120V Power Snake

Discussion in 'Lighting and Electrics' started by StageTech620, Nov 26, 2015.

  1. StageTech620

    StageTech620 Member

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    First, Happy Thanksgiving to you all. Over the past few years, I have seen numerous cables, both homemade and store bought, which are like a FOH Audio Snake. Instead of having 4 different extension cords, it is a power snake, with 4 channels of independent power. So the male ends plug into a dimmer, and the female ends go to a light stand, with 4 ERS Fixtures. I cannot seem to find how to build one or buy one. Any help would be very appreciated. Thank You in Advance!
     
  2. JD

    JD Well-Known Member

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  3. StageTech620

    StageTech620 Member

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    Hello! Thank you for your quick response. I know about Socapex, but it is simply to expensive and probably too complicated for our needs. Attached is a picture of what i am looking for.
     

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  4. MNicolai

    MNicolai Well-Known Member Fight Leukemia

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    You can't find one commercially available because that's not a legal cable.
     
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  5. StageTech620

    StageTech620 Member

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    hmm. So you are saying that these are not safe to use? Could you explain that to me?
     
  6. coldnorth57

    coldnorth57 Active Member

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    More than one power souce.....
     
  7. SimpsonAV

    SimpsonAV Member

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    Nothing wrong with that.. assuming each plug only goes to one socket and the box internals are fully insulated
     
  8. MikeJ

    MikeJ Well-Known Member

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    You wont find that often, mostly because its almost as or more expensive than Soca. That setup uses 12 conductors for 4 circuits. Most soca has 14 conductors for 6 circuits. This is because in the multi connectors, three circuits can share one ground wire.

    The costs add up a little more when you, then add a break-in and out for the ends, but if you are skilled at soldering you can make your own connectors and save some money.

    Now, consider that (4) S4 fixtures can easily run on a small dimmer pack, powered from (2)20 circuits. That could actually be cheaper and soca and break-in/outs.
     
  9. venuetech

    venuetech Well-Known Member Departed Member

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    The box with knockouts is one issue.
     
  10. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    This is slightly misleading. All six grounds share two conductors.

    As to the cable pictured, one really wants to know what is happening inside the heatshrink under the Kellems grip.
     
  11. JD

    JD Well-Known Member

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    Have to go back to the original question in my mind: Why do it that way?
    Seems like it would cost less to grab a couple of shoe-box dimmers and eliminate the need to run power cables to the FOH. For what a 100' Soca with breakouts would cost, you could probably pick up 3 packs and a small board. (Elation scene-setter)
     
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  12. MNicolai

    MNicolai Well-Known Member Fight Leukemia

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    The box with knockouts is one issue as already noted. That's a back box meant for installation, not for portable use.

    The second thing that's suspect is the transition from the multi-conductor cable to the x/3 cable under heat shrink. I haven't verified that this is a code issue but my educated guess is that you're not allowed to do that. Aside from the durability of heatshrink, you have to be concerned about how the splice is made internally -- probably butt splices, which in any portable cable is a likely point of failure in addition to probably being a code violation. Any commercially available breakouts have either molded transitions or all of the x/3 cables route all of the way into the housing of a 19-pin connector.

    The third thing is that your x/3 cables look small for this application. They look like they're either under-sized or more likely that they're SJ-type cable rather than SO-type. SJ-type cable is allowed in adapters, such as in a 6-circuit breakout cable from a 19-pin connector, but only as an adapter cable up to a certain length, which the pictured cable certainly exceeds. Article 520 of the NEC (the Theater section of the code) specifically prohibits use of SJ cable in theater except in certain circumstances that this cable would not qualify for.

    I'm sure you could build a version of this that would be legal with an appropriate back box, appropriate transition, and appropriate cable type. You'd probably have an easier time buying 6-circuit cables on the used market though. They aren't inexpensive, but next to truss. cables are probably the least likely item to depreciate in value. Even if LED's take over the world and 6-circuit cable eventually becomes a thing of the past, there will always be money in copper.
     
  13. StageTech620

    StageTech620 Member

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    Very interesting. I sometimes work with non-DMX systems, so there are basically just Edison plugs on the back of the lighting console. But everything all of you have said makes quite a lot of sense! This was more of a FYI thing than me actually wanting to do it. I'll stick with my "shoebox" dimmers.

    Also, MNicolai: What do you mean by SJ Cable? Unless I am wrong, SJ cable is what most extension cords are made out of...

    Thanks!
     
  14. iLightTheStage

    iLightTheStage Active Member

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    Try L21-20 or L21-30 cable and their break-out boxes. That gives you three circuits in a proper way.
     
  15. MNicolai

    MNicolai Well-Known Member Fight Leukemia

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    You are correct that if you go to a hardware store you will find plenty of SJ and similar type extension cables. It's popular because it's less expensive, and because it suits most people's needs. Current electrical code has deemed it not rugged enough for use in theater however, and because it thinner insulation is only rated to 300V instead of 600V.

    For many uses, SJ cable is adequate in how rugged it is. But in theater it isn't sufficient because it could be installed for long periods of time, have fork lifts driven over it, be subjected to sustained higher-current loads, and placed in close proximity or in direct to high-temperature heat sources. Theaters are much more readily able to push an SJ-cable to its limits more conventional users.
     
  16. MNicolai

    MNicolai Well-Known Member Fight Leukemia

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    No dice.

    The break-out boxes are legal, but in this case where the inputs are all single-pole 5-15R sources, the necessary break-in cables wouldn't be. If you were feeding from a proper 3ph receptacle it would be allowed, but creating a break-in cable with multiple 5-15 male connectors and adapting into an L21 would create a cable that could be connected to a 3ph device, but could have all of the phases out of order -- or every pole of the 3ph connector could be on the same phase. Adapter cables that allow for "faux 3-phase" aren't acceptable. There's also the issue that you if used such a cable on a 2ph or 3ph device and unplugged one of the input cables at the break-in, power could be sent out to the device on one of the connected phases and then returned out on the disconnected phase to the prongs of the male connector that's not plugged in.

    Thus -- such cables fall into the wide category of cables I like to call "suicide adapters".
     
  17. iLightTheStage

    iLightTheStage Active Member

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    Ah, I didn't see that he wanted to have it as a break-in type cable. I always recommend using proper power distribution boxes.
     
  18. WVTheatre

    WVTheatre Member

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    You could use an SOOW cable, which IS rated for 600V (the amperage however depends on the wire gauge). These come in varieties of conductors on the inside, including 2, 3, 4, 5...
    A better option might be an ETC SmartBar (Which actually is a dimmer that hangs from a lighting stand, just provide your own dmx cable from the console). OR, ETC Pigtail/Outlet Boxes.
     
  19. MikeJ

    MikeJ Well-Known Member

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    You are right, the way I said that is confusing. The 2 ground wires are connected together to all of the grounding pins. 3 circuits are allowed to share one ground conductor, hence the use of 2 in each 6 circuit cable.
     
  20. MikeJ

    MikeJ Well-Known Member

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    Did you ask the OP if they had 21-20 or 21-30 receptacles available? I know the picture posted had an edison fan in, and what you mentioned would not be acceptable, but I don't think anyone asked if they had any other power connection options available.

    So, @StageTech620 do you any other power connections available that could allow an effective solution?
     

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