# Getting power? 50 Amps?



## Charc (Jun 11, 2007)

I was just pondering how you guys set-up for gigs or the such, for example some kind of reception or event in ballroom or something. (Okay my examples are terrible. What I mean is, let's say you gotta do something, all rented gear. Where do you plug in your gear? Presumably you won't be using 3-4 20amp circuits. Can you guys go to some kind of panel where they might have some kind of industrial receptacle, for, I don't know, say 60 amps? That's respectable for a small gig, right? Just curious what the custom is for these types of gigs, and getting power for them.

Charlie


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## soundman (Jun 11, 2007)

If the venue was built for events it should have a company switch (or 6). A company switch is a place for road shows (or one offs) to get power. When refereeing to a company switch it is understood that it’s 3 phase power. Think of it as a big breaker that the show can tie into. The two main ways to tie in are Cam Loks and bare ends. Cam loks are high amperage plugs (up to 400 amps each phase) and bare ends are just that. 

If the venue dosn't have a company switch most people head to the kitchen and try and find some high amperage service lines to plug into.

Becasue everyone likes pictures http://www.unionconnector.com/cswitch/gallery.html


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## stantonsound (Jun 11, 2007)

Depending on the hotel, convention center, event hall, etc... you have no idea what you are going to get. Most hotels have a 60 or 100 amp panel that is mounted on a piece of plywood and has receptacles mounted all around it. They are 2 or 3 phase, and each receptacle is usually a 20amp circuit. they plug in to a plug that often looks like a big clothes dryer plug.

Others will use a twistloc plug system, usually a L620 (or many call it a 2120) system with "dog houses", which have a set of standard 20amp plugs on them.

Few will have actual "lug" power. These are usually available in 200 or 400 amp services. These are not common in smaller venues, but common in large.

Don't forget, it costs money to tap into these. A recent hotel job that I did cost me $450 for a 60 amp service. Lug power at the LasVegas Convention Center is about $1200 per day. 

To be flexible, I used to have a 12 channel, 1.2k dimmer rack that was wired to 6 edison plugs. It allowed me to plug them into the three phase systems that I usually get, with one into it's each 20amp circuit. I just sold this on ebay and bought two of the Leprecon ULD dimmer packs. 

To be honest, it will be different at each venue.


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## zac850 (Jun 11, 2007)

As was said, usually there is a wonderful panel all ready to be tied into, just need some sort of Power Distro system and your ready to go (well, assuming you or someone else are qualified to do the tie in).

If no company switch, go look for the breaker boxes, figure out what is where, figure out how much is free. Go get the electrical drawings for the space, figure out what panel has enough unused power in it.

I had to do something like this for a show I recently did. The wig and makeup department needed 16kw of power for hair dryers and whatever else wig and makeup people use. We ended up finding an unused panel in the basement of the theater, checked the blue prints, found where it was run to, decided that it was indeed safe, and tied a small sensor rack with non-dim cards into the panel (it happened to be single phase, so we had to switch the sensor rack to single phase). From there we ran one multi cable up to where wig and makeup needed the power.


I've also done shows scrounging 20 amp outlets around, figuring out what is tied to what, taping up extra outlets so no one tries to plug anything else into them........... but that sound be avoided if at all possible.


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## stantonsound (Jun 11, 2007)

Generator power is really not as expensive of an option as you would think. I have rented the big caterpillar trailer generators for a few shows. To be honest, if you are charged for power at the venue and need to hire an electrician to tap into a panel, it is probably cheaper.


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## Van (Jun 11, 2007)

Stanton is correct. Sometimes you have to pay a flat rate for a "tie-in". let's say $6-12 / amp < it's sort of a sliding scale> so at times getting a generator < jenny> is a lot cheaper, even if you do have to pay a babysitter. Convention centers, meeting facilities will almost always have as others have stated, Hubbel, Cam-Lok, or L120 plugs availible. If not, Break out the sniffer and start looking for dedicated circuits.


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## Charc (Jun 11, 2007)

I just wanted to take a moment here to publicly kick myself.
As I mentioned in a previous post I'm in currently reading Gillette's _Designing With Light_ cover-to-cover. The section of the book that explains electrical distribution, company switches, etc. was one page further than my bookmark. Go figure. Maybe I'll read the rest of this book before I post any more?


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## stantonsound (Jun 11, 2007)

Quick story....any mind? Good!
Once upon a time...
I was setting up a pool side Luau for a corporate customer of mine followed by a dance party on the pool deck at the Hilton at Myrtle Beach, SC. I ordered a 100 amp service (it was the biggest they had) for lighting and found 2 open 20 amp circuits for sound. (The band provided sound, we just did the truss and lighting.....the pic is before we raised the truss, the wind was too strong right then to raise the truss just yet) 

We couldn't begin set up until 3pm for an 8pm show, so we had little time to set up. I got there, my guys started putting the truss up and hanging lights, and I put my multimeter on the power distro that they had for me. We had a problem, only one phase had power and I was getting 50volts on the ground and 80 volts on the neutral. I asked to talk to the electrician and we went to the panel room. He had it hooked up very wrong, (I still can't figure out what he did), but the electrical room was under the pool side bar and had more than 8" of water on the floor. He said that it was like this everyday, as the room was below sea level. He was hooking up the cable to the breaker on a hot panel with the front cover off as he was standing on a cinder block that was standing on its ends. It was ridiculous and one of the more unsafe things that I have seen. 
I don't remember the cost of that service, but I think it was about $300 for 100 amps, but it was not 3 phase.


