New Fixture AC Power

[LPdan]

Question regarding AC power for new fixtures being installed for a renovation (LED, movers, etc).
Is it typical to supply circuits from breakers/disconnect located back stage? Or should all new circuits go through a relay module in a dimmer rack? Are there different answers based on venue type?
I understand if a previous dimmer circuit is being converted, it would make sense to use a relay module. But if new lines are being run, what is best practice?

 

[Les]

If new lines are being run, the best solution (in my opinion) is something like the ETC Echo panel. The relays can be set up for DMX control, so you can Park them at the console, only use them when needed, etc. A backstage disconnect, while it would work, would require someone either flipping breakers every night or leaving fixtures on 24/7. Neither of which are ideal, of course.

 

[JD]

Running through relay modules (the type that go "click" because they have a mechanical relay in them) is your best bet. I like this idea over a large contactor feeding a branch panel because you actually don't want all your relays to go "click" at the same time. Inrush is high on fixtures that use power supplies (all modern LED fixtures) and even if the system can handle it, you can still generate some pretty good line noise. Best to have a scene that brings them all alive in a sequence with each circuit 5 seconds after the prior one.

 

[LPdan]

Thanks guys, this is what I suspected. but appreciate the confirmation.

 

[SteveB]

Question regarding AC power for new fixtures being installed for a renovation (LED, movers, etc).
Is it typical to supply circuits from breakers/disconnect located back stage? Or should all new circuits go through a relay module in a dimmer rack? Are there different answers based on venue type?
I understand if a previous dimmer circuit is being converted, it would make sense to use a relay module. But if new lines are being run, what is best practice?

New install ?, DMX controlled motorized circuit breakers might be the most cost effective. A big issue is if you are using fixtures needing 208v, you can do 2 pole with a MBP. You can only do 120v with a dimmer rack. Note though that the trend is towards smaller yet brighter fixtures that tend to use less power. Unless it’s a big facility with long throws for the fixtures.

The most flexible and if only needing 120v to branch circuits would be an ETC Sensor rack using ThruPower dimmer/relay modules. You get either dimmed or switched as per need.

 

[BillConnerFASTC]

I've been putting in Sensor IQ panels where all LED. Coupled with Paradigm a of features. If conventional dimming is required or desired, it gets more case particular. All sensor and through power modules gets very pricey. A lot more detail to study.

 

[LPdan]

I didn't realize you couldn't get a 2-pole 208V relay module in a Sensor rack. Doesn't seem technically difficult, any idea why?

 

[sk8rsdad]

There are only 2 physical locations in the rack where two phases are adjacent and any module that could potentially make use of that would have to use up 2 module slots.

 

[BillConnerFASTC]

Sensor IQ does two and three pole to 30 amps.

 

[sk8rsdad]

Sensor IQ is an "intelligent" breaker panel which is a completely different beast than a Sensor dimmer.

 

[BillConnerFASTC]

Sensor IQ is an "intelligent" breaker panel which is a completely different beast than a Sensor dimmer.

I'm quite aware of that but op said

Is it typical to supply circuits from breakers/disconnect located back stage?

so I suggest a separate relay panel.

 

[Chris Pflieger]

If there's architectural lighting control, and it's integrated into the theatrical control, then you could run your circuits through its relay panel or distributed relays.

 

[SteveB]

If there's architectural lighting control, and it's integrated into the theatrical control, then you could run your circuits through its relay panel or distributed relays.

Ours is set up so that the Paradigm system “can” power up key circuits, OR they can be energized via the Ion. It’s all DMX so whatever control is best. Our audio stuff is on Paradigm so the buzz heads can play without needing an adult to power the Ion

 

[BillConnerFASTC]

Controlling relays - I have on and off on a passworded screen on Paradigm, but also use to turn them on when any button was pushed, turn off at 2 or 3 am. Now I put occupancy/vacancy detectors at each entrance and usually a couple over proscenium and do same programming. I got tired of watching multiple stabs of entry panels as there is a very slight delay between button push and relays powering. I hope the detectors give it enough of a jump so first button push turn on lights. Will also turn on down light in sound and light lock so maybe they don't have to push a button till in auditorium or stage.

 

[SteveB]

Controlling relays - I have on and off on a passworded screen on Paradigm, but also use to turn them on when any button was pushed, turn off at 2 or 3 am. Now I put occupancy/vacancy detectors at each entrance and usually a couple over proscenium and do same programming. I got tired of watching multiple stabs of entry panels as there is a very slight delay between button push and relays powering. I hope the detectors give it enough of a jump so first button push turn on lights. Will also turn on down light in sound and light lock so maybe they don't have to push a button till in auditorium or stage.

