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Late Night Rant, INFO FOR EVERYONE WHO USES MOVERS!!!!!!!

Discussion in 'Lighting and Electrics' started by TimMiller, Jan 29, 2008.

  1. TimMiller

    TimMiller Well-Known Member

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    DO NOT PLUG MOVERS INTO DIMMERS!!!! WITHOUT USING A TRUE NON DIM OR RELAY MODULE. JUST PUTTING A DIMMER ON "NON DIM" DOES NOT MAKE IT A NON DIM CIRCUIT SAFE FOR A MOVER. YOU END UP FRYING THE POWER SUPPLY!!!!

    I just got a rig back from a school who kindly plugged everything into their dimmer rack and just put the modules on "non dim" and did not install true non dim modules. Needless to say x-spot and studio beam power supplies are not cheap at all!!!!


    RANT OFF

    If anyone is wondering the real scientific reason why just ask. It will be my next rant :)
     
  2. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    Why thank you for that rant, TimMiller. Reminds me I keep forgetting to ask [user]Gafftaper[/user] if he has any extra relay or constant power modules for his new C21 racks. Or how he's planning on powering all his little gadgets. And if he has a 3Ø (Is it ø or Ø? Which is more correct?) 120/208VAC, Wye-connected, 5wire, company switch, even a little 200amp one.

    I didn't even know one could run Xspots and StudioBeams from 120V. Are they voltage auto-sensing, or do you have to change jumpers or fuses or anything?

    Not on my dimmer racks you don't.
    Into the wall, or not at all!

     
    Last edited: Jan 29, 2008
  3. TimMiller

    TimMiller Well-Known Member

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    x-spots and studio beams will run at 120V no problem. They have auto switching powersupplies, so you can plug them into anything between 110-230
     
  4. len

    len Well-Known Member

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    I always thot they were 208V only. But the last time I used an X-spot was 5 years ago. No one around here owns them any longer because customers always spec out Mac2K

    As for replacing the power supplies, that's customer error. Anyone who rents a fixture like that should know better. Bill your customer for them.
     
  5. icewolf08

    icewolf08 CBMod CB Mods

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    There is only one fixture that I know of that which in it's manual says that you can run them on a dimer in "Switched" or non-dim mode, and that is the ETC Source Four Revolution. Other than that, running most electronics on a dimmer can mess up the electronics, so I keep a bunch of relay and constant circuit modules.

    What I would really love is if ETC released a half non-dim, half dimmer module so that I didn't loose two dimmers ever time I want a non dim in the rack.
     
  6. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    Yes, but wouldn't you then need "right hand" and "left hand" modules, and you'd invariably run out of the wrong type. You have ETC dimmers and Strand consoles? Best of both worlds?
     
  7. TimMiller

    TimMiller Well-Known Member

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    Just being able to run off a dimmer in non dim mode doesnt make up for how much a source four revolution is a piece of crap. I'll take an x-spot any day over a source four revolution, heck i'll take an american dj fixture over a source four revoultion, at least they will go back to their proper position and have dicroic colors.
     
  8. JD

    JD Well-Known Member

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    Movers, strobes, or anything with a power supply should not be run off a dimmer. As this issue has come up before, I must admit I am somewhat perplexed as to why movers would need to be connected to anything even near a dimmer pack.

    I guess I live in a world where movers have their own distro. (road shows, etc) So what is different in the theater? Is it the need to be able to shut everything off at the end of the night from the board?

    With most stage lights using stage pin connectors, and most movers being equipped with Edison, the two worlds seam self isolating. I am making the assumption that many convert the movers to stage pin connectors and have some form of patch bay where they are assigned.

    It would seam logical in a fixed location to have a large contactor (relay) installed that fed the mover distro, and either fire the coil off of a dimmer (see note below) or use a low voltage remote controlled from the booth if the convenience is desired.

    For me, simply turning off the distro as part of the end-of-night routine works fine.

    Note: Most dimmers do not like relay coils or loads under 15 watts, and would need some phantom load, such as an indicator light.
     
  9. TimMiller

    TimMiller Well-Known Member

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    I thought it would be cool if the dimmer modules had a relay in them, so when you set them to non dim, the electronics in the rack would activate a relay and bypass the SCR, making it a true non dim circuit. Or even if they just had a non dim switch that would bypass the SCR and route power straight through. I have made dimmer modules into true non dim modules before, by gutting out the SCR's and Chokes.
     