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## Charc (Jun 11, 2007)

stantonsound said:


> Quick story....any mind? Good!
> Once upon a time...
> I was setting up a pool side Luau for a corporate customer of mine followed by a dance party on the pool deck at the Hilton at Myrtle Beach, SC. I ordered a 100 amp service (it was the biggest they had) for lighting and found 2 open 20 amp circuits for sound. (The band provided sound, we just did the truss and lighting.....the pic is before we raised the truss, the wind was too strong right then to raise the truss just yet)
> We couldn't begin set up until 3pm for an 8pm show, so we had little time to set up. I got there, my guys started putting the truss up and hanging lights, and I put my multimeter on the power distro that they had for me. We had a problem, only one phase had power and I was getting 50volts on the ground and 80 volts on the neutral. I asked to talk to the electrician and we went to the panel room. He had it hooked up very wrong, (I still can't figure out what he did), but the electrical room was under the pool side bar and had more than 8" of water on the floor. He said that it was like this everyday, as the room was below sea level. He was hooking up the cable to the breaker on a hot panel with the front cover off as he was standing on a cinder block that was standing on its ends. It was ridiculous and one of the more unsafe things that I have seen.
> I don't remember the cost of that service, but I think it was about $300 for 100 amps, but it was not 3 phase.



Should we assume you are the guy in the background with the lei?

On a serious note, am I the only one that absolutely abhors the look of the aluminum/chrome/silver PAR cans? Too shiny. I'd rather matte black any-day. It does look a little better against the aluminum truss. But I still think it looks "cheap". Or, am I just crazy?

Edit:
Another quick question, that 360Q. Is that a 6x16, or 6x22? I asked this question before, but didn't have an accurate picture, just want to double check.

Edit Edit:
Out of curiosity, as it looks like a stormy day, what is the general procedure for rain and lights outside? You just pull the cords real quick and then lower your gear real quick and try and get it to a dry place, or is it okay in the rain, as long as there is no power, or what?


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## stantonsound (Jun 11, 2007)

This show was September 2004, as the date in July was canceled due to a Hurricane.

Question 1: Fat dude, white shirt, lei on, yup....that's me

Question 2: I love chrome par cans. It isn't rock and roll without them.

Question 3: I believe it was a 6x22. I love using gobos. We had the arches on the building, and a whole bunch of "I'm lovin it" on the pool deck from the truss towers around the pool. There was a red "I'm Lovin It" in the bottom of the pool (note the two leko's with a gold and red gels) I'll post a pic below.

Question 4: It was a little wet. We were using truss mounted dimmer packs. I carry a bunch of the really big zip loc bags (5 gallon?) and put the packs in the bags and hung them under the truss. When I worked big concerts in college (local crew), the techs would power all of the cans, etc... to full before it would start raining and the water would evaporate off. I am not recommending it, but it is what they did. It never really rained, just a sprinkle and overcast.

We used less lighting than was planned due to the wet weather. We didn't use any movers. All told, on the stage we only used:

6 S4 Pars
3 Ellipsoidals
4 Par 64's
8 Par 38's

Then each truss tower had 1 6x12 with a gobo and 2 Par 64's.


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## BillESC (Jun 11, 2007)

Pictures will probably help.
Here is an example of a Company Switch.

Here's a 200a 3 phase distribution box with 24 - 20 amp weatherproof recepticals.

Hope this helps.


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## Charc (Jun 11, 2007)

stantonsound said:


> This show was September 2004, as the date in July was canceled due to a Hurricane.
> Question 1: Fat dude, white shirt, lei on, yup....that's me
> Question 2: I love chrome par cans. It isn't rock and roll without them.
> Question 3: I believe it was a 6x22. I love using gobos. We had the arches on the building, and a whole bunch of "I'm lovin it" on the pool deck from the truss towers around the pool. There was a red "I'm Lovin It" in the bottom of the pool (note the two leko's with a gold and red gels) I'll post a pic below.
> ...



I think I spotted one of the ziploc bags on the right side of the picture. Looks like a great setup. The gobo on the column, from the 6x22 looks like it worked really well, and I bet the red ERS aimed at the pool looked really good too. Nice work. (Nice lei too. )


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## Peter (Jun 11, 2007)

I'm going to jump in here and remind everyone that power taps like this are right on the edge of electricians territory. My college is great and has installed cam taps in nearly every venue my club works and makes sure they all have proper disconnects, knowing that this is FAR safer than any other way practically available. Doing bare tales or hooking into a panel is something that needs to be done by an electrician, and even cam should only be done once you have been trained on the proper procedure for connecting cam. 

To elaborate abit more about WPI, we are really lucky to have a pair (usually one 120 amp and one ~200 amp) in each of the major venues where we host events. We generally use one for sound and one for lighting to keep things as separate as possible. We also have a firm procedure in place for connecting and checking the connections, as well as warning everyone when the power is turned on and when it is off. With these procedures in place we have had no major incidents with power in recent years!


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## Chris15 (Jun 12, 2007)

And this is where I love being an Aussie. Most of the time, you rock up with your dimmer and plug straight into the conveniently provided 5 pin, 32 amp three phase outlet. 40 or 50 amp outlets also greatfully received. 63 amp are physically much bigger and hence need an adaptor. 10, 15 and 20 amp sockets are physically smaller and also need an adaptor, and careful thought so you don't overload them.

This is a 50 amp Clipsal outlet a la the type in question:


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## Charc (Jun 12, 2007)

Chris15 said:


> And this is where I love being an Aussie. Most of the time, you rock up with your dimmer and plug straight into the conveniently provided 5 pin, 32 amp three phase outlet. 40 or 50 amp outlets also greatfully received. 63 amp are physically much bigger and hence need an adaptor. 10, 15 and 20 amp sockets are physically smaller and also need an adaptor, and careful thought so you don't overload them.
> This is a 50 amp Clipsal outlet a la the type in question:



"A la" the type I'm sure I've never seen before in my life. I don't think we have anything like that over here. The CamLocks (taps?) look like a pretty good option. After finding out more about it though, I do agree with everyone, that this is not something to be tried lightly. I just figured if perhaps it was standard practice to leave 30 amp circuits open anywhere (this sounds stupid now that I write it...) I'd like to find out where...


