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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: Jamin Lynch on September 19, 2013, 10:21:46 am

Title: 50amp outlets
Post by: Jamin Lynch on September 19, 2013, 10:21:46 am
Another issue that often comes up is when the only available power at a venue is an old style 50amp outlet with no ground.

What's a good option to get you safely through the night?

Thanks
Title: Re: 50amp outlets
Post by: RYAN LOUDMUSIC JENKINS on September 19, 2013, 10:49:54 am
Another issue that often comes up is when the only available power at a venue is an old style 50amp outlet with no ground.

What's a good option to get you safely through the night?

Thanks

Are you sure it as no ground or is it no neutral?  In almost 25 years running audio, I have never come across a 50 amp without a ground.  The 50 amp 125/250 volt receptacle does exist in the Nema 10-50R but I have never come across one.  Are you working in some really old venues?   We do have an old hotel here that had a couple 10-30R recepticals that they supossedly were upgrading and may already be done with but no 50s.
Title: Re: 50amp outlets
Post by: Jamin Lynch on September 19, 2013, 11:03:46 am
Are you sure it as no ground or is it no neutral?  In almost 25 years running audio, I have never come across a 50 amp without a ground.  The 50 amp 125/250 volt receptacle does exist in the Nema 10-50R but I have never come across one.  Are you working in some really old venues?   We do have an old hotel here that had a couple 10-30R recepticals that they supossedly were upgrading and may already be done with but no 50s.

Yep. 2 hots and a neutral.



Title: Re: 50amp outlets
Post by: Mike Sokol on September 19, 2013, 11:14:28 am
Another issue that often comes up is when the only available power at a venue is an old style 50amp outlet with no ground.

What's a good option to get you safely through the night?

Thanks

Hmmmm..... I see a lot of 3-wire 30-amp/240-volt dryer outlets with a single ground/neutral contact in older buildings, but I can't remember seeing any 3-wire 50-amp/240-volt outlets in recent memory. But they're entirely possible. Since you're working from a new ground-neutral bonding point, any current on the line conductor will create a voltage drop in that side of the line, which will cause an equal and opposite voltage drop in the neutral conductor. Since your ground wire is also the neutral wire in that case the safety ground voltage will move around a lot, perhaps as much as 10 volts or so.  That suggests you'll want to avoid connecting some of your sound or stage gear to any other receptacles in the building unless you use audio isolation transformers such as a Whirlwind ISO-2 or similar, and you'll certainly want good DI's with a ground lift switch in the "lift" position. If you do cross connect something with shied isolation, lets say the amp rack connected to the 30 or 50-amp/240-volt 3-wire outlet and the mixing console to a handy Edison outlet on the back wall, you'll create a classic ground loop problem and lots of hum. In fact, I think this would be an excellent GLID (Ground Loop Inter-modulation Distortion) situation where power being pulled from the power amp rack will induce 60-Hz ground loop hum that you'll hear only during bass transients (Don't Doubt the GLID). ;D 

So, the basic rule is it. Either EVERYTHING is powered from your own distro connected to this 3-wire, 50-amp/240-volt outlet, or you need to provide audio isolation transformers between gear on the two power feeds. And you might be able to get away with pin-1 lifts on the XLR inputs depending on the CMRR of your balanced inputs on the amp rack. But I personally would avoid cross connecting gear powered between standard Edison wall outlets and your 3-wire distro in general. Too many things to go wrong.   
Title: Re: 50amp outlets
Post by: Mike Sokol on September 19, 2013, 11:50:47 am
Yep. 2 hots and a neutral.
Note that the neutral is also the ground as well. So you have a double-bonded G-N in your power system.
Title: Re: 50amp outlets
Post by: Steve M Smith on September 19, 2013, 01:19:36 pm
You Americans certainly have a strange assortment of power outlets!


Steve.
Title: Re: 50amp outlets
Post by: Rob Spence on September 19, 2013, 02:18:24 pm
Are you sure it as no ground or is it no neutral?  In almost 25 years running audio, I have never come across a 50 amp without a ground.  The 50 amp 125/250 volt receptacle does exist in the Nema 10-50R but I have never come across one.  Are you working in some really old venues?   We do have an old hotel here that had a couple 10-30R recepticals that they supossedly were upgrading and may already be done with but no 50s.

I did a gig a few years back that had a 10-50R next to a sub panel. I made them replace it with a 14-50R before I would use it (discovered weeks before the gig).

My electric range came with a 10-50P on it. I had the cord set replaced before I could use it.

They are pretty common up here in the northeast. Of course, all newer construction has the 4 wire versions.



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Title: Re: 50amp outlets
Post by: Mike Sokol on September 19, 2013, 03:42:41 pm
You Americans certainly have a strange assortment of power outlets!
Steve.

Yes we do. I've worked for a British sound company here in the US for 20 years, and always laughed at our US power outlets.
Title: Re: 50amp outlets
Post by: Jonathan Johnson on September 19, 2013, 03:58:30 pm
Yep. 2 hots and a neutral.

(http://forums.prosoundweb.com/index.php?action=dlattach;topic=146139.0;attach=9000;image)

This is a typical older style range receptacle conforming to the NEMA 10-50 spec. You'll notice that right on the front, it says "50A 125/250V" and "NEMA 10-50R."  In the typical application with a slide-in kitchen range, the neutral (the lower, vertical slot in this picture) is actually a shared neutral/ground, and the chassis of the range is bonded at the range's terminal block to the neutral+ground wire in the cordset. (Note that the NEMA 10-30 used to be used for clothes dryers similarly to ranges; this has been replaced with the NEMA 14-30.)

