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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: Jay Barracato on July 16, 2014, 06:39:30 PM
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Last weekend I refused to let a band roadie (did the setup but didn't mix or anything) use their own stage drops at the front of the stage.
One of the drops I did approve was a Hubbell 4-plex with the low profile plastic box. One I rejected was the same but broken and held together with tape. As he was moving it, the box clearly opened to show the supply wire.
He also has a bunch of metal drops in various states of repair, that I totally refused. My front line in this venue has 12 outlets available as molded tri taps that I pointed out before setup, I never did figure out why that wasn't enough, possibly he was just used to using what they had.
My concerns were based on the height of the stage and the fact that these boxes are easily accessible to the audience. As a matter of fact they are right where people tend to put their drinks, hands, bags and all the other things they find inconvenient to hold in a bar. Audience members were far more likely to come in contact with them than the band members.
The poor condition of many of the cables they had did not leave me confident about the condition of any of them. Rather than checking each cable for safety, a blanket NO was a better answer within our time constraints.
I am still not sure about the Hubbell 4-plex. While a neat idea as a drop they look a bit fragile (or these were really rode hard) and probably need constant checking.
Just a reminder that no matter hold good your power distribution scheme is, someone may walk up and try to set up something that is potentially hazardous.
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I have a bunch of quad boxes with Powercon in/out. One has a gfci in it so anything downstream is also protected.
On a small stage I will put 2 boxes upstage and a couple of power strips with 13' cables (and no off switches) that can be used for pedal boards.
Larger stages get the upstage set and also a downstage set.
I often gaff over house outlets so I know where everyone is getting their power and the whole rig is on one safety ground.
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I have a bunch of quad boxes with Powercon in/out. One has a gfci in it so anything downstream is also protected.
On a small stage I will put 2 boxes upstage and a couple of power strips with 13' cables (and no off switches) that can be used for pedal boards.
Larger stages get the upstage set and also a downstage set.
I often gaff over house outlets so I know where everyone is getting their power and the whole rig is on one safety ground.
I have a bunch of the Whirlwind distro boxes with Powercon In/Out connections which work great. It's also fun to freak out the stage crew who assume they're using Speakon connectors.
I've never thought of gaffing over the house outlets, but that's a great idea. But that won't stop the guest artist from plugging in a guitar amp with an open ground. I find that a quick check with a NCVT like Fluke VoltAlert or Klein NCVT-1 will find a stage amp with a floating chassis from an open ground.
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My front line in this venue has 12 outlets available as molded tri taps that I pointed out before setup, I never did figure out why that wasn't enough, possibly he was just used to using what they had.
It may just be a matter of being familiar with what he already has, although that's no excuse for it being in such poor repair. It's usually the venue outlets that are falling apart after being abused by an endless parade of musicians and their roadies.
Like Rob, I try to use my own distro as much as possible because I know it works and there won't be any unexpected ground loops. And the scariest thing I've seen lately was a muso with his pedal board powered by a Speakon! I mentioned to him that they now have a "proper" connector for doing that. Says he,"Yeah, but if I lose this cable, I can gets the parts to make another ANYWHERE". I guess I can't argue with that logic. ::)
GTD
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The minimum standard you accept ends up being the maximum amount of protection you can rely on.
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And the scariest thing I've seen lately was a muso with his pedal board powered by a Speakon!
I once had a bass player bring his amp into my shop for repair and while I had it opened up noticed that the safety ground wire inside was cut and taped off. So it had an intact ground pin on the power cord that wasn't connected to the chassis. He told me one of this stage crew had done that for him to stop the humming. Assume nothing! ???
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I once had a bass player bring his amp into my shop for repair and while I had it opened up noticed that the safety ground wire inside was cut and taped off. So it had an intact ground pin on the power cord that wasn't connected to the chassis. He told me one of this stage crew had done that for him to stop the humming. Assume nothing! ???
