Control/Dimming New Black Box Theater - Need Power Advice.

[spotlightondance]

Howdy,

We're adding a multi-use Dance Studio / Black Box Theater to our Dance Studio facility.

The building owner is putting 200A 3-phase power dedicated for this room, 60A of which will be spoken for by the new HVAC system. By my reckkoning, that leaves 140A remaining for potential Lighting system use. All other service in the building is done through a seperate single phase panel so there's no potential other use for the 3-phase.

The performing / studio space is pretty small, about 1500 sq. ft. and when doing performances in there, we'd expect the area needing lighting to be no bigger than 20' X 30'.

Preface - We will be talking to a lighting supply house / electricians about this but I'd like to have some idea what I'm talking about.

First question - Is 140 A 3-Phase service going to be enough?

Second question - Any recommendations for best practice on interfacing the panel to dimmers? Cam Lok? Direct?

Third question - What 's the most cost effective approach for dimmers? Wall mount, rack mount, portable?

Last Question - Any specific recommendations for dimmer brands for something like this?

Thanks in advance!

 

[coldnorth57]

One more question how long do you plan to stry in this space and are you going to do any show in other venues?

 

[spotlightondance]

1) We will be in the space at least 9 years.

2) We do have annual recitals in two different venues. One of which our lighting guy has to rent a couple of dimmer paks, perhaps 12 channels total, to augment the house system. Not sure what type they are however.

Also, I was just corrected, the HVAC system only draws 40A. Leaving 160 available.

Thanks!

 

[fredthe]

When considering permanent vs. portable dimmers, another consideration will be the wiring from the instruments to the dimmers. Will the space have a lighting grid of some sort? Will there be permanent dimmer outlets on the grid? Or, are you expecting to run single or multi cable from the dimmers to the lights.

I would expect your installation costs to be higher for fixed dimmers, but your equipment/cable costs to be higher for portable.... but this is just a SWAG.

Also, will houselights be on the same dimmers/feed?

Will power for sound come from the single-phase panel?

Are you planning any non-dim power for accessories (scrollers, etc) or moving lights?

Make sure you accounting for everything that would be fed form this service... I could easily see you only having 100A-120A (per phase) to feed your dimmers.

-Fred

 

[Grog12]

Second question - Any recommendations for best practice on interfacing the panel to dimmers? Cam Lok? Direct?

ToS limits us from giving you an answer to this question. Honestly if you have to ask it, then you're probably not qualified to be interfacing your dimmers with the panel.

All in all it will depend on whether you do portable or permanant dimers.

My firm suggestion consult a qualifed eletrician in your area.

 

[fredthe]

My firm suggestion consult a qualifed eletrician in your area.

I think you're being a bit harsh... he already said he's going to be talking to electricians, he just want's to be sure he's asking the right questions. Many electricians won't have a clue what a company switch is.

It should be pointed out that if they are going with protable dimmers, they will need someone qualified to connect/disconnect the dimmers from the service.

-Fred

 

[TupeloTechie]

I think you're being a bit harsh...

Welcome to ControlBooth...

 

[Grog12]

I think you're being a bit harsh... he already said he's going to be talking to electricians, he just want's to be sure he's asking the right questions. Many electricians won't have a clue what a company switch is.

It should be pointed out that if they are going with protable dimmers, they will need someone qualified to connect/disconnect the dimmers from the service.

-Fred

In situations dealing with electricity, especially when it comes to doing "tie-ins" I'd rather be a bit harsh and safe, than not.

Yes, the OP said he was going to talk to both his supplier and a qualified proffesional, but there are certain things our TOS limits.

This is one of them.

Also, let me clarify what I'm trying to avoid here: The OP asked about best practices for interfacing dimmers using cam's and direct tie-ins. I'm trying to avoid discusion about how to use either while installing the racks. Best practices usually means "how to" when you're setting up a system. Such as it's the best practice to hang a light right side up.

 

[gafftaper]

Yeah sadly we can't talk about specific tie in details, but a professional theater electrician will be able to set it all up for you.

I believe you said you are in Vermont. Do you need help locating a dealer?

There are so many variables it's hard to suggest permanent vs. portable. I suggest you get a dealer in there to give you some price quotes on options.

