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Homemade Electric on/off box

Discussion in 'Lighting and Electrics' started by TupeloTechie, Jan 14, 2007.

  1. TupeloTechie

    TupeloTechie Active Member

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    I have know idea what this is called, but a few years ago I was working on a show and the TD made a box out of wood that housed about 4 residential light switches (on the top) and a residential electrical outlet on the back. He had it wired so you could plug a cable in and it would supply power to all 4 switches, we used this to control a couple of florescent blacklights, a strobe, and a disco ball, because we didn't want to dim them. I need to make one of these for an upcoming show, I have built the box and installed all the switches and outlets from memory, but, I can't remember how he wired it. I was wondering if anybody knew how to wire it so I could get switchable power to each outlet from one plug?
     
  2. Footer

    Footer Senior Team Senior Team Premium Member

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    A firetrap is what I call it. You can not have any type of connections inside a wooden box without being encased in metal, period. I would suggest going out and getting about 4 or so double gang boxes, mounting them on a piece of ply, and then do all the connections inside the junction boxes and running cable with retention clips between the boxes or something along those lines. One of the last theaters I worked in had about 10 AB switches built in wooden boxes next to the dimmers, and the first thing i did there was rip them out. They each had evidence of charred wood, so take that into account. As far as the wiring goes, I assume you want 1 120v in, going into 4 switches, then going to 4 outlets. Its as simple as splitting the hot wire to each switch, then running the switched hots to each outlet, and then split the neutral and grounds and run it to each outlet.
     
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  3. TupeloTechie

    TupeloTechie Active Member

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    Do you think if I covered all of the inside of the plywood with a thin sheet metal it would work? If knot I'll just go buy some gang boxes, thanks!
     
  4. ship

    ship Senior Team Emeritus Premium Member

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    Agreed... (not the tin coated plywood box but the "fire trap") and also, if you don't remember how to wire it, you should not be wiring it. WAY TOO MANY DETAILS, that is beyond the - how it's wired to wiring it safely.

    Get supervision with the TD or ME in doing this or a qualified licenced electrician to teach you both how to do it, and how to do it safely for this thing.

    If nobody about to help... don't do it or try harder to find someone that knows the NEC and how to do it according to the code / much less safe and normal standards.

    Could be that the old TD had it in a plywood box to house the thing, and it's possible, but either it was metal boxes in that box and the box was to make it nice, or it was "old school" you are best off not re-producting. What ever the case, more instruction and especially supervision is required. We all learn somewhere - better now when your interest is high than learning after it catches fire or shocks someone.

    ... Wiring... dangerous! Remember that - get proper instruction before doing it.
     
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  5. Van

    Van CBMod CB Mods Premium Member

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    I think footer explained the wiring perfectly and ship explained the issues. If you didn't understand exactly what footer said then do not attempt this project. Find someone to help or teach you how. Find an electrcian, and ask them to supervise, a lot of guys would be happy to help you out. I can't impress on enough how dangerous improperly wiring even a simple device such as this can be.
     
  6. ship

    ship Senior Team Emeritus Premium Member

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    Of these cautions, you will hopefully note that we are not attempting to say that you cannot do this persay, or should not at least be very much involved with doing it, it's only that you should not by way of to what extent we understand the question be doing it in innitial or subsiquent reply questioned which sort of throws up a red flag.

    Believe me, we have most all of us including me started doing such things in the industry such as to the extent of your understanding and intended materials. Harsh way to learn and it's intended by all to save you of potential life and safety risks we learned by way of. Been there, done that with the plywood box type stuff. Done in the past, don't do it any longer.

    A book called "Old Electrical Wiring" goes into great detail about even applications of the past where wood were thought a sufficient insulator, and it is as long as dry and there is no sparks such as a non-commercial grade switch just might have as a part of it. Use of other than commercial grade switches and receptacles and or plugs on stage is against the NEC. Many applications of outlet boxes (1900) boxes are also against code to use, but can be - note the plywood backing but there is rules to it - it's a support structure to the boxes when painted and installed for temp. use. Lots of details about what you intend. Simple enough but lots of little assumed details to learn one would not otherwise consider.

