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[Luke Richison]

My church bought an old strip mall and gutted it. We've got a (relatively) blank slate to design our stage, which we'd like to be flexible enough to double as a small venue. I've got a pretty good handle on the audio but none at all on powering it. So, I was hoping someone on here could give some advice on what is ideal for a House of Worship / Small Venue (and if this post belongs in that forum).

Here are a few things I'm pondering:

• Should we run a sub panel to the FOH and have dedicated circuits for each element (PA, FOH, Lights, Stage / Instrumetns
• Do we leave the sub panel and run home runs to each element
• Dedicated 60a service instead of sub panel?
• Should we group PA, FOH, and Stage on one larger circuit (20a, 30a?)
• What about a power conditioner or sequencer

I would also appreciate advice on what is practical given our limitations (this is the relatively part of our blank slate):

• powerwed Mackie HDAs and subs for PA
• Presonus StudioLive mixer
• No floor monitors - we use in ear monitors
• No backline - everything goes direct
• LED lighting, and we're considering par cans
• Being a church, the budget is (as always) quite minimal

Thanks in advance

[TJ (Tom) Cornish]

A few non-complete thoughts and suggestions:

Thinking about this now is a good idea.  A sub panel for all audio and video power has some benefit if it shortens the distance between the grounds of the different receptacles in the system, but there's very little noise immunity benefit to separating lighting, unless there's a transformer in-between.  Modern equipment and non-garbage dimmers (and possibly getting rid of single-coil electric guitar pickups) should be all you need to be noise free.

My priorities would be in the following order:
1.  Getting enough power
2.  Getting enough power in the right places - amp room, dimmer room, etc.
3.  Getting modern equipment that doesn't have noise immunity problems
4.  Sourcing all audio and video power from the same panel
5.  Sourcing lighting from a different panel from audio/video

Even if you're going to use a portable PA system now, plan for an install.  Depending on the size of your auditorium, you may want to reserve a few 20A circuits for amplifiers all the way up to a dozen or more in the place your amplifiers will go in the future.

For lighting, LED fixtures for color wash really make a huge difference in usability and power consumption.  In my opinion, white front light is still better done with tungsten fixtures, which take a lot of power.  For larger systems, dimmers are usually done in a monolithic dimmer rack.  For smaller installations, a couple circuits feeding multiple locations of tree-mount or dimmer-bar units is likely more economical.

You can't feed standard receptacles from anything greater than a 20A breaker - multiple circuits is your solution.

Telling us a little more about your space, your plans, and your constraints will help get more relevant and specific advice.

[Kevin Graf]

Before you start,  spend some time and read the following papers:
They total about 145 pages, but it's time well spent.

"Power White Paper" from Middle Atlantic.com
http://www.middleatlantic.com/power.htm

The Bill Whitlock of Jensen Transformers Seminar paper
http://www.jensen-transformers.com/an/generic%20seminar.pdf

The Jim Brown of Audio Systems Group white paper
"Power and Grounding for Audio and Audio/Video Systems"
http://www.audiosystemsgroup.com/SurgeXPowerGround.pdf

[Tom Young]

Kevin's reply contains VERY good sources for how to do this right.

I would add that while you do not use stage monitor wedges and backline now, what happens in the future is a question mark..... even if you think it isn't. You would be wise to place a few 15A-20A ckts around the platform and add a few in your amp rack or where amps would be racked if they are used in the future.

FWIW

[Mike Sokol]

Kevin's reply contains VERY good sources for how to do this right.

Agreed.... So while I'm teaching seminars in Texas this week (and not at my desk) I don't have a lot of time to thing about your questions this week. However, I would suggest that to future proof your system you add at least one "house power" connection. In the old days (before LED lights and Class-D power amps) I would have suggested camlocks and a 200-amp circuit breaker. However, I think it's time to revisit a trick I first used some 40 years ago in my misspent youth at the Old Mill Inn. A 50-amp/240-volt Range Outlet (NEMA 14-50) fed by a double-pole 50-amp circuit breaker in the service panel would allow most any medium size act to plug in their own power distro and run quite a large sound and lighting system. Unless you are doing major shows, then 100 or 200-amp camlocks seem like expensive overkill. But a 50-amp/240-volt range outlet located near the stage would give you a lot of future expansion options since that's 100 amperes of 120-volt power which is sufficient for a 10,000 watt PA system and a pretty large LED lighting system. I'll have to double check with my code monkeys, but this should be perfectly code compliant and WAY more legal than letting a visiting band hang some camlock pigtails out of your open circuit panel.