Do you need more power? If you plan more than just a primitive system YES. A standard single dimmer these days is 2,400 watts/110V= 20 amps. My black box theater has 196 dimmers... so yeah I use a little more than 140 amps. I helped setup a dance studio a few years ago they installed FOUR- 12 channels x2,400 watt dimmer packs... at about 250 amps each if my math is correct. That was about right for a nice sized dance studio

As far as brands of both dimmers and light control boards. ETC (Electronic Theater Controls) set's the bar high in product quality and service. Strand products are not far behind (depending on who you talk to). Some of the other manufacturers out there are a solid choice some are not. Do you best to get an ETC or Strand system. If you get price quotes on something else check back with us to see what we think of the brand.

Another interesting option would to consider would be going with no dimmers. Just distribute non-dimmed power all over the place and go with all LED's and non-dimmed moving lights. It would be very interesting to discuss pricing on this strategy with a dealer. SOMEDAY that's the way all new theaters will be built. You can use far less power this way, the building will be cooler (lower cost on HVAC)... lots of positives. It might be a little higher priced initially than going the traditional route but if you have the money the long term benefits of going all LED might be worth it. You also are putting all your money into fixtures that you can take with you to another space if you need to move. Going all LED would also mean you could easily get away with not upgrading your 140 amps.

Tell us more about what you do in the space. What are your expectations for the lighting system? What is your budget? How large is it. Again is there a lighting grid already installed or are you doing that at this time too? What do you plan to use to control the lights?

Pictures could be helpful.

 

[derekleffew]

...Do you need more power? If you plan more than just a primitive system YES. A standard single dimmer these days is 2,400 watts/110V= 20 amps. My black box theater has 196 dimmers... so yeah I use a little more than 140 amps. I helped setup a dance studio a few years ago they installed FOUR- 12 channels x2,400 watt dimmer packs... at about 250 amps each if my math is correct. That was about right for a nice sized dance studio. ...

The quantity and capacity of the dimmers does not determine the supply. The connected load determines the supply. See Dimmer feeds--How much power is enough?. Given a 140A/leg 120/208V 3Ø Wye-Connected 4W+G service, a maximum of Eighty-Seven 575w fixtures could be connected. That sounds adequate for a performance area of 20'x30', in a 1500 sq. ft. venue.

First question - Is 140 A 3-Phase service going to be enough?

In all probability, yes. Unless you're planning on presenting the American Ballet Theatre.

Second question - Any recommendations for best practice on interfacing the panel to dimmers? Cam Lok? Direct?

Depends on the answer to #3.

Third question - What's the most cost effective approach for dimmers? Wall mount, rack mount, portable?

Since you're likely talking about 24-48 dimmers/circuits, a wall mount rack is probably the most cost-effective. Install equipment is cheaper than portable, but is offset somewhat by installation labor costs.

Last Question - Any specific recommendations for dimmer brands for something like this?

ETC, Strand, and Leviton are the top tier. Second tier includes EDI, Teatronics, ET, Leprecon, Lehigh.

Questions for you:
Have you chosen a console?
Do you have an existing inventory of fixtures?
Who will be "doing lights" (professional, volunteer, janitor)?
Will the houselight system be separate from the stage light system?
Do you have an architect or someone who will check your plans for code compliance?
Notice how the questions keep getting longer--have you considered engaging a theatre consultant?

 

[Van]

...--have you considered engaging a theatre consultant?

I've considered strangling several, over the years.

Having a couple of small black boxes myself I can tell you the idea of a small to medium sized rack mount < permanent> system and the installation of a company switch for touring groups to tie-into, "tis a consumption devoutly to be wished."

 

[spotlightondance]

Appreciate the comment about the ABT. Actually, the Artistic Director of the ABT has been in our space before. He's the brother of one of our employees.

Great discussion, very helpful in clarifying exactly how much I don't know about this stuff.

Have you chosen a console?

No.

Do you have an existing inventory of fixtures?

No


Who will be "doing lights" (professional, volunteer, janitor)?

Sometimes Pro, sometimes me.

Will the houselight system be separate from the stage light system?

Yes, all other service in the room is from another panel.


Do you have an architect or someone who will check your plans for code compliance?

Yes

 

[mstaylor]

Make sure when you consult an electrician that he has knowledge of both theatrical electricity and local codes. If this not possible the youwill need two electricians. Believe me, I had a huge problem with a lighting company that had no business selling anything and an electrician that had no clue and no desire to understand theatrical lighting.