Ain't it grand to have such helpful stage crew who has your best interest at heart? :-\
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And the scariest thing I've seen lately was a muso with his pedal board powered by a Speakon! I mentioned to him that they now have a "proper" connector for doing that. Says he,"Yeah, but if I lose this cable, I can gets the parts to make another ANYWHERE". I guess I can't argue with that logic. ::)
GTD
Along those same lines, one of the scarier things I have seen in the lighting world was an outfit that was using NL-8 connectors as the means to connect their light bars to the dimmer rack. I mean sure, they are rated for 20 Amps per contact, but that doesn't mean it is okay to use them as power connectors!!!
I guess NL-8 connectors are way cheaper than Soco connectors, so he has that going for him.
Good grief... I can't believe some people think this kind of thing is acceptable.
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I guess NL-8 connectors are way cheaper than Soco connectors, so he has that going for him.
"Yeah, but if I lose this cable, I can gets the parts to make another ANYWHERE" Hah!!! ;D
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I mean sure, they are rated for 20 Amps per contact, but that doesn't mean it is okay to use them as power connectors!!!
When I was in Guatemala on a mission trip in 2000, I observed a fluorescent light fixture in a house that was wired with 17AWG galvanized steel electric fence wire. I could've reached up and touched that wire.
My grandmother's house (wired by my grandfather) had a receptacle in the living room that was wired with aerial telephone wire (copper clad steel, maybe 18 AWG, untwisted single pair). Thankfully the only thing ever plugged in was a table lamp. The house has since been completely rewired.
Grandpa's workshop had a receptacle for which the only way to disconnect the power was to either pull the electric meter or cut the wires. There were no switches, fuses, or circuit breakers to get in the way. (Also since rewired.)
Missing and broken coverplates is probably the most common electrical problem you'll see out in the wild. Ironically, it's also the easiest and least expensive to fix; it requires absolutely no training beyond operating a screwdriver.
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Missing and broken coverplates is probably the most common electrical problem you'll see out in the wild. Ironically, it's also the easiest and least expensive to fix; it requires absolutely no training beyond operating a screwdriver.
And when you replace them, you can make sure that the color of the plate matches the rest of the room's decor!! :D
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Missing and broken coverplates is probably the most common electrical problem you'll see out in the wild. Ironically, it's also the easiest and least expensive to fix; it requires absolutely no training beyond operating a screwdriver.
Just don't stick the screwdriver in the outlet. ::)
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Just don't stick the screwdriver in the outlet. ::)
And watch out for RPBG of course...
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For stage drops we use the lex products e strings.... We use powered wedges so find them to be very convenient.
http://www.lexproducts.com/products/entertainment/powerflex-cable-assemblies/multiple-receptacle-extensions/20-amp-e-string-orchestra
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For stage drops we use the lex products e strings.... We use powered wedges so find them to be very convenient.
http://www.lexproducts.com/products/entertainment/powerflex-cable-assemblies/multiple-receptacle-extensions/20-amp-e-string-orchestra
Looks pretty good, but I'm a bit worried about the ground lift adapter that appears to be hanging on a nylon tie near the business end of the assembly. Yes, I know a 2-pin ground adapter is a convenience and customers like it. But, of course, it's a bad/dangerous idea for running active monitors which should be grounded.
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It's not a ground lift. The cable has a 5-20p. The adapter is to 5-15p
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It's not a ground lift. The cable has a 5-20p. The adapter is to 5-15p
Ah yes, now I see it. That's pretty handy. :D
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Looks pretty good, but I'm a bit worried about the ground lift adapter that appears to be hanging on a nylon tie near the business end of the assembly. Yes, I know a 2-pin ground adapter is a convenience and customers like it. But, of course, it's a bad/dangerous idea for running active monitors which should be grounded.
As was pointed out, not a ground lift, but 20a to 15a adapter. I've been using this one for two years now - may not be OA Windsor, but works well and fits my budget ~$100. The LEDs (light green) on each tap are handy to see power status and not too bright as to be a distraction while in use. They have those tethered "weather caps" that I found of little use and are the weak point.
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Why build it with a 5-20 and attach a 5-15 adapter? Doesn't make sense really, but maybe I am being thick headed.
