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Author Topic: Distro Questions, amp rack tie in  (Read 2561 times)

Tim McCulloch

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Re: Distro Questions, amp rack tie in
« Reply #20 on: March 09, 2017, 09:33:01 pm »

Thanks Tim.  That was along the lines of what I was thinking, but the "NEMA 3R Weather Resistant" versus "NEMA TYPE 3R Rainproof" was confusing me.  The Pagoda Jr. still advertises "elevated base keeps receptacles above ground level", so I wasn't sure if there's a specific difference in needs to meet UL/NEC/OSHA requirements for outdoor use in general, or if there are additional requirements for use outdoors in the portable entertainment industry.

I believe the requirement is 6 inches off the ground and I think that's an OSHA regulation.

I don't have access to my copy of the NEC on this tablet, but outdoors our work falls under 525, inside it's 520.  There are exceptions to parts of Chapters 3 & 4 in 640.  The general principles in Chapter 2 and especially 250, along with Chapter 3 and 4 (as pertaining to flexible cables particularly) are must-reads.
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Stephen Swaffer

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Re: Distro Questions, amp rack tie in
« Reply #21 on: March 09, 2017, 09:58:41 pm »


It's OK to have a your 20A receptacle on a 15A breaker, but you can't go the other way. For example, you couldn't put a 20A receptacle on a 30A breaker. You could put a 400A camlock on a 15A breaker if you wanted to though...........

Having a two pole breaker on 2 separate circuits is technically OK, but not ideal. If one circuit trips for some reason, it will take down the other circuit as well.

Actually, it is not acceptable to use a 20 A receptacle on a 15 A circuit.  NEC 2014 table 210.21(B)(3).  20 amp plugs are installed on loads that could potentially overload a 15 amp circuit before the breaker trips.

Typically, common trip breakers are used with a shared neutral.
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Jeremy Young

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Re: Distro Questions, amp rack tie in
« Reply #22 on: March 09, 2017, 10:30:40 pm »


Just wanted to give a huge THANK YOU to everyone's advice/experiences.  This forum is incredible.  I'm in the process of "legitimizing" my weekend warrior/lounge level company, spending on cases and and stands and other less-exciting but extremely important gear.


it didn't take much to push me into retiring this beast, so I'm happy to say that this distro (no autocorrect I don't want to type bistro thank you) will be officially decommissioned and ritualistically burned for the sake of safety.  Or fun, mostly fun.


First thing, no, you can't take 2 15A circuits and combine them into one 30A circuit. Well, you "could" if they were on the same phase, but it wouldn't be legal or safe. It's not possible at all if they're on separate phases, unless your goal is to have your distro weld itself together. The only safe solution to power your 30A receptacle is to install a single pole 30A breaker and replace the wiring on that circuit with a heavier gauge.
 


I knew there was something about my plan that wasn't sitting right.  Thanks for the clarification.  Definitely not going down that path.


It's OK to have a your 20A receptacle on a 15A breaker, but you can't go the other way. For example, you couldn't put a 20A receptacle on a 30A breaker. You could put a 400A camlock on a 15A breaker if you wanted to though.


interesting, makes sense now that I think about it, and Tim's other comment helps me clarify a few things in my head: 

[/size]

To the OP - your distro is unsafe using #10 wire with a 50A plug, even if downstream breakers theoretically limit the current draw to 30A.  It's low-enough quality that I would abandon it and do as Ray said and get a construction-style listed spider box with an appropriate #4 feeder cord for the 50A load.


so, upstream of breakers, the wire needs to be sized for the breaker protecting it or larger; but downstream of breakers, one could fit a larger wire/receptacle than the current carrying capabilities of the breaker safely, since the breakers would trip long before the high-current load got to dangerous levels.  Got it, although my recap sucks.




I think you'd be better off with a 50A distro, which could have the 30A and a 20A circuit on the same leg. Honestly you'd probably be better off with a different panel in your amp rack too, maybe with a L14-20 or 14-30 rather than a L5-30, which could split your amp load between the 2 legs rather than having them all on a single leg. It would be more balanced, and the draw wouldn't be so heavy on just one leg. Would it be possible for you to rewire the amp rack panel to make it 2 circuits instead of 1?




