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Dimmers Single/three phase wiring

Discussion in 'Lighting and Electrics' started by Anonymous067, Jun 28, 2008.

  1. Anonymous067

    Anonymous067 BANNED USER

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  2. Charc

    Charc Well-Known Member

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  3. JD

    JD Well-Known Member

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    If you are not familiar with three phase wiring, then you must get professional assistance. We can not give that type of advice on this board.

    Basically, the components you have will work. I suspect you will not be wanting to rewire your dimmers for each job, but two distros can be built. Each of the packs would be wired for 2 phase legs as per the third diagram in charco's pdf. Your single phase distro would put all the L1's on L1 and all the L2's on L2. Your three phase distro would have each pack bridging two legs in rotation so that each main leg would end up with two dimmer legs on it. This is not something you want to do yourself as there are several considerations that must be adhered to. Although the hot-to-hot for single phase is 240v (US) and the hot-to-hot on three phase is 208v, it is only the hot to neutral that the dimmers will see, which is 120v in both cases.

    Be aware that there are two different versions of 3 phase power and one of them is not suitable for operating these dimmers. (oversimplified)
     
  4. Anonymous067

    Anonymous067 BANNED USER

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    Whooaaaa...slow down.

    Now, I'm no dummy, I wired my own house for wiring, but even that PDF that was in the post above, didn't make sense to me (I'd already looked at it several times in the last few months).

    And also to clarify, I'm using single phase.

    Basically, I have a diagram of the terminals inside the dimmer, and I need to know what size circuit to run, and which wires to connect where.

    I'm guessing somewhere in the range of 20-30 amp 240 volt circuits?

    Sorry, but I'm still majorly confused.
     
  5. Anonymous067

    Anonymous067 BANNED USER

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    Okay....I'm officially an idiot. I'll admit it.
    I just looked at the PDF again...and somehow it somewhat makes sense, still don't totally understand it, but I do somewhat.

    So, correct me if I'm wrong, but what I'd have to do is take the 1B and 2B (factory wiring, no?) on the circuit breaker side, and move to appropriate terminals, and L1 would have the first leg of the 240 and the L3 would have the other leg of the 240 circuit?

    I can't believe I didn't catch this earlier, either that or I'm really really off.
     
  6. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    As [user]JD[/user] stated, when in doubt, consult a qualified professional; or call ETC Service, 24/7/365, toll-free at 1-800-688-4116.

    For an SL620x (6 x 20A dimmers):
    For three phase service, 120/208VAC, 3Ø, Wye-connected, 4-wire plus ground, 40A/Leg: dimmers 1&2 are on ØA, 3&4 are on ØB, and 5&6 are on ØC.

    For single phase operation, 120/240VAC 1Ø 3-wire plus ground, 60A/Leg: dimmers 1,2,3 are on one hot leg, and 4,5,6 are on the other hot leg.

    For an SL1210x (12 x 10A dimmers):
    For three phase service, 120/208VAC, 3Ø, Wye-connected, 4 wire plus ground, 40A/Leg: dimmers 1-4 are on ØA, 5-8 on ØB, and 9-12 on ØC.

    For single phase operation, 120/240VAC 1Ø 3 wire plus ground, 60A/Leg: dimmers 1-4, 5, 6 are on one hot leg, and 7, 8, 9-12 are on the other hot leg.


    As far as what size circuit to run, consult the NEC and your local codes as to the proper wire size and type for the above loads. (Hint--from the manual:)
    Strain relief for up to 6/5 SO cable provided for power input to terminal lug
    • Input lugs accept up to AWG 2 cable
    min. 75°C or equivalent. Use copper conductors only.

    I'm not sure exactly what you mean by a "backyard/portable project", but be aware these packs are not listed for domestic, outdoor, or wet-location use.

    Good luck.
     
  7. Sean

    Sean Active Member

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    As D. just explained:

    Three phase takes 3 120v legs. Single phase takes 2 120v legs. You're just taking the middle dimmers and splitting them so one goes to L1, and the other goes to L3.

    I'd respectfully suggest that you consult someone more experienced. Based on your questions, I'm not sure that you do truly understand what you're doing.

    --Sean
     
  8. TimMiller

    TimMiller Well-Known Member

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    I dont think he has a question about the difference between single and three phase, but a question of what factory wires to move to make it single phase. From what i can see from the pic, you just move wires 2A, and 2B respectively. If they are not labeled 1A and 1B, just move one of the two wires to each terminal, so there will be 3 wires at one terminal and 3 wires at another. There will be two legs of 120 feeding each leg of the dimmer (L1 and L3, skipping L2). I cannot suggest a wire size, because wiring sizing is based upon how long your power run is. If you are looking for some portable packs for little shows check out some tree mounted dimmer packs, they will make life much easier. You just have to remember you will be pulling about 60 amps per leg, so amperage will add up fast.
     