    Hope it helps more than telling how to do it. Eyes on your project will in this case be much more help than advice on line. Need to see what type of wire you are using, what the length of stripped wire is, what cord and strain relief is in use etc. In theory, there must be overcurrent protection on this "device" and a incicator light that indicates it's of live power... many other details that are either NEC or waver type things but very specific.
     
  7. BillESC

    BillESC Well-Known Member Premium Member

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    Why anyone would build such a device is beyond me.

    This is an 8 channel switch panel, the on/off rocker switches are rear lit when on, it is rack mountable and each switch has a corresponding grounded outlet on the back of the panel. All for around $ 25.00

    [​IMG]
     
  8. soundlight

    soundlight Well-Known Member

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    I second BillESC's response, there are a number of pre-built switch packs out there that are going to cost about the same as you trying to build one yourself.

    If you end up building it, have an electrician check it for you, and use double, triple, quadruple, whatever gang you need boxes. Just build a box that you can nail the multi-gang box(es) in to. Make sure that everything is properly grounded, and that everything has wall plates.

    I built a dimmer box once, with household dimmers, and I used a triple gang box for three dimmers. I had a separate input and output circuit for each. So, unless you're dimming, get something that already exists for your project!

    Again, I'm with everyone else - DO NOT USE WOOD AS THE PRIMARY ENCLOSURE - USE WALL BOXES!! This could be a huge fire hazard, and could be a dissaster if not wired properly. If you know an electrician, or if you are in a school system (in which you can contact the school our county electrician), have them check this out for you before and after you finish it! And maybe even help you build it. Mak sure that you do all of your grounding properly.
     
  9. TupeloTechie

    TupeloTechie Active Member

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    ok, the reason I am building one is that I have all the materials, (except gang boxes), which I will buy, I know that you all are trying to help me, but I need this very soon, I have read a book about home wiring, and my brother has helped an electrician one summer, so he knows alot about them, but I was wondering what it the safest way to split the hot and neutral. And the best way to ground this box.

    Thanks to all who helped, I probably would have blown myself up by now if it wasn't for you.
     
  10. n1ist

    n1ist Well-Known Member

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    Judging from your questions, I would also suggest you don't try to build this yourself and use it in a public place. The liability and safety issues are too great.

    You say that you have all of the parts except the box - what kind of power cord are you using? What kind of cable clamps (no romex/mc clamps allowed)? What kind of wire inside the box? How are you grounding the box? What size wire nuts will you use to split the hot wire to the switches? What kind of box do you plan to use (no boxes with knockouts)? If the receptacles mount to the covers, do they mount with more than one screw (code requires that now...)?

    I'm not saying that you couldn't do this safely, but you have to be very careful. If you do build this box (or any other electrical project), have someone who really knows electrical code look it over, and don't believe everything you hear at the local home improvement or hardware store; you would be amazed what I have heard there...

    To answer your questions, I would use a wire nut to split the incoming hot to the pigtails for each switch (check the box to know if it can handle the 5 14ga wires you plan to use). You can do the same for the incoming neutral or daisy chain it from one recept to the next. Tie all of the grounds together and run a wire to the green screw at the back of the box; you can get ground pigtails with the screw from the hardware store.
     
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  11. soundlight

    soundlight Well-Known Member

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    I would make sure that all of the wire nuts are hooked up in the gang boxes, and there are only insulated wires inside the box.
     
  12. highschooltech

    highschooltech Active Member

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    Wow, this has dangerous writen all over it. Short circuits are bad, they spark and start fires if there are flamible things in the area like wood.
     
  13. ship

    ship Senior Team Emeritus Premium Member

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    Below is some things to study and sugguestions on materials that often would be used. It is recommended that you do not build this proposed box but for education value or if you are going to do it any way, here is the concepts to look into. Not as simple as just wiring up a bunch of switches and outlets - nor even dimmers to outlets and cord. There is some very specific rules and even a 1900 wall box is frouned upon. Often the slugs from such a box other than in a wall get knocked inward and can short to even an electrical taped live conductor or screw. Wall boxes are not recommended to use for any portable application.