I can definitely (rather, someone I would hire can definitely) rewire the panel, but as I mentioned I just sort of came into it, and it was only really attractive to me because it was 115v, and I thought the dual cable thing might make sense for times when I'm not using a distro.  would the other connection types you've cited be 230v or 115v?  or a bit of both that's over my head?  I work in mechanical construction trades, but anything bigger than low-voltage control wiring makes my head spin for some reason.


No need to use 8ga cable for your amp rack when the cable that feeds the distro is only 10ga. 10ga is probably fine for your amp rack in any case. That's basically all I ever see on 30A circuits around here.

You're right, ground and neutral should not be bonded in a distro like this, they should be passed through individually. The bonding should only be done at the service entrance.

Your distro is small, and the mini breakers aren't as robust as full size breakers. There's also nowhere to add a 30A breaker without removing another circuit. If you're already planning on spending a few hundred bucks, you could probably rebuild (or replace) the whole thing for that amount.

Also, don't build a whole separate cable for your Edison to 30A cable, just build a short 12ga adapter from Edison to twist. And I'd rather see a panel mount receptacle in a box rather than a cable mounted connector, but that's up to you to decide.




all good advice, thank you. 


My plan going forward is to go the 50A route and buy something listed for the application.  As I mentioned in my original post, nema14-50R's can be found easily for me, and it only makes sense that I utilize all of that available capacity since I'll definitely be growing into this. 


There is some attraction to the racpacs and the like, since I could install them in my amp rack now (where I need the power, and where that patch panel currently resides).  But those outdoor rated LEX products seem quite helpful for the occasional (for now, likely more soon) outdoor events I do where GFCI's would be appreciated.  If I went with a non-rack mounted distro, I think I'd still want to find a way to patch a single cable to my amp rack for power.  I don't like the idea of a spider box sitting next to my amp rack, or of a half-dozen extension cords between the amp rack and the spider box.  Question: does a rack-mounted distro (mounted higher than 6" off the ground) typically satisfy the 6" ground clearance outdoors?  Or does the metal rack ears/shell make it somehow less safe?  I guess those feet are metal on the LEX product...


What's the industry standard approach to this?  Are people running 30A 230v to their amp racks from their distro to a sub-distro of some kind in the amp rack, or is it just a 115v line with 20-30A capacity? 


The Furman ASD120 looks interesting too, as far as listed/rack mounted distro's go.  the sequencing feature might even help to let my mixer boot up before the amps turn on, or my router boot up before I fire up the mixer, so I don't have to babysit that stage of the setup and can spend that time taping cables or storing cases.  Anyone have anything bad to say about that product?  I can't seem to download the data sheet on their website; anyone know if this is a listed device?


I will not be doing any "tying in", using camloks, or anything like that.  I'm just trying to streamline my a/c distribution plan for minimal cable connections on site and maximum headroom without violating any codes/putting anyone at risk.  I'd rather buy something listed and rated for 50A now, than spend money on something that already has the writing on the wall, even if it's not YET being locally enforced.


Does anyone know of a "listed" version of a poor man's distro?  Or is that concept too far beyond getting any sort of listing?  I mean, for the gigs where I can't tie in a distro, I'm not usually bringing the amp rack either (just some powered SOS) so maybe something like that would be better, coupled with a rack mounted distro with detachable locking feeder cable for the bigger gigs.  if there isn't a detachable cable I could just get a nema14-50 extension cable.  then maybe a couple short adapters if I ever find myself in front of a "cali" plug like Ray suggested....short adapters make more sense to me than more single-purpose cables.


again, really appreciate everyone's guidance and time on these forums and in this thread. 
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Rob Spence

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Re: Distro Questions, amp rack tie in
« Reply #23 on: March 09, 2017, 11:40:11 pm »

Just wanted to give a huge THANK YOU to everyone's advice/experiences.  This forum is incredible.  I'm in the process of "legitimizing" my weekend warrior/lounge level company, spending on cases and and stands and other less-exciting but extremely important gear.


it didn't take much to push me into retiring this beast, so I'm happy to say that this distro (no autocorrect I don't want to type bistro thank you) will be officially decommissioned and ritualistically burned for the sake of safety.  Or fun, mostly fun.


