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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: Sam Saponaro Jr on October 02, 2019, 12:12:26 am

Title: Electrical codes in building DIY distro?
Post by: Sam Saponaro Jr on October 02, 2019, 12:12:26 am
Are there any electrical codes that need be followed when building a 220V distro?? I did go through residential/commercial electrical back in high school so I'm familiar with hooking sub panels,proper grounding etc....But anything I should know as far as the tie in end??
 My simple little plan is for a small 4 circuit distro. Plan to Mount a small subpanel (the type that has no main just space for 4 single or 2 double poles)to ply wood. 4x 20amp single pole breakers each breaker feeding a 4x4 "quad box" mounted to the plywood. Use 12ga. MC cable to feed the quads. Now my plan is to use a 6' 50 amp electric range pigtail to feed the panel(the kind with a 50 amp 4 conductor plug on it). Allot of places I've worked have a 50 amp outlet at the stage.
Next plan was to make and extender cable,useing range cable with a 4 conductor 50amp outlet on one end and stripped end on other for locking into a panel if no 50amp plug is available. Plan to carry a couple differant 50 amp double pole breakers(Square D type Westinghouse type)
 Mainly I need a circuit for Main PA(main amps,processing mixer),one for Sub amps and two for lighting(still hauling par 56s ugh!!). So a simnple 4x 20 amp should do. Figure two 20 amp breakers per leg is 80% load on a 50 amp main(on building panel).
Sound Good?
Title: Re: Electrical codes in building DIY distro?
Post by: Scott Holtzman on October 02, 2019, 12:48:57 am
Are there any electrical codes that need be followed when building a 220V distro?? I did go through residential/commercial electrical back in high school so I'm familiar with hooking sub panels,proper grounding etc....But anything I should know as far as the tie in end??
 My simple little plan is for a small 4 circuit distro. Plan to Mount a small subpanel (the type that has no main just space for 4 single or 2 double poles)to ply wood. 4x 20amp single pole breakers each breaker feeding a 4x4 "quad box" mounted to the plywood. Use 12ga. MC cable to feed the quads. Now my plan is to use a 6' 50 amp electric range pigtail to feed the panel(the kind with a 50 amp 4 conductor plug on it). Allot of places I've worked have a 50 amp outlet at the stage.
Next plan was to make and extender cable,useing range cable with a 4 conductor 50amp outlet on one end and stripped end on other for locking into a panel if no 50amp plug is available. Plan to carry a couple differant 50 amp double pole breakers(Square D type Westinghouse type)
 Mainly I need a circuit for Main PA(main amps,processing mixer),one for Sub amps and two for lighting(still hauling par 56s ugh!!). So a simnple 4x 20 amp should do. Figure two 20 amp breakers per leg is 80% load on a 50 amp main(on building panel).
Sound Good?

Nope, those panels are UL listed for installation not portable use. 

My advice is just pick up a lunchbox distro from Lex and be done with it.

Title: Re: Electrical codes in building DIY distro?
Post by: Erik Jerde on October 02, 2019, 12:51:15 am
Yes, lots of codes to follow.  Perhaps the most pertinent is that distorts now have to be listed.  This effectively ends your plans if you donít want to risk getting shut down by the local AHJ.
Title: Re: Electrical codes in building DIY distro?
Post by: Sam Saponaro Jr on October 02, 2019, 01:10:50 am
Ooohh.........and there you have it.
Wow I remember allot of bands with homemade distros not terribly long ago made from service entrance panels and long cables with both breakers and (Eeekk) clamps.Hell we had a panel mounted in a rack with a gazzilion foot feeder cable and breakers to terminate at the panel with one group I was with. Either they were illegal then or codes have changed....either way there goes that idea. :( :(
Title: Re: Electrical codes in building DIY distro?
Post by: Jeff Bankston on October 02, 2019, 01:59:02 am
Here in los angeles it would need to be safety approved and that cost lots of money. Get a Lex.
Title: Re: Electrical codes in building DIY distro?
Post by: Tim McCulloch on October 02, 2019, 10:00:16 am
Ooohh.........and there you have it.
Wow I remember allot of bands with homemade distros not terribly long ago made from service entrance panels and long cables with both breakers and (Eeekk) clamps.Hell we had a panel mounted in a rack with a gazzilion foot feeder cable and breakers to terminate at the panel with one group I was with. Either they were illegal then or codes have changed....either way there goes that idea. :( :(

I remember Tweco clamps, undersized feeders and open knock outs in breaker panels screwed to plywood.  Those won't pass muster these days.