Current electrical code does not permit this style of plug to be used anymore; for new construction, your kitchen range must use a NEMA 14-50 receptacle and plug which provides separate neutral and ground contacts.

Here's a useful chart (courtesy Wikimedia) which applies to North America:

(http://upload.wikimedia.org/wikipedia/commons/2/2a/NEMA_receptacle_pins.svg)
Title: Re: 50amp outlets
Post by: Jonathan Johnson on September 19, 2013, 04:08:44 pm
For high-amperage receptacles (30A or higher) the ground pin is typically installed at the top of the receptacle as most cordsets with right-angle plugs will have the ground pin opposite the cord entrance.

That's a fancy way of saying "so the cord be hangin' down."

For 20A and 15A receptacles, the debates for whether the ground pin should be up ("safety!") or down ("my wife says it needs to look like a face!") are endless. To my knowledge, the National Electrical Code gives no requirements for receptacle orientation.
Title: Re: 50amp outlets
Post by: Steve M Smith on September 19, 2013, 04:16:50 pm
In houses here in the UK you will only find one outlet now and that is the standard 13A socket.  I was surprised to see an outlet for an electric oven in the diagram.  These are always hard wired into their own isolating switch with its own connection back to the consumer unit.

In industrial and entertainment premises, there are standard 16A and 63A sockets.

http://upload.wikimedia.org/wikipedia/commons/4/4c/Mated-16A-Plug-And-Socket.jpg


Steve.
Title: Re: 50amp outlets
Post by: Jonathan Johnson on September 19, 2013, 04:27:07 pm
My electric range came with a 10-50P on it. I had the cord set replaced before I could use it.

When I moved into my current home, the range receptacle was a 10-50R and the clothes dryer was a 10-30R. Rather than replace the cords on the range & dryer (what most people would probably do) I replaced the receptacles for 14-50R and 14-30R, respectively. Safer that way.
Title: Re: 50amp outlets
Post by: John Moore on September 19, 2013, 04:52:47 pm
We will not do an event if the power is not correct, and no ground is a deal breaker. Liability issues and best practices along with sticking to what is right will hopefully prevent and major issue with someone getting shocked, equipment destroyed or damaged. For us it is the right way or no way...
Title: Re: 50amp outlets
Post by: Jonathan Johnson on September 19, 2013, 05:42:36 pm
Tech riders and service contracts should specify the power needs, including the connection the venue shall provide. Failure to provide the requested power should allow you to be released from the agreement, possibly with payment. There should also be a clause that you will not plug in if the power supply is unsafe.

Any wiring that is not in compliance with electrical codes and best practices can be considered unsafe.

This isn't about providing a good show, or about protecting your equipment. It is a life safety issue for you, the performers, the patrons, and anyone else in the vicinity.
Title: Re: 50amp outlets
Post by: Jonathan Johnson on September 21, 2013, 06:40:46 pm
Tech riders and service contracts should specify the power needs, including the connection the venue shall provide.

Some sample text (I am not a lawyer): "(We) reserve the right to have electrical service inspected by a licensed electrician or certified inspector of our choice prior to connection of equipment. Any deficiencies identified during inspection shall be rectified prior to connection."
Title: Re: 50amp outlets
Post by: Jamin Lynch on September 29, 2013, 04:03:05 am
Another issue that often comes up is when the only available power at a venue is an old style 50amp outlet with no ground.

What's a good option to get you safely through the night?

Thanks

Well here ya go.

Did a small town festival yesterday. Pulled up to the stage and I was told power is already hooked up for us. All they need to do is plug it in. Here's what I found. 50amp plug no ground. The cord was about 100ft of 12 gauge SJ cable. There was no other power available. So what do I do? I installed my own set of breakers in the panel next to the plug and called it good. Everything went well.

Title: Re: 50amp outlets
Post by: Scott Wagner on September 29, 2013, 10:12:43 am
Did a small town festival yesterday. Pulled up to the stage and I was told power is already hooked up for us. All they need to do is plug it in. Here's what I found. 50amp plug no ground. The cord was about 100ft of 12 gauge SJ cable. There was no other power available. So what do I do? I installed my own set of breakers in the panel next to the plug and called it good. Everything went well.
...and when the place burns down in a month or two, they'll be naming YOU in the lawsuit.  If you work inside the breaker box, you assume liability.  I'll bet your insurance carrier doesn't cover this, either.
Title: Re: 50amp outlets [o/t swerve]
Post by: Craig Hauber on September 29, 2013, 11:38:33 am
I have one of those plug/recep setups on my kitchen range.  Is it safe to use or should I upgrade it to 4-wire? 
-Why I ask is that there's newer stainless appliances right next to it with proper grounding and was wondering if someone is touching the stove and the fridge at the same time could there ever be an issue?
It's a 1920's house that got rewired in the late 80's (new panel, service entrance and romex for most of the interior wiring)  The existing stove wiring just got re-connected to the new panel. 



