end except for something (non-conductive) big enough to keep it from falling down into the conduit where you can't get at it.

    14 gauge copper with some sort of smooth ball on the end (a big crimp-on lead fishing weight works well if you smooth off any rough parts) can be used to push through the conduit instead of pulling with a vacuum.

    Electrical supply houses carry a kind of synthetic grease that you can use to lubricate the cable bundle to make it slide through the conduit more easily.

  • by Dios ( 83038 ) on Wednesday October 03, 2001 @11:26PM (#2386920) Homepage
    What about using the vacuum to help run the wire? Tie some light but strong string to a sponge or table top tennis ball that will easily fit through the system. Put ball/string in outlet (tieing the opposite end to something..) Turn the vacuum on.. and when the ball hits the canister turn the vacuum off.. next pull the cat 5 with the string... Seems good in theory.. who knows in practice....

    Should be fun though!
  • tips & tricks (Score:5, Informative)

    by digitalmuse ( 147154 ) on Wednesday October 03, 2001 @11:37PM (#2386941)
    Having done this once, here are some tips when it comes to the actual installation. However, I provide the following caveats, so take heed:
    A) check with your town/city building inspector - you mentioned that you're doing this to help increase the value of the place when you put it on the market. You do not want someone to buy the place, then sue you for doing non-code work in the place when they burn it to the ground. This is a must. I would personally check with the building inspector and make copies of everything he says is applicable. I believed someone mentioned checking out what kind of line you can leave in the ducts as a pull-guide, again, check with the town.
    B) The system that I worked on had it's own integrated conductor system that used the flip-open facia plates to close(open?) a low-voltage circuit that triggered the main vaccuum in the basement. Once you've gotten all your guide-lines drawn, you should disconnect everything else electrical from the system. Label all the existing connectors, take it off, box it up, and stick it in the attic. When the Luddites move in in a few years, they may value the CVS more than a house-wide network.

    When I helped wire my friends house this way, we took a few lengths of wide cotton sash, and connected them to kite spools. Using them as a primitive chimmney-sweep brushes, we went one port at a time, and fed the rags in, feeding in a few feet of line, and then pulling back in most of it. The doubled-over loose ends along with the plunger action seemed to release a lot of the dust in the narrow ductwork (~2.0" dia.). Check the info on the central vaccuum unit, our's was marked that you should not use it continuosly for more than 20 minutes. Needless to say we took advantage of this to self-medicate ourselves during the scheduled downtime.
    We then repeated this for each branch of the system, cleaning out the collection bucket every couple times. Make sure that you get the entire length of the run, a person by the collection bucket will immediately notice the change in tone when the rag stops blocking he duct work, and starts trashing about in the collector.
    Once this was all finished, we then repeated the process, only this time, we fed the rags and lines down again, this time, we didnt' pull the rags back out to their starting point, instead, we pulled through enough slack to allow us to anchor the lines from each room outside the can. Label these lines, remove the rag, cut off the line outside the top-side vent, label this end as well, then cut it off. repeat with the next vaccuum connector.
    In the end, you'll have a spagetti-farm of labled strings coming out of the collection unit, and your house will be strung like a spider-web in a straw-factory.
    (at this point, we confirmed that all the lines were not snagged, then proceeded to unmount the CVS collector, motor, and the transformer for signal lines.)
    Now all your hard work has paid off, and you are ready to pull the wires. I would suggest starting top-side, no need to fight gravity on this one. Just connect your wire bundles up to the feed strings (along with a new 'safe-to-put-in-the-walls-sez-the-inspector' pull line) and have the guy downstairs start pulling down fresh coppera along with the new guide line.
    As always, go slowly, work with a partner on the other end, and be carefull. Once you've strung the CAT-5 up through the pipe, label and secure the new guide lines, mount you keystone jacks, punch down and test.

    As an added benefit, you can now truly say that your home network used to suck, but not any more.

    Good luck.
  • by dattaway ( 3088 ) on Thursday October 04, 2001 @02:06AM (#2387278) Homepage Journal
    Using a vacuum to pull rope is a good idea, but what I found best is nylon string and compressed air . You can push hundreds of feet of nylon string in seconds through hundreds of feet of any size tubing with your portable air tank. Pulling wire couldn't be easier.
  • Don't do it! (Score:3, Informative)

    by ivan256 ( 17499 ) on Thursday October 04, 2001 @09:46AM (#2387931)
    Though it may seem dumb to people like us (geeks), the central vac is probably more apealing to the housewife that is going to be moving in then CAT5 would be. Especially when you consider how cheap 802.11b equipment is, you should leave the central vac. You'll more likely lower the value of the house if you change it into CAT5 conduit.

    Unless it's broken. That's a whole different story.
  • by CharlieG ( 34950 ) on Thursday October 04, 2001 @10:42AM (#2388166) Homepage
    Believe it or not, there is special string made for exactly this purpose - called a "Line Package"

    It's a bobbin of string with a foam rubber end. The string is flat like dental floss, but MUCH stronger.

    You put the bobbin in the conduit, secure the free end and then blow/suck the bobbin to the other end.

    The advantage of this is that you are not pulling the string the whole way, it's just coming off the bobbin

    They then use that string to pull a yellow polypropylene (I think) cord through, and then use that to pull the cable

    You can get all of this (Plus pulling grease) at a good electrical supply house

    Check out:

    http://www.idealindustries.com/wi/PullLine.nsf

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