Researching Power Distro Purchase

Josh Rawls

Member
I am reserching to buy a power distro, used or new. Here are my needs:

  • 50-100 amp single phase 208-240v
  • 25-50ft feeder cable
  • Adapters to connect to feeds with camlock, L14-50, or California twist-lock (any other type of twist-lock I might run into?)
  • All 20a 120v Edisons outputs
  • Rack mount or spider box

This will be used at campsites to plug into 50amp RV outlets (after proper testing!), hotel ballrooms, school gymnasiums, and the occasional generator.

This is my first distro purchase so I'm looking for advice on anything I missed.
 
In the U.S. it's not going to be single phase with either 208v or 240v.

208 is commercial supply and might be 2 or 3 legs off a 3 phase feed or 240v 2 legs off a non commercial supply, but nitpicking as the end result is you will be tapping 2 or 3 legs at 60 amps or so of 120v each for however many 120 volt outputs.

Lots of companies make these units - Lex comes to mind. Motion Labs is another.

Lex will custom to what you want, if of you want a unit with a short Bento box style feed pigtail that supplies 6x20 amp breakers Edison outlets , they can make it. Then get whatever 25 ft extension for the pigtail and whatever adapters you need. If using outdoors you might want to consider a GFCI protected box, in the event that the RV supply isn't.

We use an off the shelf Lex Bento for sound distro. It has a 30 amp, 120v, 3 pole twist male plug on a pigtail, plus we have 2x 25 and a 50 ft. ext. cables, with 2 receptacles, one ea. SL and SR. The box gives us 6x15 amp single edison receptacles , all breakered.

I think we paid about $600 for the whole package and use it with our audio monitor setup. Very cost effective and well made.
 
In the U.S. it's not going to be single phase with either 208v or 240v.

208 is commercial supply and might be 2 or 3 legs off a 3 phase feed or 240v 2 legs off a non commercial supply, but nitpicking as the end result is you will be tapping 2 or 3 legs at 60 amps or so of 120v each for however many 120 volt outputs.

Thank you for correcting me on my input voltages.

I am looking for GFCI units but most that have them seem to be for construction sites or carnivals. I'm not certain that makes a difference. (edit: I just saw the Lex Pagoda. It could be just what I'm looking for.)

I'll take a look at the Lex products.
 
GFCI and dimmers do not get along well.
That's an understatement and I thank Rick for it. In '95 I was involved with the first professional production of the Who's Tommy in Offenbach (Frankfurt am Main) Germany. The production required well over 400 dimmers. The local producer dealt with his favorite rock 'n roll lighting supplier who provided a small mountain of 6 and 12 dimmer packs. Not quite what the U.S. based LX designer and LX design associate were anticipating. Every "pack" had it's own GFCI main breaker. Initially "Tommy" began life in San Jose California before touring the U.S. and settling into Broadway's St. James for a lengthy run. On Broadway the show ran on an Obsession and this is what was spec'd for Germany as well. When the LX design associate arrived, he loaded his discs in, did his patch and basically retched when he watched his chases trying to run with various circuits of chases spread across multiple packs, thus multiple GFCI's. Dimmers, chases, multiple GFCI's: A bad combination all around.
Trust RickR, he knows whereof he speaks.
Toodleoo!
Ron Hebbard.
 
For what you're looking for, Lex....overpriced rubber covered BS. Get your self a Leviton or CEP construction spider box and feed it with 6/3 SEOW.

I've used a CEP box (60A@240 x 6 circuits) to utilize the full output of small generators, sometimes connecting through a CS connector, other times tied it in to panels through a 60A 2 pole breaker. Very handy.
 
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Did you not read the original post ?

The OP wanted an option for 208v which somewhat implies he might want a 3 phase connection OR a 240v single phase with 2 hots. 6/3 doesn't give him that.

Yes he stated single phase at 208, but that's not what he gets.
 
I read that his posting of 208VAC was a misunderstanding, nor do I read anything in post 1 or 3 which states 3 phase power. I posted a workable solution and you want to nitpick. I'm done.
 
Thanks for all the replies. I'll try to clarify a few things.