I knew there was something about my plan that wasn't sitting right.  Thanks for the clarification.  Definitely not going down that path.



interesting, makes sense now that I think about it, and Tim's other comment helps me clarify a few things in my head: 

[/size]

so, upstream of breakers, the wire needs to be sized for the breaker protecting it or larger; but downstream of breakers, one could fit a larger wire/receptacle than the current carrying capabilities of the breaker safely, since the breakers would trip long before the high-current load got to dangerous levels.  Got it, although my recap sucks.




I can definitely (rather, someone I would hire can definitely) rewire the panel, but as I mentioned I just sort of came into it, and it was only really attractive to me because it was 115v, and I thought the dual cable thing might make sense for times when I'm not using a distro.  would the other connection types you've cited be 230v or 115v?  or a bit of both that's over my head?  I work in mechanical construction trades, but anything bigger than low-voltage control wiring makes my head spin for some reason.



all good advice, thank you. 


My plan going forward is to go the 50A route and buy something listed for the application.  As I mentioned in my original post, nema14-50R's can be found easily for me, and it only makes sense that I utilize all of that available capacity since I'll definitely be growing into this. 


There is some attraction to the racpacs and the like, since I could install them in my amp rack now (where I need the power, and where that patch panel currently resides).  But those outdoor rated LEX products seem quite helpful for the occasional (for now, likely more soon) outdoor events I do where GFCI's would be appreciated.  If I went with a non-rack mounted distro, I think I'd still want to find a way to patch a single cable to my amp rack for power.  I don't like the idea of a spider box sitting next to my amp rack, or of a half-dozen extension cords between the amp rack and the spider box.  Question: does a rack-mounted distro (mounted higher than 6" off the ground) typically satisfy the 6" ground clearance outdoors?  Or does the metal rack ears/shell make it somehow less safe?  I guess those feet are metal on the LEX product...


What's the industry standard approach to this?  Are people running 30A 230v to their amp racks from their distro to a sub-distro of some kind in the amp rack, or is it just a 115v line with 20-30A capacity? 


The Furman ASD120 looks interesting too, as far as listed/rack mounted distro's go.  the sequencing feature might even help to let my mixer boot up before the amps turn on, or my router boot up before I fire up the mixer, so I don't have to babysit that stage of the setup and can spend that time taping cables or storing cases.  Anyone have anything bad to say about that product?  I can't seem to download the data sheet on their website; anyone know if this is a listed device?


I will not be doing any "tying in", using camloks, or anything like that.  I'm just trying to streamline my a/c distribution plan for minimal cable connections on site and maximum headroom without violating any codes/putting anyone at risk.  I'd rather buy something listed and rated for 50A now, than spend money on something that already has the writing on the wall, even if it's not YET being locally enforced.


Does anyone know of a "listed" version of a poor man's distro?  Or is that concept too far beyond getting any sort of listing?  I mean, for the gigs where I can't tie in a distro, I'm not usually bringing the amp rack either (just some powered SOS) so maybe something like that would be better, coupled with a rack mounted distro with detachable locking feeder cable for the bigger gigs.  if there isn't a detachable cable I could just get a nema14-50 extension cable.  then maybe a couple short adapters if I ever find myself in front of a "cali" plug like Ray suggested....short adapters make more sense to me than more single-purpose cables.


again, really appreciate everyone's guidance and time on these forums and in this thread. 


I have an Amp Shop 30a 240v unit in my amp rack.  My main distro is 50a with an L14-30 on it to feed the amp rack. I use CS 50a connectors with a short CS to 14-50 when one of those connectors is available to use. Having all the feeder be CS makes it easy to connect to generators since all the diesel units have CS connectors.
While not strictly code compliant, I have a 50' and a 100' feeder and in a pinch can make up a 150' by plugging them together.