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## SHARYNF (Jun 12, 2007)

Just to add my .02

Large venues like was said have company switch or disconnect, typically 200 or 400 amps and 3 phase, and as described usually has bare ends or cam loks

Lex makes a very nice three phase 100 amp distro. Be aware that the cost of the feeder cables can be more than the distro.
Generators are great, BUT getting the feed into your venue location and having the subsequent distro to provide these feeds. 

the danger area is that in between when you start looking around for somewhere to plug in. I agree the Kitchen is the usual place to go, BUT you need to be very careful. There are (in the us) still lots of plugs in kitchens typically used for fryers that you will see, problem is a lot of these are three prong plugs. Reason is that typically these devices simply used the two hots, and.... here is where it gets dangerous, some the third is neutral, sometimes it is the ground. Some people will just connect the neutral and the ground together at this point, but again this can be dangerous, since the code is that there should be only ONE point where the ground and neutral are bonded together and that is at the service entrance. A lot of the old timers call these connections the dryer plug ghetto distro connection. ;-)

IMO you are better with a few other options, on is get your self your own disconnect, in the 50 amp area, there are lots of relatively inexpensive spa or pool disconnects, have the disconnnect wired into the panel.

The other option is to buy your self a square d QO or Siemens breaker usually around 60 amps two pole along with your setup, that way if there is not an empty unused breaker in the panel, typically the panel will be one of the two breakers and you can get them to add the breaker into the panel for you and connect you up.

All this is of course typically with venues that are "friendly" to event providers
Sharyn


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## Jezza (Jun 12, 2007)

In reference to the raining/storm question. Where I'm located (northeast) we just crank all the cans up to full and let them bake off the water. Works very well. In one instance we cranked the truss down and wrapped it with plastic because it was one of the old trusses that had dimmer sticks pre-installed and we really didn't want those to get soaked. 

If we think its going to rain, we typically will bag any major connections (feeder, mults, etc) even though they are suposed to be water proof. Any movers that might get wet are typically struck, depending on who the equipment supplier is and how difficult it would be to pull them out of the air.


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## jonhirsh (Jun 12, 2007)

For rain, snow, any precipitation you can just let it evaporate off. This works fine with movers. You just cant power em down till its dry. 

JH


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## Charc (Jun 12, 2007)

Hmmm. The "water-bake-off technique" (if you will), is a pretty ingenious system for keeping your gear dry. The one thing I don't quite understand about that system is, let's say you are trying to light some kind of more intimate dance space at one of these functions; perhaps you are running your fixtures at 40%. It starts to pour, the crowd doesn't care, and continues to dance. You want to save your gear, so you bump up the fixtures to full. Doesn't that kind of ruin the atmosphere you had created? Wouldn't the crowd get angry, if they were having fun, and you started blinding them?

Does the crowd usually run for cover, or do you guys just not care about the crowd anymore?

Just curious.


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## Charc (Jun 13, 2007)

Hmm, again. I was looking at some power distribution systems online, after getting inspired from this thread. I cam across this picture, and I want to take a stab at it, to see if I'm understanding this:



So NEC states that Black is hot, while white is neutral, and green is ground. So in this picture we see the mains connection in the back (normally this is covered by a plate that says "Danger; High Voltage", it's not normally exposed.) So I'll presume that the two rows of receptacles are for, lack of better words two separate "Power Outs". I'll go ahead and guess the not covered green connector is ground. The N must stand for neutral, and all three hot legs (right term?) are sharing a common neutral. So then it looks like three separate hot legs (that can't be right, it sounds too funny) are for... three phase power? (I'm not sure I'm getting the three phase power conceptually.) Other than that I can't think of a reason why you'd need three separate hot legs.

Did I get the rest of that though?


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## avkid (Jun 13, 2007)

Correct, Green is ground(earth)
Let's have a little test.
What do you connect first when tying in with cams?


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## Charc (Jun 13, 2007)

avkid said:


> Correct, Green is ground(earth)
> Let's have a little test.
> What do you connect first when tying in with cams?



Haha, are you insane? I'm no where near qualified to tie in with cams.

For the sake of answering the question, I'm prepared to be hypothetically electrocuted. We'll I'd have to hazard a guess that the first thing I'd connect is the ground, to make sure the hypothetical me is never the path of least resistance.


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## Van (Jun 13, 2007)

charcoaldabs said:


> Haha, are you insane? I'm no where near qualified to tie in with cams.
> 
> For the sake of answering the question, I'm prepared to be hypothetically electrocuted. We'll I'd have to hazard a guess that the first thing I'd connect is the ground, to make sure the hypothetical me is never the path of least resistance.


 
Good guess. Now the cool thing. New Panels like the one you posted a picture of, have an interesting safety interlock. you can't open the little cover till the previous lead is installed. Most < ok, a lot> of the newer disconnects out there also have gone to the new NEMA standard of having 2 < two > neutrals. As you observed earlierin a standard 3 phase camlock panel al three pahases are sharing a common nuetral. This new style panel releives some stress on that circuit. < and sells more cable, camlocs, and panels.> 



In response to one thing mentioned earlier, Peter, This is not "sort of" getting into the realm of a "real" electrician. This is the realm of a real electrician. Tie-ins and disconnects should not be performed by anyone who is not properly trained and licensed. Most state have a MINIMUM requirement of being an LME < limited Maintenance Electrcian> license holder before you can even take the screws out of a panel to do a tie in. In Portland you are "supposed" to be an LME prior to connecting cam-loks into a company switch. Lets make it Very Clear children. Electricity can kill you dead. Even a 60amp sub panel in the woodshop has the ability to roast your eyeballs right outta your skull. As for cam-loks I once lost half of an EDI 48 touring rack because one of my "kids" from the shop decided to help out during an out. She just started disconnecting, the ground first, then the neutral........ Luckily it was only the pack that fried. 
< I hated that pack anyway it weigh 600 pounds.> < But I didn't tell her that!>


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## SHARYNF (Jun 13, 2007)

Many of the installs are now going with a system that will not allow you to open the cap on the cam lok if the system is energized. There is usually a requirement now to have posted right there the proper connect and disconnect sequence.