Hmmmm..... I see a lot of 3-wire 30-amp/240-volt dryer outlets with a single ground/neutral contact in older buildings, but I can't remember seeing any 3-wire 50-amp/240-volt outlets in recent memory. But they're entirely possible. Since you're working from a new ground-neutral bonding point, any current on the line conductor will create a voltage drop in that side of the line, which will cause an equal and opposite voltage drop in the neutral conductor. Since your ground wire is also the neutral wire in that case the safety ground voltage will move around a lot, perhaps as much as 10 volts or so.  That suggests you'll want to avoid connecting some of your sound or stage gear to any other receptacles in the building unless you use audio isolation transformers such as a Whirlwind ISO-2 or similar, and you'll certainly want good DI's with a ground lift switch in the "lift" position. If you do cross connect something with shied isolation, lets say the amp rack connected to the 30 or 50-amp/240-volt 3-wire outlet and the mixing console to a handy Edison outlet on the back wall, you'll create a classic ground loop problem and lots of hum. In fact, I think this would be an excellent GLID (Ground Loop Inter-modulation Distortion) situation where power being pulled from the power amp rack will induce 60-Hz ground loop hum that you'll hear only during bass transients (Don't Doubt the GLID). ;D 

So, the basic rule is it. Either EVERYTHING is powered from your own distro connected to this 3-wire, 50-amp/240-volt outlet, or you need to provide audio isolation transformers between gear on the two power feeds. And you might be able to get away with pin-1 lifts on the XLR inputs depending on the CMRR of your balanced inputs on the amp rack. But I personally would avoid cross connecting gear powered between standard Edison wall outlets and your 3-wire distro in general. Too many things to go wrong.
Title: Re: 50amp outlets
Post by: Jamin Lynch on September 29, 2013, 11:43:04 am
...and when the place burns down in a month or two, they'll be naming YOU in the lawsuit.  If you work inside the breaker box, you assume liability.  I'll bet your insurance carrier doesn't cover this, either.

Uh....it was outdoors.  How could I burn the place down? If the place was going to "burn down" as you say, it wouldn't happen 2 months from now.

So you would just walk away from this job leaving the hundreds of people out of luck who came to see the bands when there was a SAFE and easy alternative to obtain proper power. Would you prefer I use the plug they had for me? I feel that was way less safe than adding a couple of breakers.
Title: Re: 50amp outlets
Post by: Cailen Waddell on September 29, 2013, 12:45:56 pm

Uh....it was outdoors.  How could I burn the place down? If the place was going to "burn down" as you say, it wouldn't happen 2 months from now.

So you would just walk away from this job leaving the hundreds of people out of luck who came to see the bands when there was a SAFE and easy alternative to obtain proper power. Would you prefer I use the plug they had for me? I feel that was way less safe than adding a couple of breakers.

I believe the point is unless you are a licensed electrician then there was no safe and easy alternative.  My understanding of the world of liability is now that you have touched the inside of the panel, you are responsible for everything connected to it, including that unsafe 50amp connector.  Anything that happens, from electrocution, to electrical fires etc, to that panel from now on is your responsibility until someone else opens it, then it is their problem.

Do you walk away?  I would. In the rare instances when I have needed to do that, electricians would magically appear to fix the problem rather than not have show.  Itsa amazing how a promoter/club owner will do things right when the alternative is no gig/show/party. 
Title: Re: 50amp outlets
Post by: Scott Wagner on September 29, 2013, 12:54:11 pm
Uh....it was outdoors.  How could I burn the place down? If the place was going to "burn down" as you say, it wouldn't happen 2 months from now.

So you would just walk away from this job leaving the hundreds of people out of luck who came to see the bands when there was a SAFE and easy alternative to obtain proper power. Would you prefer I use the plug they had for me? I feel that was way less safe than adding a couple of breakers.
I've done this sort of thing many times, but things have changed with regard to litigation and the concepts of liability.  It's a very different world now.  I would not put my assets at risk in this situation today.  It doesn't matter if any incident happens now or at any time in the future.  Since you decided to open the electrical box and perform work inside, you have now assumed the risk for anything that might happen (now or in the future).  Also, since you've posted this on the internet, the lawyers will most definitely find it.  In the future, get a licensed (and bonded) electrician to perform the work - their insurance will cover this; yours will not.

As for the rest of your questions, fire burns outdoors, too.
Title: Re: 50amp outlets
Post by: Greg_Cameron on September 29, 2013, 03:18:00 pm
50amp plug no ground. The cord was about 100ft of 12 gauge SJ cable. There was no other power available. So what do I do? I installed my own set of breakers in the panel next to the plug and called it good. Everything went well.

Aside from the grounding issues, a 50A plug with 12AWG SJ cord is a big no no if the breaker for that plug was in fact 50A. 20A is the maximum size over-current device for 12AWG wire. And if they were using 4 wire SJ, there's technically a derating for multiple hots in the same jacket. Very dangerous.
Title: Re: 50amp outlets
Post by: Jordan Wolf on September 30, 2013, 07:05:59 am
Well here ya go...
Jamin,

Did you advance the show power situation or talk about generator options with the client?  It seems like there could have been specifics in-place before you arrived.
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 04, 2013, 02:40:50 pm
I've done this sort of thing many times, but things have changed with regard to litigation and the concepts of liability.  It's a very different world now.  I would not put my assets at risk in this situation today.  It doesn't matter if any incident happens now or at any time in the future.  Since you decided to open the electrical box and perform work inside, you have now assumed the risk for anything that might happen (now or in the future).  Also, since you've posted this on the internet, the lawyers will most definitely find it.  In the future, get a licensed (and bonded) electrician to perform the work - their insurance will cover this; yours will not.

As for the rest of your questions, fire burns outdoors, too.

I know for a fact that everything was done safely and correctly so there's nothing for anybody to worry about. The event  was held in a parking lot. Dedicated power pole with it's own meter and breaker panel. Not likely anything could catch on fire then or months down the road.

There was no way to get an electrician out to this little town in the middle of nowhere at 8am. You can ask for generators or electricians in advance, but that doesn't mean you'll get it.