Sent from my iPad using Tapatalk HD
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Ray Aberle

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Re: Distro Questions, amp rack tie in
« Reply #24 on: March 10, 2017, 02:30:27 pm »

Jeremy,

To answer your question about power to amp racks-- yes. Typically there's a main distro that will then feed smaller units (commonly known as RackPacks) in the amp racks. I just posted this in the Classic LAB regarding amp rack setups. That's one of our main VerTec amp racks. Main distro gives me 12ch of L21-30; I then feed our racks from there.

So, you could get the spider box, and also one of these RackPacks with a CS6364/CS6365 I/O. You probably won't draw more than 50A/leg ever, so having everything on one feed will be OK. Then there is the flexibility- you can use the spider box, or the racked distro, or both-- always depending on the needs of your show!

-Ray
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Stephen Kirby

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Re: Distro Questions, amp rack tie in
« Reply #25 on: March 10, 2017, 04:21:13 pm »

Every spider box I've seen has a CS through on it.  Many will also have 30A circuits on them.  Which should handle an amp rack easily with a small rack distro.

The OP may be over thinking how much goes into the amp rack.  Outside of some varsity rigs, most amp racks don't draw that much.  At max rated output the Crest Pro 9200 I use for my subs can pull 30A.  But with music, it's a fraction of that.  Most amp racks at the lounge level that one or two people can move can exist on a 20 or 30A service.  Before going to so many powered speakers when I had a tri-amp rig, I ran two circuits of 20A on PowerCons from the distro to my amp rack.  With one on the subs and the other going to the mid and HF amps.  Probably overkill for that as well.  Many times I had to run that rig off wall outlets and got by fine with one 20A.  There are lots of threads talking about realistic power draws.  I do one city park series off two 20A wall outlets.

IMHO the safest bet without spending a fortune is a construction spider box.  Initially if there are a lot of amps in one rack, one can run a couple of 20A lines to the box from a couple strips in the rack if doing a maxed out outdoor gig.  Later on buying a 30A rack pack.
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Mark Cadwallader

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Re: Distro Questions, amp rack tie in
« Reply #26 on: March 10, 2017, 05:13:27 pm »

Re:  spider box. Getting one with L5-20 recepticles means that nobody is likely to "borrow" some power, and folks are less likely to disconnect one of your cables so they can plug in their phone charger.
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Ray Aberle

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Re: Distro Questions, amp rack tie in
« Reply #27 on: March 10, 2017, 05:28:46 pm »

Every spider box I've seen has a CS through on it.  Many will also have 30A circuits on them.  Which should handle an amp rack easily with a small rack distro.
Typically the 30A outlet on a spider box is an L6-30, which isn't easily suitable for us. I know some local providers who retrofitted their spider boxes with an L14-30 instead. MAKE SURE YOU ARE QUALIFIED TO MODIFY A SPIDER BOX IF YOU CHOOSE TO DO SO.

-Ray
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Jonathan Johnson

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Re: Distro Questions, amp rack tie in
« Reply #28 on: March 10, 2017, 11:19:18 pm »

Re:  spider box. Getting one with L5-20 recepticles means that nobody is likely to "borrow" some power, and folks are less likely to disconnect one of your cables so they can plug in their phone charger.

You could post a sign, "This is a 20 AMP outlet. It will BLOW UP your 2 AMP phone charger."
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Mark Cadwallader

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Re: Distro Questions, amp rack tie in
« Reply #29 on: March 11, 2017, 01:08:47 pm »

You could post a sign, "This is a 20 AMP outlet. It will BLOW UP your 2 AMP phone charger."

If those folks bothered to read the sign, they would probably figure "I'm OK, it's 'just for a minute or two.'  Anyway, my phone charger doesn't have any amps anyway because it just charges my phone, it doesn't make it louder."
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