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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => AC Power and Grounding => Topic started by: Alex Donkle on May 28, 2017, 02:38:30 AM
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I was looking at plans for a big arena recently, and noticed they have dedicated "show power" rooms in each corner of the Arena floor. I'm familiar with show power in theatres and smaller arenas, but it's always just been wall mounted boxes (either simple disconnects or lockable company switches), does anyone know why large venues would dedicate rooms for this?
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Bigger arenas typically do bigger shows. So where a theatre or smaller arena may have 1 or 2 services available on each side of the stage, it wouldn't be uncommon for a large arena to have 5-6 services available on each side. Maybe (1) 800 amp, (2) 400 amp, (2) 200 amp, and a 100 amp service all contained inside a show power vault is easier to lock a door knob vs. individually locking out each disconnect.
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I was looking at plans for a big arena recently, and noticed they have dedicated "show power" rooms in each corner of the Arena floor. I'm familiar with show power in theatres and smaller arenas, but it's always just been wall mounted boxes (either simple disconnects or lockable company switches), does anyone know why large venues would dedicate rooms for this?
Arena's will also typically have dedicated power areas for busses to get shore power and, if they do sports, they will have at least one area that is a truck dock with power as well as connections for the camera system, headsets, audio so that all event coverage can be fed to the trucks.
Lee
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I've read that building codes are being updated for power rooms to require out swinging doors with crash bars in case of arc flash incidents.
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At our Little Arena on the Prairie (cap. ~15,000) we have 2 primary power vaults, upstage left & right. Each vault has a nice big hand-warmer (transformer) and 3 each 3ph 208/120v 400A services and 4 each 3ph 208/120V 200 A services. Each vault has 3ph 120/208V 200A services "satellite" disconnects that are in the far downstage L/R voms.
In addition there are a bunch of 100A 3ph 120/208V services on the catwalk, under the pull out grandstand seating, etc.
On the exterior of the building and south walls of the dock compound there are multiple 100A services, 2 each 400A and 200A services outside the guest catering room, and some smaller services for uses I've yet to determine (after 7 years there).
They also have 6 dedicated power pedestals for motor coach shore power, engine block heaters and misc exterior use.
There are probably services I've not used or haven't discovered.
As the architects and County were thinking "sports" and "TV" more that "concerts", there are a number of audio, video, comm & IT network boxes throughout the facility. The Coms, audio and video all end up at a media access room near the catering room for patching to broadcast trucks. Additional POTS lines, ISDN and temporary fibre hookups are in that room as well.
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Bigger arenas typically do bigger shows. So where a theatre or smaller arena may have 1 or 2 services available on each side of the stage, it wouldn't be uncommon for a large arena to have 5-6 services available on each side. Maybe (1) 800 amp, (2) 400 amp, (2) 200 amp, and a 100 amp service all contained inside a show power vault is easier to lock a door knob vs. individually locking out each disconnect.
So just how much power did they need for this show when the lights kick in on the big mirror ball around 6:46? This was in the 90's so that was traditional lighting instruments and a lotta Lasers. https://www.youtube.com/watch?v=vi7cuAjArRs&list=RDvi7cuAjArRs
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I've read that building codes are being updated for power rooms to require out swinging doors with crash bars in case of arc flash incidents.
The NEC requires that. Also, part of the NFPA 70E arc flash recomendations is that anyone that is not a "qualified" person be kept outside of a specified area. It's a lot easier to keep people out of room than out of an area, even if it is roped off. It would be a significant improvement for safety to all involved to have a power room.
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Thanks for all the helpful responses.
Assuming most of these rooms just have large access panels in the wall to pull cables out toward the main Floor?
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So just how much power did they need for this show when the lights kick in on the big mirror ball around 6:46?
Let the Waaaayback machine help, since the original appears to be broken: All the gory details (https://web.archive.org/web/20110609164735/http://www.pinkfloyd-co.com/band/interviews/art-rev/art-ld.html).
The mirror ball was rotting in a container in the UK a dozen years ago, and may still be there...
Update: Looks like it may have been rescued from the container and moved to the V&A: Stuffish and the Pink Floyd Mortal Remains exhibition (http://www.stufish.com/project/the-pink-floyd-exhibition-their-mortal-remains-presented-by-london-s-v-a)
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Not typically "large" holes. Large enough to pass several sets of 4/0 feeder through. I'd say typically an opening the size of a standard cinder block or two. Certainly not large enough for a person to crawl through. That would defeat the purpose of having a lockable vault.
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Thanks for all the helpful responses.
Assuming most of these rooms just have large access panels in the wall to pull cables out toward the main Floor?
In the 2 power rooms I mentioned above the walls are concrete block and there is one block missing from the bottom row to pass cables through. I've posted pics from one of the rooms before but I can't find the posts here so I may repost them if they're still on my phone...
2 of the 200A services and 1 of the 400A services are on Union Connector company switches (link below), the others terminate to plain gray steel boxes with Crouse-Hinds E0200 and E0400 panels like the ones linked below, but with double neutrals.
https://www.unionconnector.com/product/company-switch-with-series-16-safecam-receptacles-and-connection-chamber-400-amp
http://www.cooperindustries.com/content/public/en/crouse-hinds/brands/posilok.html
PosiLok panels have mechanically interlocked connector covers to force proper connection/disconnection order and the connector back shells are keyed in a way that prevents mating with the wrong conductors.
The Union Connector switches have plunger-type Microswitches in the CamLok female connectors. Failure to completely connect all CamLoks will not allow the shunt trip to close and the main breaker cannot be engaged. Because the architects specified double neutrals there is a dummy CamLok for the 2nd neutral. Also these switches have a connection chamber to directly tie in tails or feeder without CamLoks. If the chamber door is opened the shunt trip opens too, de-energizing the switch.
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So just how much power did they need for this show when the lights kick in on the big mirror ball around 6:46? This was in the 90's so that was traditional lighting instruments and a lotta Lasers. https://www.youtube.com/watch?v=vi7cuAjArRs&list=RDvi7cuAjArRs
Ummm. All of it ? ::)
I seem to recall when they were here (Big OWE, Montreal) that they had a couple of Tractor-Trailer mounted Gensets to "help" the local Hydro.
Chris.