Just about everything we do in this business is dangerous. Stacking speakers, running cords and cables on the floor, lighting trees, ect.  You might as well quit if you're going to worry about lawsuits all the time. Learn from experienced people and use some common sense.
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 04, 2013, 02:43:09 pm
Aside from the grounding issues, a 50A plug with 12AWG SJ cord is a big no no if the breaker for that plug was in fact 50A. 20A is the maximum size over-current device for 12AWG wire. And if they were using 4 wire SJ, there's technically a derating for multiple hots in the same jacket. Very dangerous.

That's why we didn't use it.
Title: Re: 50amp outlets
Post by: Rob Spence on October 04, 2013, 04:09:55 pm
Uh....it was outdoors.  How could I burn the place down? If the place was going to "burn down" as you say, it wouldn't happen 2 months from now.

So you would just walk away from this job leaving the hundreds of people out of luck who came to see the bands when there was a SAFE and easy alternative to obtain proper power. Would you prefer I use the plug they had for me? I feel that was way less safe than adding a couple of breakers.

I would have not waited till show day to KNOW I had safe, correct power.


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Title: Re: 50amp outlets
Post by: Jamin Lynch on October 04, 2013, 04:22:45 pm
I would have not waited till show day to KNOW I had safe, correct power.


Sent from my iPad using Tapatalk HD

 I assume you currently do that for all your events?

OK, So all you guys drive out to every event location in advance no matter how far, inspect the power, get signed contracts and abandon the show if everything in your rider is not met.  I bet not.
Title: Re: 50amp outlets
Post by: Spenser Hamilton on October 04, 2013, 04:25:00 pm
Just about everything we do in this business is dangerous. Stacking speakers, running cords and cables on the floor, lighting trees, ect.  You might as well quit if you're going to worry about lawsuits all the time. Learn from experienced people and use some common sense. Why do something to increase that danger?


Fixed.
Title: Re: 50amp outlets
Post by: Rob Spence on October 04, 2013, 05:00:52 pm
I assume you currently do that for all your events?

OK, So all you guys drive out to every event location in advance no matter how far, inspect the power, get signed contracts and abandon the show if everything in your rider is not met.  I bet not.

If I have not used a venue,
and,
I need more than a couple of outlets,
 then HELL YES, I go visit!
I also bring a long tape measure so I have the right cables.

In the event that the venue is too far to visit, then I want photos from the venue.

I don't like surprises. Uncertainties I can resolve in advance reduce risk at the event.

Sent from my iPad using Tapatalk HD
Title: Re: 50amp outlets
Post by: Cailen Waddell on October 04, 2013, 05:15:50 pm
And yes, I will walk with unsafe power. 
Title: Re: 50amp outlets
Post by: TJ (Tom) Cornish on October 04, 2013, 05:17:32 pm
If I have not used a venue,
and,
I need more than a couple of outlets,
 then HELL YES, I go visit!
I also bring a long tape measure so I have the right cables.

In the event that the venue is too far to visit, then I want photos from the venue.

I don't like surprises. Uncertainties I can resolve in advance reduce risk at the event.

Sent from my iPad using Tapatalk HD
+1 - absolutely.  If I need more than a circuit or two that I'm likely to find around the room, I always advance the show, and distance isn't an excuse.  Get the janitor to whip out his IPhone and take pictures of electric-ey-lookin' things and send them to you.  Yes I write this into my contracts.

This isn't rocket science - either size the power to the show, or size the show to the power.  If you lose a gig because someone is expecting you to do illegal wiring, rigging, pyro, or whatever - that's a win.
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 04, 2013, 07:37:56 pm
And yes, I will walk with unsafe power.

It was only unsafe if we would have used the supplied power......so we didn't......then it was safe.
Title: Re: 50amp outlets
Post by: Cailen Waddell on October 04, 2013, 07:43:51 pm

It was only unsafe if we would have used the supplied power......so we didn't......then it was safe.
Are you a licensed electrician?  If not, what you did was unsafe. I think you probably disagree with me in that. That is certainly your right.
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 04, 2013, 07:55:22 pm
Are you a licensed electrician?  If not, what you did was unsafe. I think you probably disagree with me in that. That is certainly your right.

So all your extension cords, power cables, stringer boxes, lighting cables were all made and/or certified by a licensed electrician? Or did you make them yourself? I don't see a whole lot of difference.

Title: Re: 50amp outlets
Post by: Steve M Smith on October 04, 2013, 08:08:41 pm
Are you a licensed electrician?  If not, what you did was unsafe.

It might be against the rules (or law perhaps) but that doesn't make it unsafe.


Steve.
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 04, 2013, 08:18:38 pm
It might be against the rules (or law perhaps) but that doesn't make it unsafe.


Steve.

Bingo.
Title: Re: 50amp outlets
Post by: Bob Leonard on October 04, 2013, 09:32:19 pm
I did a gig a few years back that had a 10-50R next to a sub panel. I made them replace it with a 14-50R before I would use it (discovered weeks before the gig).

My electric range came with a 10-50P on it. I had the cord set replaced before I could use it.

They are pretty common up here in the northeast. Of course, all newer construction has the 4 wire versions.



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No truer statement than that Rob. My electric range, dryer, and welder all use the same outlet and cord set. Newer construction adheres to the newer code, but there is nothing unsafe about these outlets if properly wired and I see no real need to change them (for these purposes). 250V, neutral, ground, and hot. What's not to like?
Title: Re: 50amp outlets
Post by: Bob Leonard on October 04, 2013, 09:44:25 pm
Aside from the grounding issues, a 50A plug with 12AWG SJ cord is a big no no if the breaker for that plug was in fact 50A. 20A is the maximum size over-current device for 12AWG wire. And if they were using 4 wire SJ, there's technically a derating for multiple hots in the same jacket. Very dangerous.