Van's experience is a classic example of how to have a disaster. NEVER EVER REMOVE THE NEUTRAL FROM A HOT CONNECTION, THE SAME GOES FOR GROUND.

For the sake of education, when connecting, on a standard setup go from right to left, first connecting ground, then neutral then each of the hots, all with the power off.

to disconnect, power off, again typically going from left to right, disconnect each hot, then neutral then ground.

Sharyn


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## Sean (Jun 13, 2007)

SHARYNF said:


> NEVER EVER REMOVE THE NEUTRAL FROM A HOT CONNECTION, THE SAME GOES FOR GROUND.



So, in an example "from the world"....

A 24x2.4kW Sensor Rack and a 6x6kW Sensor Rack tied into a 400amp company switch. Tails to Tees to two short runs of feeder to the two racks. The cables had to be routed under the corner of a showdeck (with the cams right at the upstage edge of the deck--ie, not hidden by the deck).

SOMEHOW, something go put down on the neutral tee, and caused it to rotate just enough that it was completing the circuit but not "locked".

When there would be a lot of traffic at that corner of the deck it would wiggle the connection.

Our first indication that something was wrong was a twofer that melted like a cannon fuse. Then the lights on those racks all stopped working. I started metering power at the racks. At the 6kW rack: L1 to N was giving me ~200v, L2 to N was 60-80v, L3 to N was ~120v. N to G was ~80v. At the other rack things seemed fine, but nothing would turn on.

It took a while to figure out exactly what had happened--tech was still happening around us. 

Disconnecting the neutral is not only VERY dangerous (potentially to people, and apparently twofers!) when the system is energized, it will cause lots of weird things to happen.

--Sean


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## BillESC (Jun 13, 2007)

Jezza,

Do you know John Carver?


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## fredthe (Jun 13, 2007)

SHARYNF said:


> For the sake of education, when connecting, on a standard setup go from right to left, first connecting ground, then neutral then each of the hots, all with the power off.
> to disconnect, power off, again typically going from left to right, disconnect each hot, then neutral then ground.
> Sharyn


I've seen many panels with the gound on the left, so I would disagree that it is "standard" to connect right-to-left
A safer way of putting it might be:

Connecting: Start with the ground, and work accross
Disconnecing: Start at the opposite end from the ground, and work accross, ending with the ground
-Fred


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## Sean (Jun 13, 2007)

fredthe said:


> I've seen many panels with the gound on the left, so I would disagree that it is "standard" to connect right-to-left
> A safer way of putting it might be:
> Connecting: Start with the ground, and work accross
> Disconnecing: Start at the opposite end from the ground, and work accross, ending with the ground
> -Fred



And some gear/boxes have soft tails....

Green/ground is ALWAYS connected first.
Then white/neutral
Then the three hot legs

Disconnect in reverse order. Then the panel layout is irrelevant.

--Sean


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## Sean (Jun 13, 2007)

BillESC said:


> Jezza,
> Do you know John Carver?


Was that directed to me?

No, I don't. Why do you ask?

--Sean


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## avkid (Jun 13, 2007)

Sean said:


> Green/ground is ALWAYS connected first.
> Then white/neutral
> Then the three hot legs
> Disconnect in reverse order.


That's exactly what I was getting at with my earlier "test" question.


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## SHARYNF (Jun 13, 2007)

Sean said:


> And some gear/boxes have soft tails....
> Green/ground is ALWAYS connected first.
> Then white/neutral
> Then the three hot legs
> ...


I agree, my point that I did not make clear was that some of the newer systems have interlocked caps, layout is relevant and forces an order

Sharyn


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## BenFranske (Jun 13, 2007)

A lot of the new company switches I see have no caps but have the connections behind a door (with a feed through on the bottom) which cannot be opened while the switch is on. Another interesting tidbit to remember is that the ground and neutral cams should be reverse gender from the hots so they can't be crossed.


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## BillESC (Jun 13, 2007)

Sean said:


> Was that directed to me?
> No, I don't. Why do you ask?
> --Sean



Nope, I was asking Jezza.

Has anyone come across an old main panel using stick fuses where the neutral also is fused? Happened to me and was a very long two days and a very long story.


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## soundman (Jun 13, 2007)

BenFranske said:


> Another interesting tidbit to remember is that the ground and neutral cams should be reverse gender from the hots so they can't be crossed.



That is up in the air, while it is a good idea in my book this would have to be a universal thing otherwise the amout of adapters needed will make this counter productive. WE are almost done with 3 pin DMX cable after 10 years, the move to flipped G+N might take twice that as the cost per conector is greater.


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## Van (Jun 13, 2007)

BillESC said:


> Nope, I was asking Jezza.
> 
> Has anyone come across an old main panel using stick fuses where the neutral also is fused? Happened to me and was a very long two days and a very long story.


Fused Neutral ? That's Weird! What's the point ? If you fry that leg and you don't fry one of the hot legs, you're goona be in for a world of hurt.


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## Peter (Jun 13, 2007)

Yes, Van, thank you for clarifying that. The only part of this that is not treading into electrician's terratory is the connecting / disconnecting of cam. This can be done by a non-licenced electrician with proper training. 

About the flipped gender ground / neutral, we recently found out that that is quite a standard practice "out west" according to several rental houses and distro manufacturers in our area, and most of the eastern seaboard uses all of one gender on a device. We found this out the hard way when a new distro we ordered came with the ground and neutral's genders reversed. We simply bought two "gender benders" and always keep them with that distro and run the rest of our equipment with all connectors the same gender on any given device.