  10. soundlight

    soundlight Well-Known Member

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    If anyone on here has a computer oscilloscope, could you test wall power vs. non-dimmed dimmer circuit and post screenshots of the actual waveform? I know that it's very detrimental to put MLs on a "switched" dimmer, and I never do it, but I wanted to know what the difference actually looks like.
     
  11. JD

    JD Well-Known Member

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    I could probably draw it from memory as I used to service them. Basically, an SCR or Triac will not turn on until there is forward voltage across it. Therefore, even at 100%, they do not turn on at the very start of the waveform. The ramp/trigger/control circuit is designed to allow a rise of about 15 to 20 volts before firing when in the "full on" mode. As the peak (not RMS) of the AC waveform is over 200 volts, the missing front of the waveform becomes insignificant and looks much like a tiny missing pie piece on the scope. The general "pass" rating of such a dimmer is usually 98% (Less what is lost in the choke.) Remember, we are not talking about subtracting 15 to 20 volts, we are talking about subtracting several milliseconds of the front end switch on the half-wave. (Same pattern is repeated on the opposite half-wave as well.)

    What this does produce that is so detrimental to power supplies is a "front wall" to the waveform. This front wall has much the same harmonic effect on inducting components as a square wave does, so magnetic ballasts are out of the question. Transformers (post dimmer) are also a bit of a problem, but if the secondary is under a good resistive load, they will work. I should add that I would not recommend connecting ANYTHING inductive to a dimmer due to the flyback voltage effect.

    Bottom line, even in non-dim mode the SCR / Triac type dimmers require the same physics to operate and should be considered to be a dimmer. One other note, Solid State Relays should be considered the same as that's what's in them! The only non-dim module that could be used would be one that uses a mechanical relay to make or break the circuit.
     
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  12. icewolf08

    icewolf08 CBMod CB Mods

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    Dimmers were a new install before last season. Due to our relationship with ETC (Karl Haas being one of our designers) we got a great deal on new Sensor+ racks. The strand consoles are still functioning fine, and when Strand discontinues support for them in 2010 we will probably upgrade (to what, I am not sure yet).

    Not that we need to have this discussion, but the Revolution does what it is supposed to do really well. It is a theatrical fixture, it isn't designed for flash and trash. With the choices for affordable and useful Tungsten/halogen fixtures at basically either a VL1000 or Revolution, it isn't a bad choice. It has a lot more ups than just being about to be connected to a dimmer.

    The difference comes especially in houses that have dedicated raceways and dimmer-per-circuit systems. If you are hanging a ML on a lineset with a dedicated raceway, it is a lot easier to just connect to a circuit that is right there and toss in a non dim/relay card as opposed to running extra cable up from a distro. I have worked in theatres that run power up, but that was because all their MLs were 208v.

    As for the connector issue, most fixtures come with bare tails, at least in my experience. If you buy a MAC2K, they don't know if you are going to run it on 208v and use an L6-20 or if you are going to run it on 120v and use edison. Sure, if you buy an AMDJ fixture you will probably get something with either and IEC or powercon to moulded edison, but the users of those fixtures only use edison. Connectors really don't separate anything.
     
  13. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    In my world almost everything not on a dimmer, and the last 3 shows have not had any dimmers, use L6-20, and run at 208V. Unless the show is by that R&R company with all the big red trucks--they like the L6-15. I have had one company use 2P&G on all their movers at 208V, that's just begging for trouble!
     
  14. tgates

    tgates Member

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    I've seen that too, and it blows my mind. Then again, it also gets me how many people run their soco as 6 208 lines. I had one company that had 6 movers on a 208 soco, and 6 movers on a 110 soco. If that isn't asking for trouble I don't know what is.
     
  15. TimMiller

    TimMiller Well-Known Member

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    Running 6 movers at 208 on a soco isnt a problem. Its not any different than running 6 120V movers on a soco. The "neutral" which is separate for every circuit carries your second leg, just like the blue wire is normally used for neutral in moving lights carries the second leg. Then you have your grounds which of course remains ground to keep everything happy.
    You just have to be sure that your system tech (usually my job :) ) knows what they are doing and labels everything properly. I label everything but on top of that, we use 14 awg soco to run to the par bars and 12 awg to the movers so you can also tell by the thickness of the wire. BUT THIS METHOD DOES NOT SUBSITUTE LABELING!!!!! LABEL LABEL LABEL!!!!!!
    There are audio companys that also use soco to feed to their speakers, so you need to be sure to LABEL!!!! I have had numerious people cuss at me when i tell them to take apart everything because they did not label. Now all of our guys are anal about labeling. Top drawer of our road box is white gaff and a sharpie. I also started laying everything out on a plot, so i know exactly what movers are connected to exacly what breaker in the PD.
     