I don't understand why the big tadoo about these 50 amp outlets. It's a 3 wire grounded circuit carrying 250 volts at (up to) 50A. It's a large version of a 120 volt Edison, it's an outlet that has been in use for about 75 years, and the last time I checked the people in my neighborhood weren't bursting into flames every time they cooked dinner or dried their clothes.
 
I agree with you Greg concerning the smaller #12 cable, however, if a distro using the proper cable and configured with the proper breakers were plugged into one of these sockets I would have no reason to NOT use the outlet as a source.
Title: Re: 50amp outlets
Post by: Bob Leonard on October 04, 2013, 09:49:18 pm
Are you a licensed electrician?  If not, what you did was unsafe. I think you probably disagree with me in that. That is certainly your right.

Cailen,
 
Not wearing a rubber is "unsafe". Properly building a distro or wiring your house without hiring an electrician is NOT "unsafe". I have seen more hack jobs done by electricians then any sound guy who knows he could be killed doing the job wrong. electricians don't have that fear. They tend to feel anything they do is safe, or safe enough to get by.
Title: Re: 50amp outlets
Post by: Cailen Waddell on October 04, 2013, 09:56:06 pm


Cailen,
 
Not wearing a rubber is "unsafe". Properly building a distro or wiring your house without hiring an electrician is NOT "unsafe". I have seen more hack jobs done by electricians then any sound guy who knows he could be killed doing the job wrong. electricians don't have that fear. They tend to feel anything they do is safe, or safe enough to get by.

You are correct. I posted before thinking. I'll revise when I am done with this gig.  I think I meant unsafe in a liability and business sense as opposed to electrically safe.   Regardless I wasn't clear.  Apologies.
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 04, 2013, 09:59:42 pm

I don't understand why the big tadoo about these 50 amp outlets. It's a 3 wire grounded circuit carrying 250 volts at (up to) 50A. It's a large version of a 120 volt Edison, it's an outlet that has been in use for about 75 years, and the last time I checked the people in my neighborhood weren't bursting into flames every time they cooked dinner or dried their clothes.
 
I agree with you Greg concerning the smaller #12 cable, however, if a distro using the proper cable and configured with the proper breakers were plugged into one of these sockets I would have no reason to NOT use the outlet as a source.

It wasn't so much the old style 50amp plug that was the problem, although I didn't really want to plug into it. But if that's all there is and it checked out OK, then we may have used it? We didn't have that type plug with us.  The real unsafe part was more the 100ft 12ga SJ cable we were given. 

At the time all we had was the correct set of breakers, the correct size cord for the job and a store bought, UL listed (not homemade) distro.

Unsafe?? I don't think so.


Title: Re: 50amp outlets
Post by: Jamin Lynch on October 04, 2013, 10:11:14 pm

Cailen,
 
Not wearing a rubber is "unsafe". Properly building a distro or wiring your house without hiring an electrician is NOT "unsafe". I have seen more hack jobs done by electricians then any sound guy who knows he could be killed doing the job wrong. electricians don't have that fear. They tend to feel anything they do is safe, or safe enough to get by.

Thank you Bob. Hit the nail on the head.

I don't know how some electricians around here pass the test!!

Do all you nay sayers really think I'm not going to take every precaution? We use electrical gloves, insulated tools, shut down the main breaker, ect. I don't want to "burn down the building" and loose thousands of dollars of equipment and my income.

It's not unsafe if you do it properly.
Title: Re: 50amp outlets
Post by: Spenser Hamilton on October 04, 2013, 10:51:42 pm
It wasn't so much the old style 50amp plug that was the problem, although I didn't really want to plug into it. But if that's all there is and it checked out OK, then we may have used it? We didn't have that type plug with us.  The real unsafe part was more the 100ft 12ga SJ cable we were given. 

At the time all we had was the correct set of breakers, the correct size cord for the job and a store bought, UL listed (not homemade) distro.

Unsafe?? I don't think so.

I'm sure you did everything to the best of your ability, unfortunately all of your candid rants about hack electricians aren't going to do much to sway an inspector if he happens to find out what you have done - regardless of whether it's a random inspection (which in my experience does happen) or because something went wrong and he is there to investigate an accident.

After spending years doing mobile production where rules are a little... fast and loose, I've spent the last few years as audio technician in a medium-ish sized theatre and my attitude towards standards, safety and liability have changed radically. If something is illegal, regardless of whether or not it is inherently safe, it is treated the same as though it is unsafe. Hell, we reprimanded a stage carp today for straddling the top of a ladder, he didn't get hurt but it is still against best practice and venue policy.

For those in Ontario, look up Entertainment Industry Power Technician and the proposed regulations surrounding it. Times are a changing...
Title: Re: 50amp outlets
Post by: TJ (Tom) Cornish on October 04, 2013, 11:09:27 pm
It might be against the rules (or law perhaps) but that doesn't make it unsafe.


Steve.
You're going to have to talk faster than that to suggest that tying in via breakers is safe. Does the panel cover fit back on?  I'm sure you used a correct knockout, clamp, bushing, strain relief, et al to ensure the cable can't be pulled out?  You de-energize the panel or wear arc-flash gear?  What happens if you happen to bump something and either knock more breakers out, or losen something?

Can lower be temporarily tied in to a service panel in a safe and up to code manner?  Yes. Are there some folks who are not licensed capable of doing this?  Yes.   The fact that there are unqualified licensed electricians is immaterial.   

I don't think I have to go very far out on a limb to say that the vast majority of amateur tie-ins are sub-par, dangerous, and a liability nightmare.