Funny story of a co-worker who was the first TD for a new PAC co-located at a high school. The main auditorium entrance from the school had a Paradigm single button tucked away off the door that activated some of the lighting. It also had about a 3-4 second delay with my buddy subsequently learning to walk in to the dark room, hit the button, than call out loudly "Lights ON !". and Voila, the lights turned on. Turns out the principal never really noticed the button and spent a year trying various methods of saying "Lights on", or "LIGHTS on", or LIGHTS ON ! ! !" to no avail. Then he would have to go find the student whose voice was recognized by the system and who knew about the secret button. The student subsequently graduated and hating the principal, never told him about the button. They had to call ETC and get a service call, with a tech. who had no idea what they were talking about with the "voice activated system" and proceeded to show them the secret button.

 

[teqniqal]

Another resource for DMX controlled circuit breaker panels is LynTec (www.LynTec.com). Available in single-phase or three-phase panels. If you can get a single-phase feed this is better for mitigating harmonics generated by all the solid state lighting power supplies (and phase control dimming, too). The audio and video guys have figured this out long ago, so by designing single-phase distribution in lieu of three-phase distribution, you can reduce the electrical noise envelope for them by killing the harmonic problems before they back-infect the A/V systems.

 

[STEVETERRY]

Another resource for DMX controlled circuit breaker panels is LynTec (www.LynTec.com). Available in single-phase or three-phase panels. If you can get a single-phase feed this is better for mitigating harmonics generated by all the solid state lighting power supplies (and phase control dimming, too). The audio and video guys have figured this out long ago, so by designing single-phase distribution in lieu of three-phase distribution, you can reduce the electrical noise envelope for them by killing the harmonic problems before they back-infect the A/V systems.

Erich, I believe you may be referring to "balanced Power " specifically operating at 120V line-to-line, and 60V to ground. This is not simply single-phase power, but a separately derived system where a 120V secondary has a grounded center tap. It is covered by NEC article 647-- Sensitive Electronic Equipment.

Since both ungrounded conductors of the circuit are 60V above ground, it comes with some Code-mandated caveats:

1. All 15A and 20A outlets must be GFCI protected.
2. All breakers must be two-pole.
3. Any lighting equipment connected to the system must have a means of disconnect that opens both ungrounded conductors. This disconnect must be lockable and within sight of the luminaire it feeds.
4. Outlets must be marked as follows:

WARNING — TECHNICAL POWER
Do not connect to lighting equipment.
For electronic equipment use only.
60/120 V. 1φac
GFCI protected

5. There are stringent voltage drop requirements for permanent circuits to insure that there is sufficient fault current at 60V to ground to trip OCPD's on a ground fault.

Article 647 has additional requirements that are worth reading (like how to install a 3-phase version), but I've left them out for brevity. While this type of power works to improve ground loops as a source of noise, it does not come "free", as noted above.

For more on balanced power, see this link from the guys that thought it up:
http://www.equitech.com/articles/bpng.html


Cheers

ST

 

[Chris Pflieger]

Another resource for DMX controlled circuit breaker panels is LynTec (www.LynTec.com). Available in single-phase or three-phase panels. If you can get a single-phase feed this is better for mitigating harmonics generated by all the solid state lighting power supplies (and phase control dimming, too). The audio and video guys have figured this out long ago, so by designing single-phase distribution in lieu of three-phase distribution, you can reduce the electrical noise envelope for them by killing the harmonic problems before they back-infect the A/V systems.

Their stuff looks good, but if you want any switch status, it appears you're limited to simple dry contact switches, no?

 

[macsound]

It becomes more of an overlap in my mind when "conventionals", moving lights, networking gear and audio could potentially/accidentally share power, especially in a less controlled situation like a school.
I've worked in plenty of facilities where all non-dims were only circuit breakers and it was only the circuits for moving lights that were turned off at night.
Also my fair share of locations where lighting had worklights and show non-dim relays on a single panel backstage. Made it confusing because if someone forgot to turn off the motion lockout, then the next day when someone came in, there was no light except for the ghost light.
Is there a best case setup now that things like "my plug doesn't fit" is no longer the way you prevent the inexperienced from plugging something into the wrong hole?

 

[BillConnerFASTC]

Macsound - not understanding your concern. AV should be on a separate panel from lighting. Let everything turn off as I suggest above - sweep at 1:00 am or whatever. Use occupancy/vacancy detectors to turn on something - passage light at least - as someone enters and all relays are off. Passworded override available.