Sound & Stage Power

Re: Sound & Stage Power

In reading your replies, I wonder if you're confusing how current is spoken of (which would be understandable - it is confusing). A California 50A plug is potentially two legs of 50A at 120V so theoretically 100A possible current, but that doesn't make it a 100A circuit. It's still a 50A circuit. A better way to talk about this is a 50A two-pole circuit. An L14-30 feed is similar - two legs of 30A at 120V, but it's still a 30A two-pole circuit.
 
Re: Sound & Stage Power

As others have suggested L14-30 is way common in our field. The 50 amp connector, not so much
I would get L14-30 on your distro... Drop a stinger behind your pa in whatever configuration. Powercon, u ground whichever way you want to break it into your pa. Also if you ever forgot or broke your 30 amp cabling, you could purchase another at any home depot style store. A 50 cali connector, not so much...
 
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Re: Sound & Stage Power

Shane Presley said:
As others have suggested L14-30 is way common in our field. The 50 amp connector, not so much
I would get L14-30 on your distro... Drop a stinger behind your pa in whatever configuration. Powercon, u ground whichever way you want to break it into your pa. Also if you ever forgot or broke your 30 amp cabling, you could purchase another at any home depot style store. A 50 cali connector, not so much...
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I've not seen any distros built around L14-30 in my travels. Again, there is a fair amount of regional standardization in our industry, and every region tends to pick a connector and go with it.

Here's a list of the connectors that I'm aware of that are viable for temporary power distribution, along with some notes on use. Wire sizes noted assume that the neutral is counted as a current-carrying conductor, which is required if nonlinear loads (e.g. most switch-mode amplifiers) are on those circuits. In most cases, if your loads are all linear, you can drop down a size.

In order of available power:
Powercon (single 20A circuit) (12/3 wire)
NEMA 5-20 (standard Edison) (12/3 wire)
NEMA L5-20 (twistlock equivalent to Edison) (12/3 wire)
NEMA L5-30 (30A twistlock, occasionally used for larger power amplifiers) (10/3 wire)

NEMA L14-20 (20A split-phase twistlock, can be split into 2 20A 120V circuits with no additional OCPD. Occasionally found on larger gas generators) (12/4 wire)
NEMA L21-20 (20A 3-phase twistlock, can be split into 3 20A 120V circuits with no additional OCPD. Requires 3-phase feed) (10/5 wire) (12/5 with linear loads)
NEMA L14-30 (30A split-phase twistlock. Can be split into 4 15A 120V circuits with a sub distro. Occasionally found on larger gas generators) (8/4 wire) (10/4 with linear loads)
NEMA L21-30 (30A 3-phase twistlock. Can be split into 6 15A 120V circuits with a sub distro. Requires 3-phase feed ) (6/5 wire) (8/5 with linear loads)

California Standard 50A split phase (50A split-phase twistlock. Can be split into 2 20A and 4 15A circuits with a sub distro. Commonly found on small diesel generators and on construction sites) (4/4 wire) (6/4 with linear loads)

CEE-Form / Pin and Sleeve connectors (60A and 100A split-phase and 3-phase connectors. Generally used on the inputs of smaller distros.)
Cam-lock (individual feeder splice connectors, up 400A. Widely used on the inputs to distros)

Beyond this list, there are also the range plugs found in clubs (typically NEMA 14-50), the NEMA L15-20 plugs found on some motors and motor distros, and the NEMA L6-20 and L6-30 plugs found on larger moving lights and projectors.

For the OP's case, in the absence of any other factors (such as cross-rentability), I'd probably go with L21-20 if 3-phase was always available, or CS-50 if only split-phase were available. In the L21-20 case, a single run per line array hang is probably sufficient (but give yourself enough extra outputs on the distro to double up if needed), and you don't need breakers on your breakout. In the CS50 case, you'll need a sub-distro at each location.
 
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Re: Sound & Stage Power

Rob Timmerman said:
I've not seen any distros built around L14-30 in my travels. Again, there is a fair amount of regional standardization in our industry, and every region tends to pick a connector and go with it.

Here's a list of the connectors that I'm aware of that are viable for temporary power distribution, along with some notes on use. Wire sizes noted assume that the neutral is counted as a current-carrying conductor, which is required if nonlinear loads (e.g. most switch-mode amplifiers) are on those circuits. In most cases, if your loads are all linear, you can drop down a size.

In order of available power:
Powercon (single 20A circuit) (12/3 wire)
NEMA 5-20 (standard Edison) (12/3 wire)
NEMA L5-20 (twistlock equivalent to Edison) (12/3 wire)
NEMA L5-30 (30A twistlock, occasionally used for larger power amplifiers) (10/3 wire)

NEMA L14-20 (20A split-phase twistlock, can be split into 2 20A 120V circuits with no additional OCPD. Occasionally found on larger gas generators) (12/4 wire)
NEMA L21-20 (20A 3-phase twistlock, can be split into 3 20A 120V circuits with no additional OCPD. Requires 3-phase feed) (10/5 wire) (12/5 with linear loads)
NEMA L14-30 (30A split-phase twistlock. Can be split into 4 15A 120V circuits with a sub distro. Occasionally found on larger gas generators) (8/4 wire) (10/4 with linear loads)
NEMA L21-30 (30A 3-phase twistlock. Can be split into 6 15A 120V circuits with a sub distro. Requires 3-phase feed ) (6/5 wire) (8/5 with linear loads)

California Standard 50A split phase (50A split-phase twistlock. Can be split into 2 20A and 4 15A circuits with a sub distro. Commonly found on small diesel generators and on construction sites) (4/4 wire) (6/4 with linear loads)

CEE-Form / Pin and Sleeve connectors (60A and 100A split-phase and 3-phase connectors. Generally used on the inputs of smaller distros.)
Cam-lock (individual feeder splice connectors, up 400A. Widely used on the inputs to distros)

Beyond this list, there are also the range plugs found in clubs (typically NEMA 14-50), and the NEMA 15-20 plugs found on some motors and motor distros.