There is more to this than sticking a breaker in a box.
Title: Re: 50amp outlets
Post by: Rob Spence on October 05, 2013, 12:02:22 am
Of course if the OP had advanced the gig, he could have
- asked them to put in a 4 pin connector (heck, I would supply it if it were me)
- or brought a 3 pin to 4 pin adapter cable (maybe not the best solution but...)

In either case he would not have needed to open up the panel and would have saved valuable load in time.

The legal and safety bits are beat to death now.

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Title: Re: 50amp outlets
Post by: Bob Leonard on October 05, 2013, 07:57:53 am
For those who wouldn't know I would tend to trust Rob's best practice concerning electrical anywhere. He's the only person to have ever been to my house, which is 100 years old, and then critique an electrical job I had just finished. The critique? He pointed out an area where I didn't use enough wire staples. I fixed it Rob. ;)
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 05, 2013, 05:24:52 pm
Of course if the OP had advanced the gig, he could have
- asked them to put in a 4 pin connector (heck, I would supply it if it were me)
- or brought a 3 pin to 4 pin adapter cable (maybe not the best solution but...)

In either case he would not have needed to open up the panel and would have saved valuable load in time.

The legal and safety bits are beat to death now.

Sent from my iPad using Tapatalk HD

I really don't have the time to drive out 100 miles to this little town out in the middle of nowhere at $3.00 a gallon to meet with the Priest at the Catholic Church who can barely speak English and who knows nothing about any of this. I just play with the cards I'm dealt and make the best out of the situation.

Bottom line...........Nothing burn down or will burn down. Nobody got hurt. The show went on as scheduled. We are booked again for another festival. I'll most likely do the same thing.

As usual, the topic has strayed totally away from the original post
Title: Re: 50amp outlets
Post by: Tim McCulloch on October 05, 2013, 06:05:12 pm
I really don't have the time to drive out 100 miles to this little town out in the middle of nowhere at $3.00 a gallon to meet with the Priest at the Catholic Church who can barely speak English and who knows nothing about any of this. I just play with the cards I'm dealt and make the best out of the situation.

Bottom line...........Nothing burn down or will burn down. Nobody got hurt. The show went on as scheduled. We are booked again for another festival. I'll most likely do the same thing.

As usual, the topic has strayed totally away from the original post

Those little gigs 100 miles away are the kinds of things that have bit me on the ass over the years.  Any more, I'll make the round trip if there is any doubt in my mind about the load in access or electrical service.

Pictures don't always convey the rate of slope, either.  We had a show where the client said "it's a little raked..." and sent pics.  Yep, it looks like there was a small slope.  We get there... HOLY BatMan, Robin!  Yes, a 14% grade WILL be a problem!  Oh, and the 100 amp electrical service was 5, 20amp Edison receptacles on a 50 amp main breaker...  On a Saturday in rural middle of nowhere.  The show was a success, but that 14% grade made the move out suck in ways that will require years of expensive therapy to forget.  Gas would have been much cheaper. ;)
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 05, 2013, 08:54:32 pm
Those little gigs 100 miles away are the kinds of things that have bit me on the ass over the years.  Any more, I'll make the round trip if there is any doubt in my mind about the load in access or electrical service.

Pictures don't always convey the rate of slope, either.  We had a show where the client said "it's a little raked..." and sent pics.  Yep, it looks like there was a small slope.  We get there... HOLY BatMan, Robin!  Yes, a 14% grade WILL be a problem!  Oh, and the 100 amp electrical service was 5, 20amp Edison receptacles on a 50 amp main breaker...  On a Saturday in rural middle of nowhere.  The show was a success, but that 14% grade made the move out suck in ways that will require years of expensive therapy to forget.  Gas would have been much cheaper. ;)


Wait. What was that one part? "the show was a success".    And you didn't drive over to check it our first, and not everything was just how you wanted it and you made it work somehow? HMMMM
Title: Re: 50amp outlets
Post by: Spenser Hamilton on October 05, 2013, 09:10:57 pm


Wait. What was that one part? "the show was a success".    And you didn't drive over to check it our first, and not everything was just how you wanted it and you made it work somehow? HMMMM

If you are caught performing an illegal tie-in, you will be fined. If someone is hurt because of your illegal tie-in you will likely go to jail.

No amount of sarcastic banter on your part will change that. I hope for your sake that an inspector never comes your way.


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Title: Re: 50amp outlets
Post by: Spenser Hamilton on October 05, 2013, 09:23:29 pm

Oh, and the 100 amp electrical service was 5, 20amp Edison receptacles on a 50 amp main breaker...  On a Saturday in rural middle of nowhere.

What's the matter? 5x20=100, I'm sure the client didn't understand the problem. :p


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Title: Re: 50amp outlets
Post by: Jamin Lynch on October 05, 2013, 09:24:44 pm
If you are caught performing an illegal tie-in, you will be fined. If someone is hurt because of your illegal tie-in you will likely go to jail.

No amount of sarcastic banter on your part will change that. I hope for your sake that an inspector never comes your way.


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No sarcasm. Just pointing out that we always seem to make things work out even when the conditions are not perfect.
Title: Re: 50amp outlets
Post by: Rob Spence on October 06, 2013, 12:01:28 am
No sarcasm. Just pointing out that we always seem to make things work out even when the conditions are not perfect.

Well, at least now you have seen the venue and can have them fix the power before you go back.


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Title: Re: 50amp outlets
Post by: Tim McCulloch on October 06, 2013, 03:26:13 am
No sarcasm. Just pointing out that we always seem to make things work out even when the conditions are not perfect.

I didn't detail what was done and I didn't say how close the show came to not happening.