  16. JD

    JD Well-Known Member

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    I see how a raceway DPC layout would be a big problem. You would almost have to use blank modules that only have a breaker on them. I would think that even relay modules would have the drawback that a blackout cue would cause the ML's to drop arc which would be a real pain! (most dimmer systems use a threshold on/off) Funny, I would think non-dims should take a cue from the lamp off/on systems that movers use (3 seconds at a certain value.) Maybe some already have and I am not aware of them.

    On the bright side, I suspect in a few years, when all dimmers are IGBT* driven, it will no longer be an issue as IGBTs do not require any front-end drop voltage when fully gated to operate in full on mode, giving them the same output as a relay in non-dim mode. I have not looked at the waveform from any reverse-phase IGBT dimmers yet, but they may already be achieving this.

    * The "Insulated Gate Bipolar Transistor" is currently used in Sine Wave and Reverse Phase dimmers as it can be turned "off" as well as "on" during the AC waveform. Currently, IGBT dimmers are far more expensive than SCR dimmers. In my opinion, this will change although I am sure "marketing and sales" will work hard to preserve the price. Bottom line is that silicon is cheaper than copper, an the elimination of that large copper wad called a choke makes IGBT dimmers cheaper to manufacture.
     
  17. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    In Las Vegas, the undocumented RULE is 208V Soca's are marked with red or pink tape, and conv. mults are marked with Black sharpie on White tape, or white paint pen on Black tape.

    Except for one very good master electrician who can't stand seeing red or pink tape in the truss on Ballroom gigs--she insists on Gray tape for 208V and White pen on Black tape for dimmer circuits. Also the yellow e-tape is only and always used for spare circuits in the breakouts or on the DMX lines.

    Good standards, too bad no one can agree. And of course the PRG S400 system totally solves the problem of plugging a conv. mult into 208 and blowing all the lamps. If the power source does not match the breakout box, it won't pass power--what a novel idea!

    Two ways of solving this, depending on the console/preferred practice. First, the relay/non-dimmer can be profiled either "Full at 1%", or "Always FULL" even if it's a relay. And/Or, The "power" channels are parked at FULL via a macro first thing in the day, and unparked last thing at night. Or the channels are set on the CEM(s) but I don't recommend that one.
     
  18. soundlight

    soundlight Well-Known Member

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    I always use Macros. We have a startup macro which parks the ML relays and also runs all of the MLs to their extremes to calibrate them (our old Intellabeams usually need re-calibration via extremes on startup.
     
  19. SteveB

    SteveB Well-Known Member

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    What a funny co-incidence. My last event, the much complained about version of The Tempest, travelled with 2 Auto-Yokes placed on our #1 Electric (raceway and DPC system), to which I popped in a dual relay module to power the AY's.

    I do this on occasion and never have issues. It's my house, my assistants all know what we are doing and why.

    On this occasion, desiring to Park the relays ON for the AY's meant remembering to NOT hit "Dimmers Release Enter- Enter" while in Park on an Express 250. I wanted to Snapshot them in my Unison, but the LD wanted control.

    I also keep my 5 Studio Spots wired with 2P&G connectors. This is not accepted practice but it's in-house and EVERYTHING is labeled to hell and back as "Moving Lights - do not plug direct to dimmers". Having 2P&G allows me to use standard stage cable to move the fixtures around as required, But as Tim put it "Label It !". And tell everyone from the cleaners to the GM what you are doing and why.

    BTW, Parked dims and channels on Express/ion do not respond to Blackout or Grand Master.

    Steve B.
     
  20. icewolf08

    icewolf08 CBMod CB Mods

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    I use independent subs to attack this issue. Run faders up preshow, and they will stay up the entire time. The get recorded into all the cues during tech, so even if I were to forget to run up the faders, the channels come up in my preshow cue and track through the show.
     

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