For the OP's case, in the absence of any other factors (such as cross-rentability), I'd probably go with L21-20 if 3-phase was always available, or CS-50 if only split-phase were available. In the L21-20 case, a single run per line array hang is probably sufficient (but give yourself enough extra outputs on the distro to double up if needed), and you don't need breakers on your breakout. In the CS50 case, you'll need a sub-distro at each location.
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Rob, your list is very helpful, and a great reference.

The reason I recommended L14-20 rather than L21-20 is that you can go directly to a Powercon connector at 208/240v (12/3 wire leaving the neutral in the L14-20 connector unconnected), and right into the speakers. This is potentially possible with L21-20 if you leave out one of the phases, but is more wasteful of breaker space, and a lot harder to follow when trying to figure out how things are powered.
 
Re: Sound & Stage Power

TJ Cornish said:
IMO, Soca is a poor choice for non-dimmed power distribution. The cable needs to be derated substantially due to a large number of bundled conductors, and there are traps depending on how they're wired - number of grounds, wire gauge, etc. It's also REALLY heavy.
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I don't mean any disrespect, but I don't think that multiconductor cable has to be derated as you say. I find folks reference that "bundling" code requirement, as taken out of context quite often. I understand that reference (if that is what you were speaking of), is meant to cover a group of conductors, tightly packed together through something like a wooden beam, that is 2' or greater - the key point here is that the heat on the conductors cannot be dissapated well. If the wires are in a rubber cable on the floor, or perhaps a metal or plastic conduit buried in cement, conduit hung on a wall, or suspended in free air - all those can dissapate the heat into the air, ground or cement. The wooden beam traps the heat, so that code reference is there to protect the conductors by derating/limiting them in that situation, that's the real intent of that code requirement.The standard 80% derating rule that applies to all conductors, is applied to multiconductor cables as well... at least that how I learned it in code classes (over and over...). If that was not your meaning or reference, then please forgive me.Socapex cable seems quite a handy method of handling the multiple branch circuits, and also by splitting those loads out as to reduce the total load on each circuit in that mannor, would also lower the voltage drop as stated by others on this thread. An additional advantage would be that the multiple circuits would provide additonal redundancy if something did cause a breaker were to trip out, the others would not.
 
Re: Sound & Stage Power

Declan Slater said:
I don't mean any disrespect, but I don't think that multiconductor cable has to be derated as you say. I find folks reference that "bundling" code requirement, as taken out of context quite often. I understand that reference (if that is what you were speaking of), is meant to cover a group of conductors, tightly packed together through something like a wooden beam, that is 2' or greater - the key point here is that the heat on the conductors cannot be dissapated well. If the wires are in a rubber cable on the floor, or perhaps a metal or plastic conduit buried in cement, conduit hung on a wall, or suspended in free air - all those can dissapate the heat into the air, ground or cement. The wooden beam traps the heat, so that code reference is there to protect the conductors by derating/limiting them in that situation, that's the real intent of that code requirement.The standard 80% derating rule that applies to all conductors, is applied to multiconductor cables as well... at least that how I learned it in code classes (over and over...). If that was not your meaning or reference, then please forgive me.Socapex cable seems quite a handy method of handling the multiple branch circuits, and also by splitting those loads out as to reduce the total load on each circuit in that mannor, would also lower the voltage drop as stated by others on this thread. An additional advantage would be that the multiple circuits would provide additonal redundancy if something did cause a breaker were to trip out, the others would not.
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I don't say, the NEC does. See section 400.5, which very explicitly spells out the rules for portable cords. A convenient free copy of the NEC can be accessed here: http://www.nfpa.org/assets/files/aboutthecodes/70/70-a2013-ropdraft.pdf You'll find this information on page 70-274.

Rubber - particularly thick rubber of SOOW cord is a fantastic insulator - both of electricity and heat. There are reasons for the rules.

Once again, trying to get away with sub-standard power cords is foolish. We spend tens or hundreds of thousands of dollars on our rigs, and it takes twice as many amps, boxes, truck space, capital investment, etc. to get a 6dB increase in output power. Excess voltage drop can easily rob several dB of output. Saving a few hundred dollars on copper is a poor investment.
 
Re: Sound & Stage Power

An update on my PD system.

First off, thanks for all the info. It kept me thinking for weeks. CS50, L14-30, or Soca were the final 3 options. All had plus/minus. In the end, the distro builder helped me to decide by telling me that almost all of his PD boxes
that they build for powered line array boxes were Socapex. So that is what i went with. It has (4) Soca outputs, (2 subs and 1 for each LA tower). It also has 6 20A edison's so that will certainly take care of me.

I got 60' and 80' 12/19 Soca cables with no shared grounds and I already had 4 Soca Edison breakouts so that is what I use up on the towers and behind the end fire sub array.

1 cable and no sub distro was the quickest/easiest setup I could come up with and that was very inportant.

Thanks again.
 
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