Do not presume that the show was a success in spite of itself; rather you should know that the client had to call multiple electricians in several communities before finding one who had the circuit breakers, conduit, boxes and misc stuff and could come out and put it all together to provide the service we needed.

IOW, it almost didn't happen.

The manual loading and unloading of our truck into small utility vehicles took hours.  The nice lady from the Chamber of Commerce felt bad that some of her help didn't show up and she decided to crew that day.  By 3pm she was in hospital with heat stroke.

I should not have used the word "success" to describe this event.
Title: Re: 50amp outlets
Post by: TJ (Tom) Cornish on October 06, 2013, 07:11:59 am
I should not have used the word "success" to describe this event.
It seems the event was "completed"; but if I had too many of those "successes", I'd either be in the psych ward, the hospital, or jail.
Title: Re: 50amp outlets
Post by: TJ (Tom) Cornish on October 06, 2013, 07:25:15 am
I really don't have the time to drive out 100 miles to this little town out in the middle of nowhere at $3.00 a gallon to meet with the Priest at the Catholic Church who can barely speak English and who knows nothing about any of this. I just play with the cards I'm dealt and make the best out of the situation.

Bottom line...........Nothing burn down or will burn down. Nobody got hurt. The show went on as scheduled. We are booked again for another festival. I'll most likely do the same thing.

As usual, the topic has strayed totally away from the original post
I'm not sure what kind of badge you keep hoping for with this kind of posting.  "Good job - nobody died today."  "Congrats - your tie-in may be slightly less unsafe than the most idiotic licensed electrician."  "Nice job for saving the client the $300 it would cost to hire an electrician to install a real receptacle, so now they're stuck with everybody and their brother digging in their panel forever."

Nobody on this forum can stop you from doing whatever you want, but what you're doing is illegal and unsafe, and your attitude of "real electricians are idiots and tying in is easy and no big deal" does nothing to help you or anyone else reading these threads or coming to venues you've been to.  Either do it the right way, or at least shut up about it.
Title: Re: 50amp outlets
Post by: Spenser Hamilton on October 06, 2013, 04:27:00 pm
Nobody on this forum can stop you from doing whatever you want, but what you're doing is illegal and unsafe, and your attitude of "real electricians are idiots and tying in is easy and no big deal" does nothing to help you or anyone else reading these threads or coming to venues you've been to.  Either do it the right way, or at least shut up about it.

That is my exact issue Tom, I'm actually quite surprised that there isn't more regulars coming down on this guy. Somebody browsing the forum today, tomorrow or even years from now (I regularly find great advice by searching old threads) needs to know that tie-ins should only be done by a qualified electrician.
Title: Re: 50amp outlets
Post by: Tim McCulloch on October 06, 2013, 05:02:52 pm
That is my exact issue Tom, I'm actually quite surprised that there isn't more regulars coming down on this guy. Somebody browsing the forum today, tomorrow or even years from now (I regularly find great advice by searching old threads) needs to know that tie-ins should only be done by a qualified electrician.

http://etcp.plasa.org/cert_technicians/electricians.html

http://etcp.plasa.org/candidateinfo/electricalexams/ElectricalContentOutline.htm
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 06, 2013, 06:33:13 pm
I'm not sure what kind of badge you keep hoping for with this kind of posting.  "Good job - nobody died today."  "Congrats - your tie-in may be slightly less unsafe than the most idiotic licensed electrician."  "Nice job for saving the client the $300 it would cost to hire an electrician to install a real receptacle, so now they're stuck with everybody and their brother digging in their panel forever."

Nobody on this forum can stop you from doing whatever you want, but what you're doing is illegal and unsafe, and your attitude of "real electricians are idiots and tying in is easy and no big deal" does nothing to help you or anyone else reading these threads or coming to venues you've been to.  Either do it the right way, or at least shut up about it.

I've been trying to end this thing a long time ago but everybody wants to throw a punch, well I'm gonna throw as many as I receive.

OK I get it. You all have made your points...move on.
Title: Re: 50amp outlets
Post by: Jonathan Johnson on October 06, 2013, 09:57:14 pm
Are there people capable of performing electrical work safely and according to code without being a licensed electrician? Absolutely.

Are there licensed electricians who take shortcuts that jeopardize life and property, backed by inspectors that just sign off because they see that electrician's name on the permit? Yup.

Does your ability to perform work safely without license or permit absolve you from liability and protect you from legal action if someone does get hurt on that installation -- even if it's not your fault? Nope, not a chance.

It's simple to put a clause in the contract that says, "Contractor reserves the right to have electrical service inspected by an independent electrician or inspector of his choosing prior to connection to ensure adequacy and safety. Any deficiencies shall be rectified at the venue's/promoter's expense before connection. Failure to rectify deficiencies in a timely fashion will result in cancellation of this contract prior to the event and forfeiture of any deposit paid."

Now that I've summed up this thread, perhaps the admins can lock it. This horse is dead.
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 08, 2013, 05:39:36 pm
Are there people capable of performing electrical work safely and according to code without being a licensed electrician? Absolutely.

Are there licensed electricians who take shortcuts that jeopardize life and property, backed by inspectors that just sign off because they see that electrician's name on the permit? Yup.

Does your ability to perform work safely without license or permit absolve you from liability and protect you from legal action if someone does get hurt on that installation -- even if it's not your fault? Nope, not a chance.

It's simple to put a clause in the contract that says, "Contractor reserves the right to have electrical service inspected by an independent electrician or inspector of his choosing prior to connection to ensure adequacy and safety. Any deficiencies shall be rectified at the venue's/promoter's expense before connection. Failure to rectify deficiencies in a timely fashion will result in cancellation of this contract prior to the event and forfeiture of any deposit paid."