  • I should have just said 220v input, that was my error.
  • If I am supplying off of camlock I understand that I can just use two of the phases and not hook up the "wild" leg. Let me know if I am wrong about that.
  • I am open on rack mount or spider box depending on price. If the spider box is less expensive than a rack mount and a rack then I will go that way. Is there something I am missing feature wise between the two? It seems to me like it is just a difference in form-factor.
  • The CEP 7706GU has caught my eye, seems to be a good solution at a good price. Any reason at all not to use it, besides GFCI (since I'm not using dimmers I don't think GFCI will be an issue)
 
Did I state this in a manner that not understandable? Three conductors plus ground, that's black, red, white and green, so it's actually 6/4 cable. You can even buy them pre-connectorized. http://inverterservicecenter.com/Shop-By-Catagory/Shore-Power/Shore-Cords/50-Amp-Shore-Cords
Your post is understandable, but it's incorrect. NM cable does not count the ground wire in the naming convention - i.e. 12/2 NM has black, white, and bare conductors - 3 wires. SO cord uses a different naming convention - 6/3 cord only has a black, white, and ground. You need 6/4 cord to get the red conductor.

You might think it's nitpicking, but being precise is critical in power distribution.

And by the way, code requires #4 wire for 50 amps with 3 current carrying conductors, so neither 6/3 or 6/4 is acceptable (thought 6/4 is commonly used).
 
Thanks for all the replies. I'll try to clarify a few things.

  • I should have just said 220v input, that was my error.
  • If I am supplying off of camlock I understand that I can just use two of the phases and not hook up the "wild" leg. Let me know if I am wrong about that.
  • I am open on rack mount or spider box depending on price. If the spider box is less expensive than a rack mount and a rack then I will go that way. Is there something I am missing feature wise between the two? It seems to me like it is just a difference in form-factor.
  • The CEP 7706GU has caught my eye, seems to be a good solution at a good price. Any reason at all not to use it, besides GFCI (since I'm not using dimmers I don't think GFCI will be an issue)
In the U.S. it's not going to be single phase with either 208v or 240v.
240v is generally considered single-phase, as it's derived via a center-tapped transformer from a single distribution phase. Saying 220v is not really more correct than saying 208/240, and in fact is a pretty outdated number.

For the purposes of entertainment power, we can pretty much disregard whether we get 208v or 240v across two legs of our distro. Other than a few old moving lights, nearly all equipment that will accept 240v will also accept 208v, and vice versa, usually without adjustment. Practically speaking in the context you are referring to, 3-phase means we have three hot legs, single-phase means we have two hot legs.

You mention "wild-leg". This is something to be aware of, though thankfully it's getting less common. Testing your supply will tell you what kind of power you have. If you're using a 14-50 receptacle and you meter 120v between each hot leg and neutral, you should be fine if you read either 240v or 208v between the legs. If you read 208v from one hot leg to neutral, the receptacle is dangerously miswired to a wild-leg service.

If you are using cams to a three-phase service and all three legs read 120v leg to neutral, you don't have a wild-leg supply, and you should be OK.
 
We use an off the shelf Lex Bento for sound distro. It has a 30 amp, 120v, 3 pole twist male plug on a pigtail, plus we have 2x 25 and a 50 ft. ext. cables, with 2 receptacles, one ea. SL and SR. The box gives us 6x15 amp single edison receptacles , all breakered.

I think we paid about $600 for the whole package and use it with our audio monitor setup. Very cost effective and well made.


So, forgive me if this makes me a total idiot for asking.

I have been doing some research on Distro boxes and i am having such a hard time figuring out the numbers.

Heres the question.

from the comment above, how do you get 6x15 amp Edison receptacles form 30amp 120v twist lock plug?

Another case, i saw this one video, in which, ( training video from a distro box manufacturing company CEP)

he's plugging a distro box, which has 4 x 20amp outlets, in a 30amp 120/250v (7500w gen)

i am trying to understand how that worked out?

hears how i try to understand it, and got totally confused.

30amp X 250v will give you 7500W.

7500W/120v= 62.5Amps

62.5amp / 20amp = 3.124

meaning you should only be able to get 3 20Amp outlets.. how in the world are they providing 4 outlets. ( EDIT: i think i figured this out? they have 4 20 amp out lets but that doesnt mean there is 4 20 amp outlet worth of power available. the generator which was rated for 7500 would trip its breaker if all 4 outlets were pulling 20 amps. at-least that's what i am thinking.)
I Still want to know what SteveB meant.

If someone can please explain that would be greatly appreciated.
 
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This is shore power, not a generator. The breaker is a 30 amp 3 pole (120/208v)

The feed connectors are 3 pole, 5 wire, so 3 hots, neutral and grounding. 3x30 = 90 amps available, divided by 6 - 5-15 Edison receptacles = 15 amps per receptacle.

http://www.lexproducts.com/products...0-amp-bento-box-to-nema-receptacles-feed-thru

EDIT: Here's a picture. Our version doesn't have feed-thru

Oh wow that makes lot of sense now. thank you so much for that information.

So, correct me if i am not understanding this correctly but, you would use twist lock connections when power is being pulled over 2 or more phase lines?
 

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