 

[Van]

Make sure when you consult an electrician that he has knowledge of both theatrical electricity and local codes. If this not possible the youwill need two electricians. Believe me, I had a huge problem with a lighting company that had no business selling anything and an electrician that had no clue and no desire to understand theatrical lighting.

A fellow technician of mine once went to a Theatre to do the engineering check-off and system initial power on, only to find the electrical contractor who had installed the outlet races had installed common neutrals
a project that was already a week late, got even later...

 

[gafftaper]

The quantity and capacity of the dimmers does not determine the supply. The connected load determines the supply. See Dimmer feeds--How much power is enough?. Given a 140A/leg 120/208V 3Ø Wye-Connected 4W+G service, a maximum of Eighty-Seven 575w fixtures could be connected. That sounds adequate for a performance area of 20'x30', in a 1500 sq. ft. venue.

My Bad... forgot the 208V in the equation. While yes you can power Eighty-Seven 575w fixtures. In order to get that many fixtures you will have to gang them together 3 or 4 on the same circuit. That's not a terrible thing, but it does mean you will not have a lot of independent control of fixtures if you stay with only 140A.

No one has commented on my idea of ditching the dimmers and going all LED's and Movers. If you don't spend thousands of dollars on Dimmers and Raceways you have a lot of money left to buy LED toys. We have a tiny stage we are going to put into the new student union at the college (about 12x8). We are going to skip the dimmers and just install a dozen 1' Seladors. No need for dimmers, no need for raceways, an electrician can run a couple standard circuits and I've got all the power I need. It's cooler. Lots of color flexibility. True you can;t use a gobo, but that's not a problem in simple setups. In the case of the dance studio mix in a couple of movers to go with the LED wash and you get your texture as well.

 

[fredthe]

No one has commented on my idea of ditching the dimmers and going all LED's and Movers.

OK, I'll comment... I think it's an excellent idea, and definatly worth investigating. In fact, I wish I had thought of it when reviewing the specs for addition of a small lighting setup to a theater classroom (with a small stage area) last year. It would have been perfect.

The question is, with today's technology, how small does the space need to be for this to be effective?

Another approach (borrowing on a couple of your ideas ) would be to do LEDs, plus 1 or 2 2400W 6-packs and a few conventional fixtures (with perhaps Scrollers, iQues, etc.) instead of moving lights for patterns and specials.

-Fred

 

[Footer]

Inrush current. When a motor starts, it takes more power then it takes when it runs. You don't really have 140 amps. Some motors take 3x as much power to start up. So, if the contractor is installing 30amps of motors it could easily take 80 to 90 amps to start the system up. I don't think you have enough power to do what you want to do unless they are already factoring in the inrush. Granted they usually do staged startups, but it is still a consideration.

Ask the contractor/engineer about this. It would be bad if you loaded up to your theoretical 140amps and the AC kicks on and you blow the panel. Most places do not understand how much power it actually takes to light a show so they will gang up things like HVAC on the same panel.

 

[mstaylor]

One solution to the start-up problem for the AC is to use a rampup coil to start the equipment. It keeps from pulling so much power and if you have the bag type ducts that are becoming popular it keeps from filling so fast that they scare the audience.

 

[mrb]

(I skimmed over the thread and didnt notice mention of this, sorry if someone else already pointed it out)

You need to double check what this 200a 3ph service is. It is not common for a building to have both a 120/240 single phase, and a 120/208Y three phase service. It is very possible your 3ph service is 240 delta which would require a 240D-208Y120 transformer to be able to supply dimmers.

 

[derekleffew]

...While yes you can power Eighty-Seven 575w fixtures. In order to get that many fixtures you will have to gang them together 3 or 4 on the same circuit. That's not a terrible thing, but it does mean you will not have a lot of independent control of fixtures if you stay with only 140A. ...

Because independent control of fixtures requires more power than 3 or 4 on the same circuit? Lighting dance is generally about broad strokes and washes, not finicky specials shuttered with hairline precision.

...No one has commented on my idea of ditching the dimmers and going all LED's and Movers. ... In the case of the dance studio mix in a couple of movers to go with the LED wash and you get your texture as well.

I wouldn't want to light any stage solely with soft-edged LED fixtures, especially dance. Advocating moving lights for a less than fully professionally-staffed facility seems contrary to the Gafftaper Method, doesn't it?