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## Sean (Jun 13, 2007)

soundman said:


> That is up in the air, while it is a good idea in my book this would have to be a universal thing otherwise the amout of adapters needed will make this counter productive. WE are almost done with 3 pin DMX cable after 10 years, the move to flipped G+N might take twice that as the cost per conector is greater.


It seems to be an East coast/ West coast thing. Most of the lighting gear, on the East coast has H&N reversed. This has been the case for at least 10 years. There are already countless "turnarounds" floating around (and MMF or MFF tees can be used as well). 

--Sean


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## jonhirsh (Jun 13, 2007)

Its more of a rock vs. film thing. 

Rock reverses the G+N because installs are quick. 

Film uses Etape to mark the colours on the legs and does not worry about the colour of the cams. Thus it makes it simpler to not have them reversed. 

JH


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## JD (Jun 13, 2007)

Beware a Floating Delta! Had this in a club in PA once. All three legs measured 120 volts to neutral.. 3 Phase Y right? Nope! A separate feed that handled air, it was a delta box (240 between hots) with no neutral tap on the transformer! (As compared to the tapped delta 120/120/208) When a leg was loaded, it would go to 0 and the remaining legs would go through the roof! (I had to climb the pole outside to figure this one out.) There was a second feed for another mains panel coming in that was standard 3 phase Y (120/120/120 208-208-208) So the tip off was the 120 to ground but 240 between legs and three legs in the box. Only one I ever ran across in 30 years! (BTW, I was using EDI dimmers, they seamed to laugh off the over-voltage! Shame they weigh more than a truck!)
Now, on to "Tapping fees." Never ran into this, even though I did a lot of work down in the Philadelphia theater district. (Schubert, Academy, Forest, etc.) I have to qualify that statement as they were union houses that billed the promoter directly, so there may have been billings I did not know about. Around these parts they are known as "Theatrical Disconnects" for road shows. There were some locations that would charge for a "House Electrician" which was generally the guy that would sit at the bar and watch you do it. My guess is this varies from state to state. The worst were the club owners that would point to 20 amp wall sockets as you were holding camlocks in your hands! Education of venue owners was always the hardest part for me.
To answer some of the questions posted on this thread, Three phase power uses the same size neutral because the power is happening at a different time on each leg with a phase lag between them. With an exactly balanced load, no current flows through the neutral. (This will never happen in real life!) As far as handling power, it's like rigging: If at first you don't succeed, don't do power taps! There is no room for error. 
As far as rain goes, "Danger Will Robinson!" I know, we have all had to do them, but until they invent a 400 amp GFI, it will not be safe. As for the equipment, Cover the moving lights first! They may get wet, work fine, and then three months later fail!


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## Van (Jun 13, 2007)

JD said:


> Beware a Floating Delta! Had this in a club in PA once. All three legs measured 120 volts to neutral.. 3 Phase Y right? Nope! ...................... but until they invent a 400 amp GFI, it will not be safe...........


 

When i was a young know it all, as opposed to now when I'm a Mature know it all, I hooked up a dust collector to a plug in our new shop. Fired up just fine, then I touched it and got the crap knocked out of me. Yup is was an old mechanical warehouse / metal working facility where they used a lot of heavy machinery, all of it delta. FYI now days most good electricians will mark an outlet or switch with a triangle to let others know it is a delta feed and not 3 phase 120. As a good measure, always check every hot to hot, and neutral to hot. They should be 240,240,240,120,120,120, for standard 3 phase 240/120 or 208,208,208,120,120,120 for a 3 phase 208 or motor feed.
Neutral to ground should be 0 if it's anything higher than 12v there is a good possibility that there is a floating nuetral, or reversed nuetral somewhere in the system. 


I actually used a 400 amp gfci for the dive scenes in _Men Of Honor _, Since we were on a dock with a lot of lights and we had folks in the water,around the water etc.etc we had to have this little unit in-line with our Jenny. it was about 2x2x2.5 feet and weighed a ton!


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## beam_1973 (Jun 13, 2007)

Chris15 said:


> 10, 15 and 20 amp sockets are physically smaller and also need an adaptor, and careful thought so you don't overload them.
> This is a 50 amp Clipsal outlet a la the type in question:



I have worked a few Sydney venues where the 3 phase outlet is rated at 20amps, yet the male plug on the end of the dimmer rack cable is remarkably similar to any other one I have seen (that I would assume plugs into a 32 amp 3 phase outlet) with no adaptor present. Is it possible for someone to just rewire the dimmer rack cable with a 3 phase 20 amp plug?

CAC


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## Logos (Jun 13, 2007)

This is a very dangerous statement without actually seeing what you are talking about but I have come across 3 phase outlets with a standard 32 amp socket that have 20amp circuit breakers. This is usually because of supply issues into the building. It would be important to watch your loading of any dimmer rack in that situation.
Normal 15 and 20 amp plugs in Australia are single phase.


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## Edrick (Jun 14, 2007)

400 AMP GFCI 

Atleast according to google.


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## Peter (Jun 14, 2007)

If you want to spend some time browsing lots of power options, check out: http://lexproducts.com I've never bought anything from them, but I have a friend who works there and they have all kinds of power disto stuff that's always fun to look through!


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## Chris15 (Jun 14, 2007)

beam_1973 said:


> I have worked a few Sydney venues where the 3 phase outlet is rated at 20amps, yet the male plug on the end of the dimmer rack cable is remarkably similar to any other one I have seen (that I would assume plugs into a 32 amp 3 phase outlet) with no adaptor present. Is it possible for someone to just rewire the dimmer rack cable with a 3 phase 20 amp plug?
> 
> CAC



Absolutely. Buy the rack unterminated and a quick visit to your electrical wholesaler later you have a 20 amp plug. Then just terminate. The 10-20 amp sets are a smaller diameter than their cousins. But unless you know what you're looking for and have decent light, it would be quite easy to mistake one for the other.

