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Author Topic: What bad power sources and/or "distros" have you seen?  (Read 9937 times)

Jeff Bankston

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Re: What bad power sources and/or "distros" have you seen?
« Reply #10 on: July 29, 2011, 03:22:56 am »

The only thing scaring me on that is the Ground/Lift switch. I dont see a problem with no breaker on that. It has the 30A hubbel connection coming in whose circuit would be protected by a breaker back at the main distro. This just looks like your power supply for an amp rack. See these all the time.

Paul, I'm not going to be a nice guy. 

DONT GIVE ELECTRICAL ADVICE, YOU ARE WRONG.

I strongly suggest that you go to your local library and read the National Electrical Code (NFPA-70), 2005 or newer edition.  Specifically you need to read and understand Article 200, 210 I and 210 II, 240 and 250; read through 300 to 312, most of it does not apply to our materials or methods but there are things that do; 400 through 408; 520 and 525; and 640.

You have your homework.

Tim Mc

ps. Mike Pyle explains what can happen.  The Code exists to minimize the opportunity for such things.  Electricity is an awesome but fearsome energy.  It can electrocute you or start the fires of hell.  Neither will get you a "good neighbor" recommendation.
+1
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Jeff Bankston

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Re: What bad power sources and/or "distros" have you seen?
« Reply #11 on: July 29, 2011, 03:27:40 am »

!!!
« Last Edit: July 30, 2011, 04:32:31 am by Jeff Harrell »
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Marlow Wilson

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Re: What bad power sources and/or "distros" have you seen?
« Reply #12 on: July 29, 2011, 08:38:20 am »



Not that this is something to joke about, but I love that they used orange outlets (Ie isolated ground outlets).

"but these are hospital grade outlets, what could possibly go wrong".....
i have ordered a many a I.G. outlets for jobs where we installed them in computer server rooms of buildings. if you use an I.G. you must run 2 grounds. a green for the normal ground. a green/yellow stripe for the I.G. and it must be run all the way back to the transformer and terminted to the XO. have you seen the XO ?

I'm familiar with the other applications.  My suspicion is that they were chosen for this distro because they are somehow more 'professional' looking.  PDU's in IT that require an I.G. must include a separate enclosure ground that is absent from the pictured distro as far as I can see.

*I'm not an electrician*
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TJ (Tom) Cornish

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Re: What bad power sources and/or "distros" have you seen?
« Reply #13 on: July 30, 2011, 12:51:06 am »

as one who worked a day job as a commercial journeyman/foreman electrician for a number of years i say you need to first get a copy of the NEC and secondly study books on electrical wiring. "IF" that "outlet setup" in the foto is plugged into a 15 or 20 amp outlet fed by the breaker panel it will trip at 20.01 amps provided its a 20 amp breaker per NEC in commercial buildings.
Or 16 amps, or 60 amps or more, or anywhere in between, depending on the tolerance of that particular breaker, and the length of time the load is on.

This Siemens breaker chart shows that this particular type of breaker won't trip at 2X the rated load for more than 150 seconds:
http://www.sea.siemens.com/us/SiteCollectionDocuments/WSSResources/Internet/Products/110607/110607_18/VL-TCC-EG_806991_525_TM.pdf

Other breaker curves for other products are similar - 20 amps is a nice round rating, but is unlikely exactly the point at which a circuit trips.


15 amp breakers are illegal in commercial buildings. however "IF" those recepticals in the foto are "HARD WIRED" to the panel feeder lugs that is "ILLEGAL"
Pretty much anything hard wired, clamped, taped, etc. to the panel feeder lugs is illegal, other than the panel that is supposed to be there.

and a fire/electro-cution hazard since the wire is not protected. when using a jenny i use spider boxes which have a 50 amp main breaker 5 20 amp recepticles and 1 30 amp 2 pole and each has its own breaker. the foto below is the main switch gear i and 2 helpers installed to power a 9 story building in van nuys cali on van nuys blvd near vanowen st about 6 years ago. there is a lot to know about electrical wiring and TOO many opinions especially from musicians. i'm a drummer and have seen some stuff. my qsc power amps have ground lift straps on the back of them. in a 120 volt circut there are 2 wires. a hot leg and a neutral. the neutral is the return and is grounded in the system at the XO on the transformer in a commercial building. the GREEN wire is an extra ground in case the neutral takes a dump for some way out reason. not everything thats electric has the GREEN extra ground wire. some equipment has a HOT and NEUTRAL(return or ground). you ca get a ground loop caused from having too many grounds and it can cause an amp hum or electric shock.
I'm struggling to know what you mean by some of this - what ground lift straps on your amps are you referring to?  Is this something you fabricated?
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TJ (Tom) Cornish

