Power distro questions and comments....

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K

knardini

DJ
Dec 3, 2006
1,618
6
51
Kansas City
I visited a venue in St. Louis today in preperation for an event I'm working there next month. When I walk in they are testing sound and lighting for a popular Pink Floyd cover group...and WOW the set up was awesome! 300 pars, about 30 large movers, lasers, a video projector the size of a small car!!!

Anyway.....the sound guy tells me that they don't have any individual circuits on stage, just 400 watt and 200 watt transformers dedicated for sound and lighting (3 phase). Even with my largest shows I've only needed 120 amps total, so I've never dealt with power distro boxes, I just hunt for circuits or bring a generator...so wondering if someone could

A) explain the difference between 1 and 3 phase...what exactly is a "tail" and how to go about getting a small distro box (4-6 20 amp circuits) without spending a fortune.

B) how does a school or reception venue not used to providing large amounts of power prepare for you to tie in your distro box? Do you do it or do they?

I'm totally new to this aspect of things so feel free to explain using 3rd grade words :sqwink:

btw...the whole place was heavily hazed in about 20 minutes with a single DF-50 - those things rock!

Thanks ya'll and Merry Christmas!!!!
 
Don't forget about asking around prosoundweb for some companies the St. Louis area if ya don't find what you need first.

I'm wondering if you can get one built Kris and maybe have an electrician show up to hook it up for you.....or just call an electrician directly, or check with the venue to see who they recommend.

good luck brother, jealous as always I am....

later,
 
Kris
The venues we work with either have the connects available (if they regularly have larger events, they will have 3 phase with special connectors so it's plug and play if you have a 3 phase or 220 distro). If the facility does not have disconnects, they will hire an electrician to install something (permanent or temporary). Most locations require by law an electrician to tie in pigtails directly to a panel. A 'band disconnect' may be provided; a place to tie in 220V pigtails...this is normally a lone box that must be switched off in order to open the box for tie-in. This is legal to tie into because there is no live power when the box is open.

3 phase is 3 legs of 220....220 is 2 legs of 110V.
 
As far as three-phase service goes, you may wish to read about it at the Wikipedia site. That's gonna be more to your benefit than my fumbling with this keyboard, trying to explain it. :D

As for your purposes with a distro you'll be using one or two legs of the incoming 240 volt service with the neutral. That will give you the 120 volts you need for equipment power. Some commercial 3 phase services utilize a 208 volt "high leg" for lighting.

You can have an electrician build a distro for you. That's the more cost effective method. And it will work just as well as the more expensive prefabbed rackmount models.

That said, I do not recommend going into a service panel and connecting up to the busbars unless you know exactly what you're doing. If there's any doubt, have a professional electrician do it for you. :)
 
When we talk 3 phase, are we talking standard 30A 3 phase 208? Why not just use a PDU like these http://www.apc.com/products/family/index.cfm?id=136?

In my day job when we built the datacenter whe decided to go all 30A 208 circuits and it's been a great thing. Everything does auto ranging power and there are transformers for everything if we need to step down. same for 3 phase...

and since there is prefab pdus - we are protected incase something goes wrong
 
3 phase power has 3 hot legs, a neutral, and a ground (5 wires total). They are usually 0000 cable. Most tails have bare copper at one end and a CAM-LOK connector on the other. The venue will provide a disconnect at 100, 200, or 400 Amps (large venues will have multiple disconnects). You (or the venue electrician) will connect the bare copper end of your tails into the lugs in the disconnect and then restore power. You plug the CAM-LOKs into your distro or dimmer rack in a certain order (green, white, black, red, blue). We often had a rider for 4 or more 400A disconnects.

As far as power itself, it depends on what type of 3 phase you are talking about. I would suggest a thorough reading about electricity from a variety of sources. There is just too much information for a post here.

Mike
 
If you're looking at distro for one event, hire an electrician or production company to provide it for you. I can't imagine you will find more than a select few events in your business that would require more than single phase distro. We do only a couple events a year at best that we use our three phase distro. You shouldn't be playing with three phase if you don't know electricity well. 220 is very forgiving as far as balanced loads...and provides a lot of juice.
 
Kris,
I built my own and had an electrical engineer check everything out before I plugged into my electrical panel. But, I'm in Mexico and just use it in my house or a friends house. Since you are up there have a licensed electrician build one for you that fits your needs with a little bit extra in case you add some more stuff in the near future. This will keep you on the safe side (Legal matters in case something goes wrong).
 
I cannot agree more that with the advise given already.

This is nothing to mess with unless you know EXACTLY what your doing.


That reminds me, I really need to take a picture of the buss bar @ the Rodeo that some sound god wanna be electrician damn near destroyed by not tying in power correctly!

It looks like someone threw a wrench in there and it welded itself to the bar..
Oh Yeah...Sounded like a Shotgun going off in your ear when it happened...
 
I had a roadie once tying into a 400A panel. He thought it was disconnected, and when he touched the allen wrench to the lug nut, BOOM! He was thrown 18 feet backwards, his hair was singed, and the allen was ruined, but other than that he was fine, thank God.

Mike
 
What happens if I purchase a 200 amp distro and the venue doesn't have that much to spare? Am I thinking about this wrong? I'm thinking about HS gyms and older spaces.
 
Even older commercial polyphase services are typically good for 200 amps or better. A larger venue like a gym would need it for the lighting load. If the gym doubles as an auditorium the service would have to be beefy enough to support stage lighting.

Issues may arise in older, converted houses that weren't equipped with a heavy service entrance. In cases like these you're limited to what's there.
 
knardini said:
What happens if I purchase a 200 amp distro and the venue doesn't have that much to spare? Am I thinking about this wrong? I'm thinking about HS gyms and older spaces.
Click to expand...

Most buildings will have service to the building, but not necessarily 200 amps not in use. Gyms typically are maxed at 50A 220 for access. Often times their lighting panels are not 110V and not useable, much less able to be disconnected with people in the building.
 
I'll stop @ The Rodeo and snap a pic of there panel for all to see...

People that need to do this, really should see what it can do to you...
 
jtnichol said:
Kris.....rent man....lol
Click to expand...

My problem with renting is that my "big rig" requires 140-160 amps to do it right. I would love to learn how to go about discussing tie-ins with places and instead of paying to rent, pay for an electrician to come and do it for me. Having access to all that power in one place would save so much time, cords and potential for blowing fuses, damaging gear...plus I would have one more cool piece of equipment :sqwink:

Don't know what it would cost to rent one of these ($100-$200??) I would be half way to one of these at least at that rate:

http://www.bhphotovideo.com/c/product/181336-REG/Furman_ASD_120_ASD_120_AC_Sequenced_Power.html
 
knardini said:
My problem with renting is that my "big rig" requires 140-160 amps to do it right. I would love to learn how to go about discussing tie-ins with places and instead of paying to rent, pay for an electrician to come and do it for me. Having access to all that power in one place would save so much time, cords and potential for blowing fuses, damaging gear...plus I would have one more cool piece of equipment :sqwink:

Don't know what it would cost to rent one of these ($100-$200??) I would be half way to one of these at least at that rate:

http://www.bhphotovideo.com/c/product/181336-REG/Furman_ASD_120_ASD_120_AC_Sequenced_Power.html
Click to expand...

If that model is what you need man, that's pretty cheap! I had and have no idea about this stuff...That's gonna be pretty handy for you as time goes on. I'm anxious to learn more young grasshoppa!
 
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