For what it's worth, the adapter in question is a 32 amp socket, a metre or two of flex and a 10, 15 or 20 amp plug. Not some moulded thing since you technically shouldn't be doing this... Oh and I'd be questionable as to whether you could test & tag it as well.


Logos said:


> This is a very dangerous statement without actually seeing what you are talking about but I have come across 3 phase outlets with a standard 32 amp socket that have 20amp circuit breakers. This is usually because of supply issues into the building. It would be important to watch your loading of any dimmer rack in that situation.
> Normal 15 and 20 amp plugs in Australia are single phase.



Err. There are a fair whack of lower amperage 3 phase connections out there. A bowling club might have a 4 pin 10 amp for the green roller. (Happens). Many big motors will use 3 phase because you can get more efficiency out of it and also because reversing is much easier - eg. industrial roller doors, though they don't normally have a plug & socket.

Large cooking appliances are also a sucker for 3 phase, usually 4 pin. Large ovens etc. normally though sometimes cooktops as well - they tend to have neutrals. This is why the kitchen at my old school had a 3 phase 15 amp socket or two. For the teacher's in bench cooktop. Welders are something else where low current three phase can be found (or high current depending)

And then you get the idiots who thought that a 20 amp socket would do in lieu or 32... no comment. At least put the socket in even if you under breaker it. At least I don't need an adapter...


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## JD (Jun 14, 2007)

To help provide clarification, I have attached an image showing the three forms of 3 phase power found in the US that provide 120 volt legs. (Remember, there are other systems in use such as 480v which can not be used without transformers! ) The types shown are Delta, Wye, and Center tapped Delta. Of these, only the Wye (Y) configuration are usable for 3 phase dimmer systems. In these systems, you will find 120 volts between any phase leg to neutral. You will also find 208 volts between any two hot legs. I have found the Center Tapped Delta in many of the older buildings and warehouses I have worked in. Basically, it can be used as a single phase power source. The bottom leg is center tapped providing 120-0-120 volt configuration. (The same as residential power.) WATCH OUT FOR THE THIRD LEG, often called the "Wild Phase", it is 208 volts with respect to neutral. 
The "Floating Delta" is the one that can trip you up. The panel I found in 1983 had a false neutral connected to the ground. It measured 120 from all three phase legs to neutral, and 0 volts from neutral to ground. You will get these readings because there are bleeder resistors (not shown) inside the transformer to drain static. Since your meter does not really place a load on the system, it will appear as Wye. The tip off was 240 volts between each of the hot legs.


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## SHARYNF (Jun 14, 2007)

JD is absolutely correct. The center tapped delta is used in buildings where there is a need for lighting, so that you can have 120 volts, and there is a need for the full 240 volts for equipment, and at the same time for motors there is the three phase delta. It has advantages typically for a placed where the equipment needs the full 240 volts and the 208 causes in effeciencies (heaters and cooking gear etc) It was designed so that you have these three options BUT just as jd said your standard three phase distro should NOT be connected to it.

Three phase y works best for theatrical purposes BUT remember that if you are running 240 volt gear, you will ONLY get 208 volts. 

Sharyn


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## stantonsound (Jun 15, 2007)

Last night I was setting up a show at a very nice hotel in downtown Charlotte, and was using 12 movers. I had requested a 60amp power drop to make sure I had enough power. They provided me with a single phase, 60amp line that had three edison receptacles on it. The problem with this is that there is no real protection from a circuit breaker, as there were no individual circuit breakers for each. It would not trip unless the entire circuit hit 60 amps. The cost for this was $150.

Also, a little off topic, but somewhat related. We were hired to create mood and excitement to the cocktail reception in the pre/post function area. The other lighting company that was there did the main event stage lighting (corporate event). They had a bunch of truss rigged, as well as pipes on the airwall hangers. I was talking to their production director and he said that they were charged a rigging charge to be allowed to hang points. They were charged $50 per point (to rig it themselves - $250 to have the house staff rig it) and $500 flat fee for hanging on the airwall tracks. So, to push the ceiling tile up, and to wrap a spanset or cable around the building steel, it was $50. With the spandex structures, confetti cannons, and other things hanging, there were more than 20 points.


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## jonhirsh (Jun 15, 2007)

$50 is kinda low for that. I know people who have been charged up to 200 per point and 300 to have it done for them. 

JH


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## beam_1973 (Jun 17, 2007)

Logos said:


> but I have come across 3 phase outlets with a standard 32 amp socket that have 20amp circuit breakers. This is usually because of supply issues into the building. It would be important to watch your loading of any dimmer rack in that situation.
> Normal 15 and 20 amp plugs in Australia are single phase.


Hmmm, well the venue in mind has a 3phase socket that is labelled 20amp, so it may just be a diameter difference between it and the 32 amp version I guess. Either way, I still only load to 20amp capacity.

Chris15 said:


> The 10-20 amp sets are a smaller diameter than their cousins. But unless you know what you're looking for and have decent light, it would be quite easy to mistake one for the other.
> And then you get the idiots who thought that a 20 amp socket would do in lieu of 32... no comment. At least put the socket in even if you under breaker it. At least I don't need an adapter...


Ahh, yes, diameter ... that would be it ... thank you. And yes, it would make sense to install a 32 amp socket, label it as 20 amps and breaker it at 20 amps (if that what the actual supply is) ... avoid having to use these adaptors altogether huh! Thanks for the advice!


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## Chris15 (Jun 18, 2007)

beam_1973 said:


> And yes, it would make sense to install a 32 amp socket, label it as 20 amps and breaker it at 20 amps (if that what the actual supply is) ... avoid having to use these adaptors altogether huh! Thanks for the advice!