Now that I've summed up this thread, perhaps the admins can lock it. This horse is dead.

I thought this was dead a long time ago, but people gotta just keep repeating the same old thing over again. You didn't say anything different than a bunch have already said before. So you need to let it die. Mike pretty much answered my question a long time ago, everybody else is just bitching.
Title: Re: 50amp outlets
Post by: Adam Whetham on October 21, 2013, 11:17:02 am
Are you sure it as no ground or is it no neutral?  In almost 25 years running audio, I have never come across a 50 amp without a ground.  The 50 amp 125/250 volt receptacle does exist in the Nema 10-50R but I have never come across one.  Are you working in some really old venues?   We do have an old hotel here that had a couple 10-30R recepticals that they supossedly were upgrading and may already be done with but no 50s.

Consider yourself lucky then. They are still scattered everywhere up in the midwest where I'm at. I carry a 14-50 distro, and have had a few places switch their power connection, many still stick with the 10-50R as "everyone else" doesn't have a problem with it. But most of these places also have a ground post next to the receptacle to connect to. It's metered out fine, and I've never had an issue before.

The one I don't carry that I run into every once in a while is a 6-50R. You don't know back woods until this is what they have for you to play in/behind the community center and they unplug the Miller rig for you. (I've had the local town electrician tie in for those, as I carry a 14-50R to tails with me when I'm going somewhere I haven't gone before.
Title: Re: 50amp outlets
Post by: Jonathan Johnson on October 21, 2013, 04:21:56 pm
Consider yourself lucky then. They are still scattered everywhere up in the midwest where I'm at. I carry a 14-50 distro, and have had a few places switch their power connection, many still stick with the 10-50R as "everyone else" doesn't have a problem with it. But most of these places also have a ground post next to the receptacle to connect to. It's metered out fine, and I've never had an issue before.

The one I don't carry that I run into every once in a while is a 6-50R. You don't know back woods until this is what they have for you to play in/behind the community center and they unplug the Miller rig for you. (I've had the local town electrician tie in for those, as I carry a 14-50R to tails with me when I'm going somewhere I haven't gone before.

I was really hoping this thread was dead because of all the back-and-forth bickering over safety and licensing, but since you brought up  NEMA 10-50R, 14-50R, and 6-50R, I though it might be helpful to clarify the difference between these form factors.
As you can see, the big difference between these has to do with how the grounding and neutral conductors are handled. Both NEMA 6-50R and 10-50R receptacles may have implications with audio systems; a NEMA 14-50R receptacle should provide safe, relatively noise-free power distribution providing it is installed correctly.

My preference for distribution would be a 125/250V locking connector, for which there doesn't appear to be a NEMA standard (even though you'll see reference to L14-50, it doesn't appear to be a NEMA designation). I see reference to a "California Standard" CS6364, but I don't know enough about that to speak authoritatively.

In my experience, there are many homes built in the 80's and 90's which have a NEMA 10-50R receptacle installed for the range, but the in-wall wiring includes both a neutral and a grounding conductor. Quite often this was done because the homeowner bought a range and was sold a NEMA 10-50P cordset, or they removed the old NEMA 10-50P cordset from their old range to put on the new one. (The irony is that is is cheaper and easier to replace the cordset with the proper one than replace the receptacle in the wall with the improper one.) In these cases, it's a simple matter to replace the receptacle with a code-compliant NEMA 14-50R receptacle, and replace the pigtail on the range with a NEMA 14-50P cordset, being sure to break the bond between the chassis and the neutral at the range's terminal block. (Same goes for clothes dryers, too -- except you'll use a NEMA 14-30R receptacle and 14-30P cordset.)
Title: Re: 50amp outlets
Post by: Mike Sokol on October 26, 2013, 04:56:31 pm
I was really hoping this thread was dead because of all the back-and-forth bickering over safety and licensing.

I agree. Unless you have something new to add, then let's declare this thread finished.

Title: Re: 50amp outlets
Post by: John Fruits on October 27, 2013, 10:04:10 am
First off, my apologies for posting BUT there seems to be a strange thing going on with forums and 50amp connectors, check out this (now locked) thread at ControlBooth.com.
http://www.controlbooth.com/threads/50amp-hubbell-to-l6-30.33876/
Title: Re: 50amp outlets
Post by: Mike Sokol on October 28, 2013, 07:38:19 pm
First off, my apologies for posting BUT there seems to be a strange thing going on with forums and 50amp connectors, check out this (now locked) thread at ControlBooth.com.
http://www.controlbooth.com/threads/50amp-hubbell-to-l6-30.33876/

WOW! Our own forum seems pretty tame by comparison. At least we keep on topic and avoid name calling.

Title: Re: 50amp outlets
Post by: Spenser Hamilton on October 28, 2013, 07:46:16 pm
WOW! Our own forum seems pretty tame by comparison. At least we keep on topic and avoid name calling.

My new tactic is going to be posting not one, but several, posts without waiting for any response from others. That seems like a good way to get your point across.
Title: Re: 50amp outlets
Post by: Jonathan Johnson on October 29, 2013, 02:03:47 am
WOW! Our own forum seems pretty tame by comparison. At least we keep on topic and avoid name calling.
It's harder to call people names when Your Displayed Name Must Be Your Real Full Name on the left side of the post.
Title: Re: 50amp outlets
Post by: Jamin Lynch on October 29, 2013, 11:48:28 am
WOW! Our own forum seems pretty tame by comparison. At least we keep on topic and avoid name calling.


What? Stay on topic??? "Choke, gag" This is about as far away from the OP as you can get.