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Because you what the cable to be able to take 20amps, but you know you will often only have 15amp circuits available. The 5-20p would prevent you from plugging into a 15amp only plug, which is silly.
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Why build it with a 5-20 and attach a 5-15 adapter? Doesn't make sense really, but maybe I am being thick headed.
Because you what the cable to be able to take 20amps, but you know you will often only have 15amp circuits available. The 5-20p would prevent you from plugging into a 15amp only plug, which is silly.
I dare say Samuel is right - silly. And no, Stephen, you're not being thick headed. The practical reason is as Samuel states - not too many 5-20 outlets around, it seems.
For example, I know my kitchen is wired 12ga/20amp breaker, but all receptacles are 5-15 (I was under the impression that was a no-no) I don't own anything with a 5-20 plug, and I can't remember seeing any appliance that ever did. Code says to use the proper receptacle based on wire gauge and breaker, but realistically, why bother?
I'm not sure I've seen a 5-20 receptacle at my jobs, except the GFCI devices on the plaza of town. I know I've run my rig off one outlet time and time again. Was it 15 or 20 amp? Dedicated? How much was I really drawing?
The 5-15 plug goes into a 5-20 outlet anyway. And I'm guessing the 5-20 to 5-15 adapter isn't UL listed, either...
I'm guessing that most small operators just plug stuff into a stringer really not knowing the load they're putting on it. They may "know their rig will run on one or two 20 amp circuits". Seems like it's spread'em out, plug'em in, and hope for the best. Some of the more experienced are giving some thought to the load. Others is load it up 'till the voltage sags, or the breaker pops.
Really, how many 1kw class D amps can one put on a 15 amp circuit, anyway?
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Why build it with a 5-20 and attach a 5-15 adapter? Doesn't make sense really, but maybe I am being thick headed.
At first glance, it does seem a bit silly. Since every 5-20 (20A 120V) receptacle accepts a 5-15 plug, why not just put a 5-15 plug on the cord to begin with?
In order to get the 20A rating that is advertised, you can't put a 15A-rated plug on the cord. Even if there is no difference in the electrical properties of the 15A and 20A plugs, and the 15A plug *could* handle 20A of current continuously, the orientation of the prongs determines the rating in the eyes of regulatory, testing, inspection, and standards agencies. Hence the adapter.
As it is, the receptacles on the cordset are rated at only 15A. But when summed together, the total loads could exceed 15A.
In my opinion, every extension cord that is rated lower than the circuit it can connect to should be equipped with a fuse or circuit breaker (as they are in Europe). Many fires have started because someone overloaded a 16AWG extension cord plugged into a 20A circuit -- and the properly sized and functioning circuit breaker never tripped.
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The 5-15 plug goes into a 5-20 outlet anyway. And I'm guessing the 5-20 to 5-15 adapter isn't UL listed, either...
There is no reason why the adapter (5-20R to 5-15P) couldn't be UL listed. The adapter effectively derates the cordset to 15A, but may be designed to be capable of passing 20A safely. However, there could be an issue if it is connected to a 5-15R receptacle on a 20A circuit (a practice permitted in residential and some commercial installations in the US) and the receptacle cannot handle 20A current through the face.
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There is no reason why the adapter (5-20R to 5-15P) couldn't be UL listed. The adapter effectively derates the cordset to 15A, but may be designed to be capable of passing 20A safely. However, there could be an issue if it is connected to a 5-15R receptacle on a 20A circuit (a practice permitted in residential and some commercial installations in the US) and the receptacle cannot handle 20A current through the face.
This whole issue is a code cluster, and stupid, IMO. 5-15 receptacles are virtually always listed as having a 20A pass-through, which is why it's acceptable to use a 5-15R on a 20A breaker (assuming appropriate 12ga wire), since the assumption is that multiple devices will share the load on a circuit.
That is a lame assumption and design; courtesy of grandfathered old systems with 14ga 15A wiring. Assuming that the appropriate OCPD is in place, there's no safety issue attempting to use a device that attempts to draw more than 15A - it's the OCPD's job to protect the wiring, not relying on the load being "nice". The only benefit is possibly saving the user some hassle of having to reset a breaker.