Now I'm guessing that when you refer to labelled, you're referring to the labels imprinted on the socket itself. These are put there during manufacturing and will be the rated capacity of the socket. These aren't necessarily the breaker ratings. It's like the 1k2 dimmers that show up from time to time. hey are fused at 5 amps, but they've got a 10 amp socket, and the plastic of the socket will still say 10 amps... If that makes more sense. Oh and the diameter difference is only about 10mm between 20 & 32 amp. The outer of a 20 amp plug is pretty close to the diameter of the inner ceramic on a 32 amp socket if that helps visualise it...


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## Radman (Jun 18, 2007)

Back to the order of connect/disconnect, in which order do you connect line/load ends? Line first, then load? Or load then line? Or does it matter?


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## stantonsound (Jun 18, 2007)

If the power is turned off, it shouldn't matter. I personally prefer to connect the cams to the wall, and then to the dimmers. My biggest concern in working with electricity is getting in between the neutral legs. More electricians are injured by getting in between the neutrals than touching the not leads. If I connect to the wall first, I do not have to worry about getting in between the neutrals just in case someone turns it on.

If, on the other hand, the dimmers are far away from the cam/panel and I can not see the switch, I will hook up the dimmer rack first and then hook up the panel. This prevents me from getting injured if someone turns on the power (despite a lock out/tag out).


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## beam_1973 (Jun 19, 2007)

Chris15 said:


> Now I'm guessing that when you refer to labelled, you're referring to the labels imprinted on the socket itself. These are put there during manufacturing and will be the rated capacity of the socket. These aren't necessarily the breaker ratings. It's like the 1k2 dimmers that show up from time to time. hey are fused at 5 amps, but they've got a 10 amp socket, and the plastic of the socket will still say 10 amps... If that makes more sense. Oh and the diameter difference is only about 10mm between 20 & 32 amp. The outer of a 20 amp plug is pretty close to the diameter of the inner ceramic on a 32 amp socket if that helps visualise it...



Chris ... yes and no ... I meant use a 32amp socket (with manufactured label), use a 20amp breaker on it, but install a label above/next to it stating that its only capable of 20amp load (in case breakers aren't immediately next to it, so people don't get confused as to why it might be tripping)

And cool, thanks for the info on the diameter difference between 32 and 20, will help greatly in the future!


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## SHARYNF (Jun 20, 2007)

Just to clarify, the breaker is designed to protect the path from the equipment to the breaker from overload, so the wire, connectors etc is what is being protected, it is NOT the equipment.

Where you can get into problems is when the wire to the socket say is rated for 30 amps, and so it the connector, but the wire that goes from the plug in the socket to the equipment is only rated for 20 amps, you then have a situation where part of the wire could over heat.

Sharyn


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## stantonsound (Jun 20, 2007)

Actually, I was always taught that the breaker is designed to protect YOU from the overloaded circuits, and to prevent a fire. It will prevent damage in most cases for devices like motors, conventional lighting fixtures, and other "heavy duty" devices, but rarely electronic devices such as movers (that is why they have protection built in).


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## Chris15 (Jun 20, 2007)

I think I'm between those two viewpoints... It's there to stop the wiring from overheating and starting an electrical fire for sure. The protection of humans is also an important factor. You short out active and neutral and there is not a safety switch on this planet that will help. But a breaker will trip pronto. Hopefully this will be leading to saving of your life.

Underrated extension leads are also a thing one needs to be careful of. Down here 10 amp is standard and use 1.5mm2 cable. However you also get stuff only rated to 7.5A which uses 0.75mm2 cable. But there is absolutely nothing stopping you from plugging in a 10A load to one of these. Same socket. When the proper cable gets warm under full load sometimes, I'd hate to think what the crappy stuff would do.

Big motors need special breakers so that they don't trip on the inrush current. I believe you would use a D curve breaker in lieu of the standard C curve. And the bottom line in all of this is that a fuse is still much more sensitive and faster acting, but harder to 'reset'.

These things can also play a role in protecting supply components, eg. in dimmers. Over current will cook triacs for instance.


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## stantonsound (Jun 20, 2007)

Here's a few conversions for us yanks that don't understand all that mmsquared stuff.

AWG Cross Sectional Area (mm2)

12 3.31
15 1.65
18 0.82
20 0.52




Anyone else do this??????
Personally, I use 10 gauge 12/3 SO for my 100+' cables. (The real reason is that I got a GREAT deal on 10/3 a while back and bought 1000 feet of it, so I made 100 and 200' cables). It is a little heavier, but I think that it is a little safer and has far less voltage drop for the long runs than the 12/3.


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## Chris15 (Jun 20, 2007)

15 Amp and "heavy duty" are 2.5mm2 cable. Legally you can't have an extension longer than 30m down here = 100' for you lot. Those who make their own cables will sometimes choose to make these long ones in 2.5mm2 cable for voltage drop etc. reasons...


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## SHARYNF (Jun 20, 2007)

stantonsound said:


> Actually, I was always taught that the breaker is designed to protect YOU from the overloaded circuits, and to prevent a fire. It will prevent damage in most cases for devices like motors, conventional lighting fixtures, and other "heavy duty" devices, but rarely electronic devices such as movers (that is why they have protection built in).



GFI's are designed for your protection, but the NEC for standard breakers is just directly for the wire


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## JD (Jun 20, 2007)

Yea, overheating and fire are what the breakers are for. We are now in a changing climate though... GFIC breakers protect against fire, but also look for shock hazard. So far, I have only seen these pop up in panels where there is a water concern, like feeding outlets on parking lot light poles. I have run into a problem with local power at venues that I call "Where's the GFIC?" Often normal outlets are off and the breakers are on. Then you go on a hunt and seek looking for the one GFIC outlet that those outlets are chained onto!