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Re: What bad power sources and/or "distros" have you seen?
« Reply #14 on: July 30, 2011, 01:10:09 am »

Quote from: Mike Pyle
Assuming they have a 30a breaker on the 30a feeder, that isn't going to stop the 15a & 20a circuits from catching on fire if they are overloaded.
quoting Mike Pyles reply #3 above ^
YES IT WILL ! if that is plugged into or wired directly to a 20 amp breaker
I think you're contradicting what Mike said - since it appears from the photo that this is an L14-30, Mike is assuming this will be plugged into a 30A circuit, which, among other things, creates the problem with the 20A receptacles.


(illegal to install 15 amp breakers in a commercial building per NEC) and 20.01 amps are drawn the breaker SHALL TRIP !
Once again, this sounds nice, but isn't reality.  Breakers trip at a variety of different amperages, depending on the length of time at a particular over-current value.



a circut breaker is designed to protect the wire from overload. a circut breaker is not designed to trip due to a hot leg being grounded BUT they can and "sometimes" do.
The breaker sure better trip if there's a hot to ground short!!  It may not happen instantaneously - see above - but if a breaker fails to break the circuit on a low impedance connection to either ground or neutral, that's a severe failure - potentially lawsuit severe - and not a common one for low current branch circuits.



i have tried tracing wires in buildings buy grounding the HOT leg i want to find the breaker for to the J box only to have it make noise and not trip the breaker.
I'm not sure that's an IBEW approved way of finding a circuit!!


 i am NOT refering to a GFI breaker. #12 THHN2 copper wire in a conduit shall be protected by a 20 amp breaker. i do not recomend hard wiring a cord like in the foto above to a breaker. plugging both those cords into a duplex receptical will trip if the load reaches 20.01 amps. Dan Luckow electric rebuilds and sells circut breakers and if you want to know more about breaker trippage i suggest you contact him. his company is in Chatsworth Ca.
I'm not sure why you're stuck on this being plugged into a 20A circuit - it seems to me that this particular "distro" is a cheap and dangerous way to ensure the user would never blow a breaker in their amp rack, and I suspect it spent much of its dangerous life plugged into 30A outlets. 
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Jeff Bankston

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Re: What bad power sources and/or "distros" have you seen?
« Reply #15 on: July 30, 2011, 01:37:06 am »

!!!
« Last Edit: July 30, 2011, 04:31:44 am by Jeff Harrell »
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BobJohnson

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Re: What bad power sources and/or "distros" have you seen?
« Reply #16 on: July 30, 2011, 02:02:46 am »

This picture I took in Baja in May at a Mother's Day festival with kids all over the place. This was in the back of one of two amp racks. Both looked like the picture though.
Talk about lucky nobody got killed!
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Jeff Bankston

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Re: What bad power sources and/or "distros" have you seen?
« Reply #17 on: July 30, 2011, 02:09:47 am »

!!!
« Last Edit: July 30, 2011, 04:28:05 am by Jeff Harrell »
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Chris Carpenter

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Re: What bad power sources and/or "distros" have you seen?
« Reply #18 on: July 30, 2011, 02:12:12 am »

let me explain some thing to you Tom Cornish > i worked as a commercial electrician for 10 YEARS
...rant...
 call TERRY Purden and ask him about the job i did. Terry is the owner.
I honestly can't tell if you are trolling, or actually serious.
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Jeff Bankston

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Re: What bad power sources and/or "distros" have you seen?
« Reply #19 on: July 30, 2011, 02:14:37 am »

!!!
« Last Edit: July 30, 2011, 04:25:17 am by Jeff Harrell »
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ProSoundWeb Community

Re: What bad power sources and/or "distros" have you seen?
« Reply #19 on: July 30, 2011, 02:14:37 am »


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