I would appreciate some input from the other sound pro's here. Does this seem like a reasonable distro power idea for a small/medium church or club, or is it too simple/crazy to work? Of course, really big productions need really big power from camlocks, but how much room do you have on stage for potential acts?

[Tom Bourke]

• Do we leave the sub panel and run home runs to each element
• Dedicated 60a service instead of sub panel?
• Should we group PA, FOH, and Stage on one larger circuit (20a, 30a?)

That is not even CLOSE to enough power to have in reserve.  Admittedly that will cover most normal church productions it leaves you NO room to grow. Here are some reference points:
An Aqua2000 dry ice fogger for  that special Christmas, Rapture, wedding, other big production will eat 2 20A circuits on stage.
That same production may also have a couple of full size moving lights, that's another 20A circuit or two per pair of lights. 
A decent sized amp rack will need two or three legs of 20A to 30A.

Also when sizing an entertainment power system you need to plan for closer to 100% peak power use than a regular house.  During the climax your going to have every light full plus sound rocking.

With out knowing the size of your venue I would want to see a MINIMUM 100A to 200A single phase service for production with plenty of spare room in the breaker panel for expansion or small cams.

As soon as you want to add the option for flying truss it goes to 200A 3 phase minimum. The chain motors will most likely need 3 phase.

Contact a few of the local production companies to come and see your space.  Ask them what power they would need and expect to do a medium to large show in your space.  Then at least prep for that kind of power.  If they want 400A 3phase and you have no intention of ever going that big, at least get an appropriate sized conduit in place so you can pull a feed, put in a camlock disconnect and set a transformer with out breaking into cement to do it.

Edit: Forgot to add that the last theater power upgrade I was in charge of was a 600 seat high-school auditorium.  We had a 400A feed to the main dimming system plus 2 circuits on stage and 2 in the booth that was shared with the "scene shop."  I think we may have had a couple more available in the house.  It was a nightmare.  We would end up running a couple of dimmers in constant on mode to get power for any extras.

We added a 200A 3phase panel with dedicated transformer.  For circuits we added:
8 20A quad boxes near stage floor.
2 L21-20 circuits (3 phase) on 6 connectors in the ceiling for chain motors and breakout stringers for LED's.
7 20A circuits spread threw out the FOH lighting positions for movers and video projectors.
4 circuits in the booth for various needs.
a few more 20A circuits in the scene shop they desperately needed.

It may sound extravagant but ALL our power problems went away!  No more hum from the powered speakers on stage being on a different panel and transformer from the FOH console.  No more rolling ground loop waves in the projectors because now they were all on the same power.  Director wants 2 huge foggers? no problem, I made sure we had 2 locations with plenty of power up stage for foggers.  Flying stuff got much more safe since we could now use chain motors for the heavy lifting.

Something else to watch for if you DO get real power is other places may "need it."  I had the clout to keep them from putting a computer lab on our panel.  You may not be able to keep them from using your panel to also feed the concession stand with a pile of nesco rosters eating 100A.

[TJ (Tom) Cornish]

Agreed.... So while I'm teaching seminars in Texas this week (and not at my desk) I don't have a lot of time to thing about your questions this week. However, I would suggest that to future proof your system you add at least one "house power" connection. In the old days (before LED lights and Class-D power amps) I would have suggested camlocks and a 200-amp circuit breaker. However, I think it's time to revisit a trick I first used some 40 years ago in my misspent youth at the Old Mill Inn. A 50-amp/240-volt Range Outlet (NEMA 14-50) fed by a double-pole 50-amp circuit breaker in the service panel would allow most any medium size act to plug in their own power distro and run quite a large sound and lighting system. Unless you are doing major shows, then 100 or 200-amp camlocks seem like expensive overkill. But a 50-amp/240-volt range outlet located near the stage would give you a lot of future expansion options since that's 100 amperes of 120-volt power which is sufficient for a 10,000 watt PA system and a pretty large LED lighting system. I'll have to double check with my code monkeys, but this should be perfectly code compliant and WAY more legal than letting a visiting band hang some camlock pigtails out of your open circuit panel.

I would appreciate some input from the other sound pro's here. Does this seem like a reasonable distro power idea for a small/medium church or club, or is it too simple/crazy to work? Of course, really big productions need really big power from camlocks, but how much room do you have on stage for potential acts?