    If your brother has had sufficient instruction in this he might be qualified to supervise it, one summer however does not always mean sufficiently trained as an electrician - more trained in hanging the boxes and other rough in work. Could be and possible, kind of depends upon what he was doing and how much training he had. Still it's a good start and hopefully your brother if there is something he is not trained in will have a contact to ask. Stressing the hands on, eyes on the project.

    Like Bill's solution, quick and easy, save the parts and have something really good and UL listed for the price it's going to cost you in follow up parts. 1900 boxes, covers etc, or if that is not expensive enough the cost of removing inventory from your stock that will at some point need replacement. $25.00 is a good price for what it is doing. We are talking about indicator lights to show live circuits - required, UL listed, Overcurrent protection, rack mounted and case grounded. Much less looks nice and professional.

    Again with the terminology that sends up red flags: "I was wondering what it the safest way to split the hot and neutral. And the best way to ground this box." Split the hot and neutral... you might know what you mean but such words send up red flags with me thus also the concern that most share. Terms are a part of understanding. Look back at such terms five or ten years from now and you will understand the red flags about the intended project still. If what above means how to tap the hot and neutral conductors to supply multiple switches and outlets or something similar in terminology, if the thing is not portable and temporary in construction, than a properly sized wire nut would be sufficient. If portable, a cap splice is normally preferred as wire nuts have the nasty habit of coming loose. This or sending the power in cables to a Millenium strip for proper distribution. All assuming that before you distribute the power, it's line in to over-current protection such as a circuit breaker or fuse as required. Otherwise what happens if of these switched circuits you pull more than the rated amperage? What wall outlet this is plugged into won't protect against voltage drop of the load right away - read in your electric's book about "sub-panels", this is for all intensive purposes what you are doing here. If more than six switches you will be best with a circuit breaker or need to have a switch to act as a master to kill all switches.

    Ok, the neutral must be isolated from the box (for all intensive purposes much of what you are doing is a portable sub-panel even if using switches instead of circuit breakers) - again the wire nut and or millenium bar or isolated neutral bus bar depending upon the application.

    The ground is required to go to the back of the box and be attached to it by way of ground bus or thru the threaded hole in the back of the conduit box. From there if two or less things requiring grounding, you can send a 6" grounding wire up to the device. Otherwise as long as your boxes have box to box connectors and a secure mechanical ground, the second grounding hole can be used in the second box with the 6" tails. Best to use a grounding bar for all grounds but it's a question of how to and box fill. This is not some electrical box installed in a wall but still must comply with "box fill requirements."

    The "box fill requirements" will be in the book along with how to do grounding and details about this.

    Gauge of wire... don't use less than 12AWG if you can help it. Unless your over-current protection on the device is specifically 15A and cannot be changed to a higher amperage, it's a bad idea. Cord no longer than three feet and the same wire gauge is optimum. Type MTW conductors be it stranded THHN/MTW or specificially type MTW as different is what is normally used. Solid core wire for portable appications - even if within the box is not done. Cable feeding the contraption should be 12/3 SO if at all possible but 12/3 SJ would be acceptable. If you need a longer extension to feed this thing, do an extension cord.

    Each switch and receptacle needs to be commercial grade - remember Bill's above $25.00 box above? Price out the commercial grade switches, much less just one mini-breaker and you just went over budget. The NEC is very specific about not using home owner grade devices in a theater or place of assembly. As a given the above switch box probably won't be using commercial grade receptacles, but it is a UL listed device, your's will not be and needs to comply in all possible ways with the NEC.

    Next, you need an indicatator light for each circuit and one for the main power in. This is useful in letting you know what is live and at very least in the box being live a code requirement for a portable distribution box.

    By code, electrical boxes are not structural nor are you allowed to be using a line voltage pendant or remote switching device. The conduit boxes need a painted plywood backing if attached together and if at all possible this thing needs mounting to a table and or wall so as to prevent anything bad from happening should it fall over for instance.

