Analysis paralysis: low voltage cables through drywall

Discussion in 'Accessories' started by sleetdawg, Feb 14, 2017.

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  1. sleetdawg

    sleetdawg n3wb

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    As part of my new camera deployment, I'm ripping out the spaghetti pile of cat3, silver satin, Cat5, and various coax cables and replacing it with new Cat6 and RG6/U. I'll be pulling about 45 Cat6 and 15 RG6 cables through the attic to a structured panel in the only room on the second floor.

    I'm struggling with what fittings to use on the drywall to pull the cable through. It will be in a few bundles through some form of ports in the sheetrock. They will terminate inside the room on a patch panel. What do you guys recommend? I'm planning to pull a lot of the cable this weekend so I need to figure this out soon so I can get parts here. For some reason, I'm stuck on stupid and can't make a decision on what to do here!

    I've seen the following:
    1. Single to triple gang plates that have a brush opening. Each one looks like it will hold about 10 Cat6 cables per gang.
    2. Single to triple gang plates that look like a scoop. I haven't seen one in person so I haven't been able to estimate the cable density.
    3. What I'll call 'sphincter' plates - they have a rubber grommet in the middle that looks like low cable density.

    Please help me get over my analysis paralysis here :)
     
  2. spankdog

    spankdog Getting the hang of it

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    I assume you are pulling more cables than you can terminate on the wall plate itself? I've used a few of the brush type and the scoop type and obviously they will work just fine. I liked the look of the scoop better because you can install it where you cannot see through the hole into the wall. It looked more finished to me than the brush type.
     
  3. sleetdawg

    sleetdawg n3wb

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    Yes, I'm pulling about 60 cables total. I don't want to terminate them in the wall for cable management reasons. It is a long room with vaulted ceilings The walls are about 5ft. I'm doing built in shelves down the entire wall, and building in cabinetry one end hold the patch panels and switching/routing gear in a short rack.

    With the brush type I have seen, it would take 2 or three triple gang boxes to hold that much cable. Not out of the question, but it 'doesnt seem ideal in this case. I've thought about running them all through a double gang box, and then crafting something myself with a blank faceplate and some rubber edging after the fact.
     
  4. tangent

    tangent IPCT Contributor

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    maybe something like this:
    [​IMG]
    ELK-SWB28 Structured Wiring Box, 28 inch
    smaller ones are available. elk has more universal mounting holes than the competition. Don't buy the overpriced stuff that fits in cabinets like this.
    You could also put a piece of plywood on top of drywall and some sort of plastic bushing.

    don't use a patch panel for coax.

    Your built-in cabinet will likely require ventilation.
     
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  5. sleetdawg

    sleetdawg n3wb

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    The surface mount plywood and plastic bushings would work. I'll see what I can find in the way of bushings tonight

    What's the problem with coax on the patch panel? I'm using F-Type pass through keystone jacks on the PP terminate both the video distribution cables and demarcs for Comcast/DirecTV etc.

    I haven't designed the enclosure yet, but it will have ventilation. At the moment it's just a temporary freestanding rack. where the builtins will be.
     
  6. tangent

    tangent IPCT Contributor

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    You gain nothing using a patch panel for coax, you just spend a bunch of extra time and money and get a crappier signal as a result. There's signal attenuation at every connector and coupling you aren't going to be making frequent changes so there's no point.

    Use a patch panel for your cat-6, the losses in a lvds system aren't as significant.

    With some planning you can minimize how much of your temporary setup you have to redo.
     
  7. drew91101

    drew91101 Getting the hang of it

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    I like the sphincter plates personally. The brush plates tend to look a little nicer but once they are full of wire, it doesn't really matter. I use the brush plates when I'm hanging a tv but when I have to run multiple cables, I use the sphincter plate; they look a little neater with multiple wires compared to the brush or scoop. Just personal preference though.
     
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  8. vegaslineman

    vegaslineman n3wb

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    Is there anything wrong with putting unmanageded switches in the attic so you don't have to run all the cables into one room?
     
  9. spencnor

    spencnor Getting the hang of it

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    On many commercial installations an electrical conduit sleeve (short length of conduit) and plastic bushings are used for penetrations through sheetrock walls and ceilings. Just drill a hole through the Sheetrock matching the O.D. Of the sleeve. Choose a conduit size based on your number of cables. I'm guessing a 3" conduit would be more than adequate for your 60 cables and allow for future cables. Or if your cable drops need to be in different locations, then install a number of smaller conduit sleeves wherever you need them. After all your cables are run you can firecaulk and seal the cables in the conduit.
     
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  10. wantafastz28

    wantafastz28 Getting comfortable

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    Heat/dust, and it would suck to get to them if you had to unplug a device or the power to the switch.
     