Mike, in my opinion the 14-50 is a very reasonable choice - still a good chunk of power, and inexpensive components.  Somewhere on one of the forums a few folks mentioned that there were potentially regional restrictions on using a 14-50 for general use and that a CS connector would be more appropriate, but in my region 14-50's are fine, and as you mentioned, infinitely better than panel spelunking.

The other way to go would be a "built-in" distro -  4-6 20A circuits on or near stage that would allow for extra tree-pack dimmers, or whatever.  I believe this is better for the other 51 weeks a year that production isn't brought in - the church wouldn't have to dig out the portable distro just to plug in a couple lights.

I suppose someone with a big amp rack that has a rack pack inside might be loathe to un-patch their amps from the rack pack, meaning a 14-50 would still be desirable, but then it gets to a cost/benefit question, and just how often that would be a problem.

[Jerome Malsack]

With some of the larger power amps for items like subs looking at 30 amp  should one consider having one or two 30 amp plugs installed in the amp and at the performance area??

[Mike Sokol]

With some of the larger power amps for items like subs looking at 30 amp  should one consider having one or two 30 amp plugs installed in the amp and at the performance area??

I do have a pair of MacroTech amps at the school with 30-amp connectors so that's a reasonable idea if you regularly roll out the BIG AMPS for certain gigs. However, I really don't like the TT-30 30-amp/12-volt outlet format since it's easily confused with a 30-amp/240-volt dryer outlet. See my NoShockZone article at http://www.noshockzone.org/accidentally-plugging-into-240-volt-outlet/ Now I'm not suggesting you can accidentally plug a TT-30 plug into a an old NEMA 10-30 outlet, but I have dozens of emails from RV owners who paid an electrician to wire up a TT-30 outlet for their 120-volt camper, but found it was miswired with 240-volts since it looks a LOT like a dryer outlet. Of course, plugging your 120-volt RV into an outlet miswired with 240-volts will destroy all the electrical gear in seconds. I still think that every good sound tech should meter all outlets before plugging in any sound gear. 

[Luke Richison]

Thanks for all the replies. I really appreciate the advice and knowledge shared. Even though a lot of it seems like overkill for my needs, I enjoy learning the ideal / theoretical applications. I'd really like to learn more about where to place certain elements in the supply chain (sorry if this is detailed in the resources listed in the first reply - I'm still working through them). For example: 200A service >> conditioner / limiter (at FOH?) >> PA mains, or service directly to PA?

Kevin, thanks for those resources. I had stumbled across the Mid-Atlantic paper (probably from the resources section of this forum) but found it a little daunting. I will give it and the others a read. I really appreciate it!

Mike, I really like the idea of pulling that 50A line to the stage. Thanks for the tip!

TJ, thanks for the quick reply. Sorry I couldn't respond sooner. Here's some more specifics about our space and current setup:

• Space (all measurements approximate)
  • 250 seats max
  • Wedge shaped, 115°
  • 2500 sqft
  • 12' drop ceiling
  • seating area (front of stage/PA to back wall)
    • 30 feet wide at stage, 85 feet wide at back wall
    • 40 feet deep
  • stage
    • 11 feet wide at back wall, 30 feet wide at front
    • 18.5 feet deep
    • We will use floor pockets to minimize cords and clutter
• A/V equipment (with specs found in owner's manual)
  • 2 Mackie HDA's - power requirements: 100-120 VAC, 50-60Hz, 200W; AC Connector PowerCon A 20A, 250 VAC, Max input 800W
  • 1 Mackie HD1501 subwoofer - power requirements: 100-120 VAC, 50-60Hz, 300W; AC connector: 3-pin IEC 250 VAC, 15A male
  • Presonus StudioLive 24.4.2 - input voltage range: 90 to 240 VAC, power requirements: 100W
  • iMac
  • on stage equiment / instruments: no floor monitors or amps
  • Video: 1 projector, 2 60-inch monitors
• lighting (not purchased yet)
  • Our church subscribes to "less is more" - we won't be doing anything too extravagant with lighting
  • House lighting (recessed can lighting) grouped in zones, dimmable
  • color wash on stage walls
  • front lights (white tungsten, as suggested by TJ)
  • This section of the budget would probably be the first to be postponed to a "phase 2"
  • We would rather spend the money to have the right power and audio setup, then buy proper lighting gear when more money is available, rather than scrimping on power & audio to make room in the budget for lighting

Thanks for all the advice.

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