As others have said, there's no electrical capacity difference between the plug - it's just an orientation difference for keying purposes.
All of my cords have 5-15P and 5-20R, and I proudly thumb my nose at this stupid rule.
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FWIW I usually install 20 A receptacles in commercial/industrial situations-unless there are kids around like a church or school, then I use resi TR recepts. If you go to a supply house instead of a big box store, my cost difference between a 15A and 20A Hubbel recpt is 10 cents-and my cost is a third or so of what I would pay for a premium receptacle at a big box-so it might pay to shop if you are building a distro. I know 10 cents a pop can add up-but I like my jobs done a certain way. I once installed cheap big box recepts in a garage downstream of GFCIs. They kept tripping the GFCIs-so I replaced them on my dime and that was the end of the penny pinching!
Actually the NEC permits 15A and 20A recepts on 20A circuits, but only 15A on 15A circuits. Seems odd-but has been that way a long time-likely based on the logic of protecting the installed wiring, external wiring being the users problem.
I doubt there is really any power handling difference between a 15A and a 20A recpt.
Fused cords would be OK-except that people would just over fuse them-the same reason edison fuse boxes are becoming obsolete and are prohibited as new installs.
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There is no reason why the adapter (5-20R to 5-15P) couldn't be UL listed. The adapter effectively derates the cordset to 15A, but may be designed to be capable of passing 20A safely. However, there could be an issue if it is connected to a 5-15R receptacle on a 20A circuit (a practice permitted in residential and some commercial installations in the US) and the receptacle cannot handle 20A current through the face.
True. And this is where your fusing comes into play. The cord is fused at 20a. The adapter is separately fused at 15a.
OT...
How does Europe prevent upsizing of the fuse in the plug - or bypassing the fuse altogether?
This whole issue is a code cluster, and stupid, IMO. 5-15 receptacles are virtually always listed as having a 20A pass-through, which is why it's acceptable to use a 5-15R on a 20A breaker (assuming appropriate 12ga wire), since the assumption is that multiple devices will share the load on a circuit.
That is a lame assumption and design; courtesy of grandfathered old systems with 14ga 15A wiring. Assuming that the appropriate OCPD is in place, there's no safety issue attempting to use a device that attempts to draw more than 15A - it's the OCPD's job to protect the wiring, not relying on the load being "nice". The only benefit is possibly saving the user some hassle of having to reset a breaker.
As others have said, there's no electrical capacity difference between the plug - it's just an orientation difference for keying purposes.
All of my cords have 5-15P and 5-20R, and I proudly thumb my nose at this stupid rule.
mee too... ;)
frank
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When I re-wired my house, I just said screw it and put in 20A receptacles everywhere. I figured I would over-engineer a bit. (And opened up opposite walls in each room from 1-gang to 2-gang outlets- never enough outlets in a bedroom, but not a problem anymore! And pulled datawire throughout. And I think we used 10g wiring for the now-meeting-code 2 "small appliance" circuits in the kitchen, the thought being that some day they could up the requirement, and I had the extra cable to do it with. And outdoor circuits that are now required, but I also did 20A switches on them, so you can turn them off from inside.)
-Ray
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With the other article about the courts placing liability on each member in the power problem I would agree that not accepting the bands poor broken solutions should not be allowed to connect.
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In Ireland/UK alot of these problems are avoided in the residental setting
32amp for a ring main
16amp for a radial spur (not that common)
All household plugs are fused 13amp plugs, and in most of the venues i run sound in, I will run my rig of 1 13amp socket.
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Regarding lampies using NL8 connectors for their AC connections, note the company Selecon who have a range of 80v units. Each lamp comes with a transformer which hangs on the bar next to it, takes a 240v dimmed circuit and outputs 80v to the lamp via NL8.
http://www.seleconlight.com/index.php?option=com_virtuemart&page=shop.product_details&flypage=flypage.p1&category_id=125&product_id=40
Huge savings is power usage I'm told!