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## Chris15 (Jun 21, 2007)

RCDs by their very design can't help you if you short active neutral, so while electrical codes might say breakers are only there for the wire, in reality, they're not.

Now are you telling me that the norm is not to have your RCDs mounted on the switchboard, rather using the in powerpoint version is normal? Tis the opposite down here. And I'm just beginning to wonder this. When you lot talk about GFCIs, is that exactly what you mean? GFCI = ELCB? ELCB = old. These days we use RCDs that don't need the leakage to be down the Earth wire, which is what you used to need for an ELCB. RCDs run on a core with an active winding, a neutral winding and a trip coil. Get am imbalance between active and neutral and the magnetic fluxes no longer cancel out and the trip coil energises and triggers the relay to cut the power. ELCBs relied on current flow in the earth wire to trip the circuit, which is somewhat less safe. So if your devices are still ELCBs, then you're what 10 years behind the rest of the world...


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## fredthe (Jun 21, 2007)

Chris15 said:


> Now are you telling me that the norm is not to have your RCDs mounted on the switchboard, rather using the in powerpoint version is normal?


In the U.S., Yes.

> And I'm just beginning to wonder this. When you lot talk about GFCIs, is that exactly what you mean? GFCI = ELCB? ELCB = old.


No. Our GFCI is the same as your RCD... they trip on a difference between hot and neutral current. They can even be used where there is no ground connection (such as in refits in old houses), though there are special rules, and they must be properly labeled.


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## len (Jun 21, 2007)

stantonsound said:


> Depending on the hotel, convention center, event hall, etc... you have no idea what you are going to get.



Your best bet is, whenever possible, to visit the site WITH your client AND the site manager and electrician before the event. Specify what the electrical availability is, and if doing a tie-in, who is doing it, where they will do it, where the panel will end up, and WHEN they will do it. Get it in writing and have everyone sign off on it. Then make sure that if the specifications aren't met, it's not your fault and you still get paid. 

In my experience, the bigger the event, the more that can go wrong. Good communication and verification of details is key.


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## stantonsound (Jun 21, 2007)

Good advice, but not practical. From experience, you can not get a site manager or electrician together for a meeting, and the customers are usually from out of town and most of the meetings are done over the phone or via the internet. The customer really doesn't give a crap about electricity or how you get it done, as long as it gets done. They pay you to handle those things, so they don't have to. The on site person that knows the most is always the hardest to get in touch with. There are things like receptacles on the 55th floor on the observation deck that are fed from a panel on the 22nd floor, which also tie into the flag pole lights on the 4th floor. In general, things that just don't make any sense. And as far as signing anything, it is highly unlikely that you can get them to sign anything. It is a CYA thing for them.

I have worked in the same facilities since they were built in some cases, and at least for the past 6-7 years. Things change and there are new problems that arise. Most of the production companies that I know try to keep notes on the facilities. I can tell you where most of the circuits in the ballrooms are, and which theatres in town have company services and what their capacities are (as well as loading dock notes, names of the house electricians/AV companies, etc...). Trying to make friends with the house techs is essential!

The problem is that most larger spaces like these have a contract with an AV or production company (or have house staff if they are a theatre), and they make up their packages significantly as the "In House" company, usually 35+%. The house gets the extra cut. The customers that are smart will hire outside production and in many cases save $10,000+, but the house people do not like it when outsiders come in. I usually hire them as labor, or will have them run video and I will run sound and light, or something like that. It usually helps. So does swag!

(an example, we bid a job at $7,000 and it was not discounted in any way with the going rate for everything. The house bid was over $11,500.)

The other trick is to plug in everything early and power it to full. If something trips, you want it to do so early. It the electrician goes to lunch, or just disappears, you have time to find him before the show starts. Also, they make the circuit tracers, with the tone finders. These are pretty cool and will help some. The show that we had a few weeks ago, we tripped a breaker (someone mistakenly lamped S4 pars with 750's instead of 575's and we were over). No big deal, but it took 5 hours to get the circuit reset. It was behind a locked door and we could not focus until the felt like resetting the breaker. Their work comes first, you are second.


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## SHARYNF (Jun 21, 2007)

For more detailed information on GFCI and how they work
http://www.codecheck.com/gfci_principal.htm

I agree the whole problem of getting the house electrician back can be a royal pain, this is one of the advantages of having your own distro, making sure that you have your own main breaker in the distro feed from the House Switch, this way if you pop a breaker on a branch or overload your main feed, the solution and restart is under your own control. 

Sharyn


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## stantonsound (Jun 21, 2007)

Sharynf....I completely agree. Here is a photo from a recent event. It was in the club level of a professional football stadium. It is daylight so it is a little difficult to see. We had about 40 instruments total, with the ceiling covered with a star gobo and that was the ambient lighting for the room. The nearest distro system was over 500 feet away, so we were limited to the receptacles on hand. We were able to tie into one 60 amp plug where a fryer unit usually plugs in for a concession stand, but that was it. We also had 6 movers, and we lit all of the columns and then stage lighting for the band. 

At this venue, they are GREAT to work with and if we had tripped a breaker, they would have had it fixed in a few minutes.


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## JD (Jun 21, 2007)

stantonsound said:


> Good advice, but not practical.



Hummm... I second that one! During the 80s I toured with rock bands. We always sent a technical rider listing what we needed. I don't think a single venue / promoter ever read them. As for contacting... A little hard to do when you are doing a 90 city 90 day stretch! Most of the time I got a blank stare when asking for the house electrician. Some had disconnects, but most of the time we were on our own. Did a tad under 2000 shows in that decade. Most between 80 and 86. Somehow, we pulled them all off. Not sure how. 

I live a quieter existence now. I am usually renting to the venue or promoter. Its clearly spelled out in our bill/contract what we need, along with a disclaimer noting that any switch / electrician fees are the sole responsibility of the customer. Still getting blank stares. You can try, but often, be prepared to be on your own.


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