    That's all preliminary type stuff, again eyes on site will show proper strain reliefs, and lots of other stuff not covered. Also, anything above doesn't even mean that it's accepted by your local code or a inspector just seeing the gear won't tag it for violation of the code because it's a tricky thing what's permissible or not. Beyond all this, get what you create inspected by the supervisor responsible for the theater and have that person sign off on your work. Liability of this box must be with the person on paper responsible for it and all lives assembled within it.

    Highly not recommended to do this project, have your brother look over his copy of the NEC about these concepts expressed, verify the ideas and inspect the gear you currently have to do this project with.
     
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  14. PhantomD

    PhantomD

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    This thread is going to give me nightmares forever. :!:

    I get an electrician friend of mine to do all that stuff, while I do up his TV stuff and computer. He is unfortunately a crack-shot with audio so I can't help him with that!
     
  15. TupeloTechie

    TupeloTechie Active Member

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    hey, just to save people from the nightmares, I was at guitar center the other day and picked up one of those boxes like Bill mentioned, I have no idea what I was thinking, I can't believe I tried to build this!

    BUT... THANKS to all those who helped me out, This thread has taught me a lot about electricity!
     
  16. Van

    Van CBMod CB Mods Premium Member

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    Yay !
    < van let's his breath out finally.>
    ;)
     
  17. soundlight

    soundlight Well-Known Member

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    HURRAH! HURRAH! The end of the world is not now at hand!

    Well, it's good to know that you learned a lot about electricity.
     
  18. BillESC

    BillESC Well-Known Member Premium Member

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    GC gets another sale... :(

    What did it cost you with tax?
     
  19. TupeloTechie

    TupeloTechie Active Member

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    $32 :(

    If i wasn't in need of it buy the next day...

    but then again, I probably would have electrocuted myself If I didn't...

    :rolleyes:
     
  20. ship

    ship Senior Team Emeritus Premium Member

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    By the way in what was not caught... "Millenium strip" was incorrect in my terminology, it's "Marithon Block" that would be the proper term for what I was thinking.

    None the less, good to see that you bought the component that did what you intended rather than built it which might work but would not work within the intent of safety.

    For me at the moment, I'm working on a 30 Amp three phase to six circuit 20 Amp two phase "Emergency Stop" system "E-Stop" component that powers up a bunch of ribbon lifts for a tour. Three emergency stop button locations to the kill switch power, lots of indicator lights, circuit breakers and a Socapex output that's wired so as not to blow up a 120v output plugged into it in adding to the wiring, 5V remote power to the switches, circuit boards and relay switch difficulties all fitting into a two rack space component.

    Beyond that, the production designer wanted this "E-Stop" power to the ribbon hoist/lifts to be universal in 120v and 230v Volt American/Euro wiring. Yea, that's the great concept in wiring these days... stuff that will work here and overseas. Yea.. my circuit breakers would work in eigher voltage as the only question asked.. but given the details it would require total re-wiring and the electronics package would not accept dual voltage without a switchable power supply circuiting. This plus our Socapex wiring unique to the US as the alternative in safe wiring here would throw further a wrench into the works. Did the E-Stop, only for 120v/208v couldn't do it for 120/208 plus 230v short of a lot of extra circuiting.

    Sort of like the switch discussed, much more complex. At times you have to do such things, best to buy them - if it existed, we would have bought it, since it didn't, much less DMX controlled ribbon lifts didn't exist before we made them that became in part my job.
    If not available, there is no replacement for study and experience. In my case, our other ME took a good long look at what I was doing and gave his seal of approval to it also - even I don't hack wire stuff together without getting in someone else to have a look at what I'm doing. Nor does he do stuff I don't look at.

    That's our as it were UL listing system given lots of Insurance and experience professionally in doing that sort of thing for a living. Were it not for such a background, aways better to buy what's pre-built or at very least be absolutely certain to all extents available and beyond that possible that you can ask, in what you construct is proper and safe. Cover your rear. Worst that can happen is that you learn something. Best that can happen is that it works as designed and that person you ask starts asking you for advice.
     
    Last edited: Jan 22, 2007

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