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Regarding lampies using NL8 connectors for their AC connections, note the company Selecon who have a range of 80v units. Each lamp comes with a transformer which hangs on the bar next to it, takes a 240v dimmed circuit and outputs 80v to the lamp via NL8.
http://www.seleconlight.com/index.php?option=com_virtuemart&page=shop.product_details&flypage=flypage.p1&category_id=125&product_id=40
Huge savings is power usage I'm told!
That's not a nl8. Either a nl2 or nl4. Not big enough to be an 8.
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That's not a nl8. Either a nl2 or nl4. Not big enough to be an 8.
Nope. It's PowerCon. Part number lifted straight from the specs on the website.
http://www.neutrik.com/en/video/powercon/powercon-20-a/nac3fca (http://www.neutrik.com/en/video/powercon/powercon-20-a/nac3fca)
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Nope. It's PowerCon. Part number lifted straight from the specs on the website.
http://www.neutrik.com/en/video/powercon/powercon-20-a/nac3fca (http://www.neutrik.com/en/video/powercon/powercon-20-a/nac3fca)
Interesting, I wonder where they got the black shells from. I assumed it must be speakon because powercon is supposed to be blue or grey. For the use shown it should be grey...
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Interesting, I wonder where they got the black shells from. I assumed it must be speakon because powercon is supposed to be blue or grey. For the use shown it should be grey...
It is the new series of Powercon. Rated for disconnect/connect under load.
It is not interoperable with the originals.
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Has anyone ever used dimmerrack.com's power supplies? I've seen one of his earlier PD's and it's still going on, but his website is always drawings not photo's of what your getting. Saw a EDM act here recently using blue power con's for 240v. They swore they had no problems with them at all. Stage power is always something to be weary about.. I've seen a deck full of back line go up in smoke, cause the tech wired the five pin backwards..
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I guess NL-8 connectors are way cheaper than Soco connectors, so he has that going for him.
Pet peeve of mine....
Why do Americans always say "Soco" (pronouncing it Sock-Oh)?
The connector was originally called a SocaPex (http://en.wikipedia.org/wiki/Socapex). For God sake, will you please stop saying "Socko"? How did that even start? The correct short form is Soca ("Soak-Ah").
How do these things ever get started?
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Has anyone ever used dimmerrack.com's power supplies? I've seen one of his earlier PD's and it's still going on, but his website is always drawings not photo's of what your getting. Saw a EDM act here recently using blue power con's for 240v. They swore they had no problems with them at all. Stage power is always something to be weary about.. I've seen a deck full of back line go up in smoke, cause the tech wired the five pin backwards..
I believe that the 20A PowerCON connectors are rated for 250 volts.
IIRC, the new style is 16A, but designed to take being connected or disconnected under load. Mark C.
Edit: The new style powerCON ("True 1") is now listed for 20A usage in the USA. Neutrik claims an IP65 rating when connected.
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Pet peeve of mine....
Why do Americans always say "Soco" (pronouncing it Sock-Oh)?
Hey, my British buddies always give me a hard time when I ask for the "saw-dur" instead of "sol-dur" when I'm soldering a connection. I think the Aluminum vs. Aluminium debacle has been covered here already. ;D
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And I suppose it should be "distri" instead if "distro".
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And I suppose it should be "distri" instead if "distro".
touché
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Hey, my British buddies always give me a hard time when I ask for the "saw-dur" instead of "sol-dur" when I'm soldering a connection. I think the Aluminum vs. Aluminium debacle has been covered here already. ;D
Didn't know you could sol-dur al-you-min-ee-um.
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That's not a nl8. Either a nl2 or nl4. Not big enough to be an 8.
It's most certainly not an NL2 or NL4... It's the same physical size as an NL8, but I'll assume it has a different pin configuration.
I'm back in the venue tomorrow so I'll get some photos!
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Didn't know you could sol-dur al-you-min-ee-um.
But the Brits sound so darn intelligent when they say it like that.