Recently changed Code now requires "Listed" (as in by UL or other appropriate authority) *assemblies*, not just Listed components.  Getting a distro Listed is expensive - because it's about more than just 1 unit, it's about the shop, materials, methods and procedures.  For example, LEX, TMB ProPower, Indu, Whirlwind, Motion Labs... all have UL-Listed shops and they spend a whole bunch of $$ getting those Listings (far more than for just 1 product) so they can build a variety of designs, not just 1 or 2 products.

JR designed a nifty little outlet tester that could detect RPBG (reversed polarity, bootleg ground) Edison outlet wiring.  It was a simple device with about 6 components.  It was going to cost over $10k to get it UL Listed.

While I don't recall hearing about any recent electrical fires or personal injuries from "lesser" distros, the NFPA 70 committee has been tightening the standards for portable switchboards over the last couple of Code cycles.  They seem to think there are still some shady and potentially dangerous portable AC systems out there.

If your locale has not adopted the most recent Codes you *might* get away with a home-brew distro for awhile.  Your chances of being inspected are proportional to the level of events you do:  working bars and clubs means you'll probably never see an inspector but doing county fairs, municipal events, anything with temporary demountable entertainment structures (stages and roofs) significantly increase the likelihood of inspector visits.
Title: Re: Electrical codes in building DIY distro?
Post by: John Roberts {JR} on October 02, 2019, 10:53:02 am
I remember Tweco clamps, undersized feeders and open knock outs in breaker panels screwed to plywood.  Those won't pass muster these days.

Recently changed Code now requires "Listed" (as in by UL or other appropriate authority) *assemblies*, not just Listed components.  Getting a distro Listed is expensive - because it's about more than just 1 unit, it's about the shop, materials, methods and procedures.  For example, LEX, TMB ProPower, Indu, Whirlwind, Motion Labs... all have UL-Listed shops and they spend a whole bunch of $$ getting those Listings (far more than for just 1 product) so they can build a variety of designs, not just 1 or 2 products.

JR designed a nifty little outlet tester that could detect RPBG (reversed polarity, bootleg ground) Edison outlet wiring.  It was a simple device with about 6 components.  It was going to cost over $10k to get it UL Listed.
More than 6 components but indeed UL is a profit making business. I had to pay them hundreds of dollars just to buy a copy of the applicable UL spec (that I can't share). Then thousands of dollars to wrestle with them, all for a SKU that should retail for less than my BOM cost to compete with crap 3 lamp testers.

Not only does UL need to vet the design, but they even inspect/certify the factory where it is built to insure that the design is accurately assembled to plan, using approved components.

JR 
Quote
While I don't recall hearing about any recent electrical fires or personal injuries from "lesser" distros, the NFPA 70 committee has been tightening the standards for portable switchboards over the last couple of Code cycles.  They seem to think there are still some shady and potentially dangerous portable AC systems out there.

If your locale has not adopted the most recent Codes you *might* get away with a home-brew distro for awhile.  Your chances of being inspected are proportional to the level of events you do:  working bars and clubs means you'll probably never see an inspector but doing county fairs, municipal events, anything with temporary demountable entertainment structures (stages and roofs) significantly increase the likelihood of inspector visits.
Title: Re: Electrical codes in building DIY distro?
Post by: Jamin Lynch on October 02, 2019, 12:15:32 pm
What about one of these?
Title: Re: Electrical codes in building DIY distro?
Post by: Jeff Bankston on October 02, 2019, 03:17:42 pm
What about one of these?
I use those spider boxes to plug the guitar amps and keyboards into.
Title: Re: Electrical codes in building DIY distro?
Post by: Rob Spence on October 02, 2019, 05:24:56 pm
I wonder if the NEC was really after the crappy hotel ballroom home brew distros? Every one I have seen made me squirm.
Title: Sketchy distro?
Post by: Mike Monte on October 02, 2019, 08:51:47 pm
I wonder if the NEC was really after the crappy hotel ballroom home brew distros? Every one I have seen made me squirm.

I gigged this past Saturday at a club that has live bands Friday/Saturday nights.
The installed(?) distro looked sketchy to say the least; a wooden box on the floor with five quad break out boxes (four 15A edisons per breakout box).
I should have taken a picture....but it wasn't my rig, so I gave it little thought.
(I've see these before in hole-in-the-wall places but usually they are mounted on a wall....not on the floor "begging to have beer dumped on it...".)

I did, however, stay well-back from mic while playing my sax...  You never know...



Title: Re: Electrical codes in building DIY distro?
Post by: Sam Saponaro Jr on October 02, 2019, 10:09:58 pm
Yea last code update for me was 1996 NEC so I did not know all this has changed so much. I'm just getting royaly sick of running 12ga cables everywere searching for circuits in venues. FYI for those with no distro start heading toward the clubs kitchen theres allways circuits in there LOL