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  11. TonyR

    TonyR IPCT Contributor

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    sleetdawg,
    In the quest to find the optimum electronic properties for your cables and the best method for the physical installation, please insure that the insulation and outer jackets of all your cables are rated for use in a riser with regard to fire resistance, low smoke, etc. It could be the difference maker in whether or not your home and loved ones survive what could have been minor fire damage. The link at the end below contains an excellent video of several different rated and one unrated cable responding to an applied flame. Pay special heed to the last video of the 'unrated' PVC cable and imagine a bundle of those types burning! Looks to me like the 'CMR' rated (riser, second video) would be an excellent choice or the pricier, low-smoke 'CMP' rated (plenum, first video). Also, be wary of counterfeit, offshore suppliers with false NFPA, NEC and/or UL approvals (as if you did not have enough things to consider!). Good luck with your project, I hope it all comes together well and works out even better.

    USB Cables, Computer Cables, Coaxial Cables, Audio Cables, Video Cables and Assemblies, Connectors and Supplies - www.L-com.com
     
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  12. eeeeees

    eeeeees Young grasshopper

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    Hello Group
    My technique for running cables thru various surfaces most particularly including drywall utilizes short lengths of PVC conduit. Actually any plastic available at Home Depot will do. Choose a diameter twice what you think you will need. Get a hole saw for the OD of the tube and a long drill bit (~10 inches) smaller than the pilot drill on the hole saw you get. If going from a un-finished wall thru to a finished wall a length of scrap wood that will span the wall studs is needed.

    Figure out where you want to pass thru and mount the wood across that point using a screw into the stud on each side. Using the long-small drill drill thru the wood and drywall from either side. If you like the hole location on the finish side you are good to go. If not drill another in a better location. When you are satisfied with the pilot hole location use the hole saw to enlarge the hole to the PVC OD. Cut two holes from opposite sides (now you know why the long drill is useful.) If going thru an outside wall slant the conduit hole slightly down to prevent water from flowing in. The cleat on the inside is important to support the conduit and keep it firmly located. Caulk with silicone to hold the conduit in place. The conduit ends should not be flush, 1/4 inch above is good.
    Stucco and plaster are hard on hole saws, you might want to get a carbide grit one or just run the holesaw in reverse when going thru the plaster.
    The attached pix demonstrate a couple of instances.
    If you are lazy a desktop grommet (for running a phone cord thru a countertop) works pretty good if glued in place.
    Eric
     

    Attached Files:

  13. tangent

    tangent IPCT Contributor

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    Yikes, this is up there with examples of what NOT to do.

    If you're going to run conduit like that at least put an LB where you turn 90 degrees though sweeps are easier to pull through. In a residential environment conduit that big is rarely needed.

    Outdoors drip loops are required and it's still too easy for water to get in if you do conduit like that.
    [​IMG]

    You should NEVER drill a hole anywhere near that size in a structural framing member (DSCN6708[1]), can't tell exactly what you drilled thought but that's a bit scary. Really no reason to drill a hole at all.

    Now for some better advice on running cables please read these, they are focused on home theater but still apply:
    www.hometheatershack.com/forums/home-theater-design-construction/6038-how-wall-wiring-your-home-theater.html
    In-wall wiring guide for home A/V
     
    Last edited: Feb 27, 2017
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  14. TonyR

    TonyR IPCT Contributor

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    Good point, tangent.
    That big conduit entrance outside caught my attention as well. Although the author stated "...If going thru an outside wall slant the conduit hole slightly down to prevent water from flowing in", my concern would be that birds and squirrels would surely be tempted to set up housekeeping in there. Another recent thread here discusses that issue exactly and details the damage those cute little tree rodents can do to your wiring and your attic.
    Dscn6707[1_small].jpg
     
  15. drew91101

    drew91101 Getting the hang of it

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    I'll post a picture of the side of my house when I get home but I had to run multiple wires from my attic to my basement and used 1.25" sch40 conduit down the side of my house with two 45 degree elbows and a 90 degree box at the point where the conduit meets the wall.
     
  16. eeeeees

    eeeeees Young grasshopper

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    Not to worry! The conduits going outside are stuffed with stainless steel pot scrubbers just to keep visitors out. The cables going thru are 3/4 inch hard line with 1.5 OD connectors so you need it roomy. And no structural materials were penetrated in the making of this post.
    Eric
     
  17. tangent

    tangent IPCT Contributor

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    You're still missing a drip loop on a lot of those cables and a little paint goes a low way towards increasing the lifespan of Ethernet cables left to bake in the sun.
     
  18. sleetdawg

    sleetdawg n3wb

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    Yes. I have about $500 in my switches alone; I'd rather not bake them :) Plus, I have my NAS, cable modem, and other equipment in the rack. None of that needs to be in the attic.
     
  19. sleetdawg

    sleetdawg n3wb

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    Pretty close to what I did. If I use firecaulk and need to add/replace a cable down the road, how will that work?
     
  20. tangent

    tangent IPCT Contributor

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    fire rated foam is probably easier on a larger conduit
     
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