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Sure enough... The results are in. The 80v LX units use a standard NL8 speakon connector.
Please excuse the blurry photo! :-)
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Sure enough... The results are in. The 80v LX units use a standard NL8 speakon connector.
Please excuse the blurry photo! :-)
Plenty clear to prove the point...
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Sure enough... The results are in. The 80v LX units use a standard NL8 speakon connector.
Please excuse the blurry photo! :-)
Weird. Their literature says they use PowerCon. Maybe the main input to the power supply unit is PowerCon?
This is definitely an unorthodox use of an NL8
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Weird. Their literature says they use PowerCon. Maybe the main input to the power supply unit is PowerCon?
This is definitely an unorthodox use of an NL8
The Neutrik website shows a 32A version of a powerCON connector that sort of looks like the NL8 body. The NL8 is rated for 30A continuous, but is stated as not suitable for an AC mains connector.
Makes me wonder if a production company might have swapped out the connectors to "simplify cable inventory" or something. I'm not familiar with the line of lighting fixtures, so it is all speculation on my part. Mark C.
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Makes me wonder if a production company might have swapped out the connectors to "simplify cable inventory" or something. I'm not familiar with the line of lighting fixtures, so it is all speculation on my part. Mark C.
It's certainly curious... I can say that the venue doesn't have anything else wired as NL8. All their audio is through other means. Be it Socco or similar!
I'll try find a lamprey who may be able to give some more certain knowledge rather than my speculation!
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The Neutrik website shows a 32A version of a powerCON connector that sort of looks like the NL8 body. The NL8 is rated for 30A continuous, but is stated as not suitable for an AC mains connector.
Makes me wonder if a production company might have swapped out the connectors to "simplify cable inventory" or something. I'm not familiar with the line of lighting fixtures, so it is all speculation on my part. Mark C.
These are original equipment for the lights. I've wired them up when working as a stage hand and thought it odd that they would use a product specifically listed as NOT suitable for their use.
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These are original equipment for the lights. I've wired them up when working as a stage hand and thought it odd that they would use a product specifically listed as NOT suitable for their use.
Too weird. I would not expect that such an OEM use could result in a CE or UL listed fixture. Any idea whether the fixture is listed? If it is listed, I wonder why Neutrik says the connector is not suitable for AC mains useage? Mark C.
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Too weird. I would not expect that such an OEM use could result in a CE or UL listed fixture. Any idea whether the fixture is listed? If it is listed, I wonder why Neutrik says the connector is not suitable for AC mains useage? Mark C.
I remember looking at the cable jacket to see if it was speaker cable, but it was SOxx IIRC. I can't remember if it was 8 conductor or the AWG.
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Too weird. I would not expect that such an OEM use could result in a CE or UL listed fixture. Any idea whether the fixture is listed? If it is listed, I wonder why Neutrik says the connector is not suitable for AC mains useage? Mark C.
Neutrik states that so that people will be less tempted to plug their passive speaker with an NL4 into mains power directly. This is intentional usage keying, not that the Speakon series is unable to handle the power. This 80V light would have the same problem if plugged into 120V power without its power supply.
I suspect they can get away with it because it isn't mains voltage if the transformer steps power down to 80V, and is probably classified as an internal connector to the system.
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I suspect they can get away with it because it isn't mains voltage if the transformer steps power down to 80V, and is probably classified as an internal connector to the system.
Thanks, TJ. The use of a transformer to take it to 80 volts, making it not an AC mains source, is a reasonable explanation for what is being done and why it is OK in context. Mark C.
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Neutrik probably don't want the useage of this connector wandering too far away from speaker connections. If somebody convinces people to use NL8 for line and instrument level connections, were right back to the bad old QTR jack for everything days...
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I was back up in the bridges today pulling our amp racks out of the roof and was able to open up a connector. Standard 8 pins as per usual with four conductors from the plug to the lamp base.
Stupidly didn't take a photo...
But yes, these are purely from the output of the transformer, which hangs on the bar next to the lamp. So the actual cable length is probably three feet.