  9. Anonymous067

    Anonymous067 BANNED USER

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    Yep. I know the difference, I just didn't understand the documentation at first. I think I get it now...still pondering what size wire or circuit to run.

    My thought, main panel is 200amps.
    I want to pull a 200 foot extention from the main panel to a subpanel (thinking 80-100 amps on the extention). My question comes at what size circuit to run from the subpanel to the dimmer. 60? Ouch.....
    Three 60 amp breakers is going to hurt.

    Anyways thanks so far, any more advice let me know.
     
  10. TimMiller

    TimMiller Well-Known Member

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    its going to be 60 amps per leg. So you will need either 6 60 amp single pole breakers or 3 60 amp 2 pole breakers. I would use a minimum of 6 awg, just you are going to be losing about 5 volts, so I'd personally go with at least 4 awg. For the feeder i'd go with 2/0, just because of the distance. (I am using an electrical calculator to calculate the loads, am I no is CB responsible for any advice given or taken on here). If in doubt contact a qualified electrican. (and now the software disclamer) The Author cannot and does not warrant that any functions contained
    in the Software will meet your requirements, or that its operations
    will be error free. The entire risk as to the Software performance
    or quality, or both, is solely with the user and not the Author.
    You assume responsibility for the selection of the component to
    achieve your intended results, and for the installation, use, and
    results obtained from the Software.

    The Author makes no warranty, either implied or expressed, including
    without limitation any warranty with respect to this Software
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    here, its quality, performance, or fitness for a particular purpose.
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    or indirect, incidental, special, or consequential arising out the use
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    All other warranties of any kind, either express or implied,
    including but not limited to the implied warranties of
    merchantability and fitness for a particular purpose, are expressly
    excluded.
     
  11. Anonymous067

    Anonymous067 BANNED USER

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    So I started crunching numbers today.
    6 120 volt 60 amp circuits (or 3 240's) means 180 amps. Does this mean I need to pull 180 right from my main panel? This isn't really an option. Not to mention starting to get a little outta my "comfortable" or "ethical" range.

    I also starting looking at fixtures.
    575 watt/115 volt circuits.
    thats five amps a light.

    five amps X 12 lights per dimmer is 60 amps per dimmer total.
    But if I have two 60 amp legs in each dimmer....confusion.

    Now 60 amps per dimmer (regardless of circuits) X 3 dimmers is 180 amps.
    Plus I wanted to run 4 seperate 20 amps for sound and stage power...
    And I need another 20 amp for my two movers.

    Umm..way over my "100 amp extention", and I'm probably over my 200 amp house power....

    What do I do now? Bring in generators?
    What kind of power output do they give?
     
  12. JD

    JD Well-Known Member

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    (Insert usual disclaimer here.)

    OK, if you were to feed all your dimmers at full capacity: (6 x 60amp)
    One leg = 360 amps
    Two legs = 180 amps (if balanced)
    Three legs = 120 amps (if balanced)

    If you intended to load your dimmers at half their capacity, and use distribution breakers that were in line with that: (6 x 30amp)
    One leg = 180 amps
    Two legs = 90 amps (if balanced)
    Three legs = 60 amps (if balanced)

    The above figures assume max load conditions (all lights on.)
    Is your house power single phase (two legs) or three phase? What else is loaded on the panel? (pre-existing equipment)

    Keep in mind that your neutral should be up-gauged to handle neutral over-current on a three phase system.
     
  13. Anonymous067

    Anonymous067 BANNED USER

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    I only intend to load at half capacity. So I'll go with the whole 6-30 amps.
    House power is Single Phase, also running in ground pool equipment, pool house, and all the things of the house. AC, Range, Sump Pump (I'm just listing the large breakers in my box).

    Anything else?

    Still wondering bout the generator option.
     
  14. TimMiller

    TimMiller Well-Known Member

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    It depends on the size of generator you are buying. I have a 5kw runs about $600+ at home depot (will run 4 1000W par cans). Then I am in the process of picking up a used 50kw for around $10k and a 60kw for around $15k. To calculate kw into amperage you take your watts 5kw=5000watts, divide it by voltage, then you get your amperage. So
    5000watts/120volts= 41.6amps
     
  15. Van

    Van CBMod CB Mods Premium Member

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    Then pull ten percent off for a safety factor.
     
  16. TimMiller

    TimMiller Well-Known Member

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    Yep, i forgot to put in that part.
     

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