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Experience with powering show with Generator


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We have been asked to play an outside show that will be powered by a generator. Does anyone have experience with this? What size generator would I need to power all amps, sound system, and lights? They say that they have 6000watt generator, but I think that that may be way to low in wattage needed?

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We have been asked to play an outside show that will be powered by a generator. Does anyone have experience with this? What size generator would I need to power all amps, sound system, and lights? They say that they have 6000watt generator, but I think that that may be way to low in wattage needed?

 

 

All this depends on what gear you own. You'll have to do a load calculation in order to know. I will say this, small to Medium setup, should be OK, so long as you don't go crazy with lights. Use LED's.

 

Todd A.

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I ran a 7000w FOH with monitors and led lighting on a 6500w generator. It worked but if I had a choice I would rather have had a real genset around 20kw to handle spikes and sag's. The 6500w generator we were using was a really nice. The backline was running off it's own generator of the same model. The client probably paid more renting the 2 small generators than it would have cost for the right one to begin with.

 

Here is a shameless plug for my local guy so you will know what your looking for.

http://www.annapolismobilepower.com/

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I ran a 7000w FOH with monitors and led lighting on a 6500w generator. It worked but if I had a choice I would rather have had a real genset around 20kw to handle spikes and sag's. The 6500w generator we were using was a really nice. The backline was running off it's own generator of the same model. The client probably paid more renting the 2 small generators than it would have cost for the right one to begin with.


Here is a shameless plug for my local guy so you will know what your looking for.

 

 

Are there any safety issues with running multiple Gennies, other than tying the grounds into a ground rod?

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Neutrals must be bonded to grounds, earthed, and the ground system must be bonded together.

 

 

Hmmm.....I thought that most Neutrals were not attached to ground in a Genny System; Honda has a non attached Neutral..

 

From the Hondas EU3000i Manual:

 

"System Ground

Honda portable generators have a system ground that connects the

generator frame components to the ground terminals in the AC output

receptacles. The system ground is not connected to the AC neutral

wire. If the generator is tested with a receptacle tester, it will not show

the same ground circuit condition as for a home receptacle. "

 

Ok, so under that parameter, how does one bond the neutrals? Where is the neutral going in this scenario? Is it floating? Hmmm...

 

Todd

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I'd check to see if the genset provides 6000 continuous watts or only under a peak (surge) load. If it is peak, a continuous rating might be less than 5000 watts. Add the loss from the long extension cords needed to keep the generator noise away from the, well, the generated noises, and you may not have enough capacity.

 

FW

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You were a very lucky guy, go buy a lottery ticket quick!!!

 

 

Ive done it for several times when we had to provide our own power for an event called Bloomsday. The generator was running for 5 to 6 hours at a time, none of the amps were dimed or anything(we're asked not to be over poweringly loud) but the generator didnt stumble, or bog down.

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There should be some Honda application notes regarding required grounding/bonding of portable electrical systems. They fall under the "seperately derived" systems of the National Eloectrical Code as well.

 

 

Yeah, But It's all a Pipe dream. How does one Properly bond a ground in the Playa? Which is dry, slight alkaline, slightly conductive, and almost impossible to drill into? I do bring a monster drill bit and I can drive a Rod 5-6' down. I plan to bring copper this year, in years past I used Rebar. But I realize I have a lot to learn....

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The point it to bond the neutral to ground and earth it as effectively as possible. In a dry environment, every other reference to earth will also have a higher impedance so the net isn't all that different anyway. The desire is that in the event of a fault, the generator frame and the earth and antying attached to the earth will have close to the same potential.

 

The alternative in this instance is to use a GFI on all load ciruits. Then the earth ground is not (as) necessary (for safety).

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You were a lucky guy.


I've done stupid things several times and it turned out ok... I just didn't know how stupid they were or how lucky I was at the time. I do now.

 

 

It not stupid and it wasnt just one time. I live on solar power and deal with generators on a daily basis, the thing that takes the most load is long power cords and/or lots o wiring. We connect it with a short extention cord and dont turn up more than half way. I know what a generator that is overloaded sounds like, this didnt have any problems.

 

It could be that Honda is really lowballing their power estimates or that some of the equipment is really over rating their power(the 450w bass amp is a Behringer and we all know that there's a thing called "Behringer watts" for a reason)

 

I wouldnt recommend doing it, but im just saying that it worked out ok for us, but i tested it before playing the show just to be sure.

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There should be some Honda application notes regarding required grounding/bonding of portable electrical systems. They fall under the "seperately derived" systems of the National Eloectrical Code as well.

 

 

 

Interesting... The DuroPower Genny we have (which is a honda Engine, made by Briggs & stratton) say it's Neutral is Bonded to Ground. Hmmm... Confusing.. One would think there would be some sort of standard here.

 

So in essence, if I do all Sound on One Genny (Duropower 7kW), Ground it with a Set of Grounding Rods (3) driven as far into the Playa as I can (4-6'), kept wet, and then Bond the Neutral and Ground from the EU3000i Genny (Used for Lights), I should be good. All I need to know now is How to do this to code, so I can improve safety from what I already have.

 

Difficult stuff, this electricity.

 

Todd A.

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Yes Todd, and this is the ground/earth reference for everything used at the stage.

 

Honda may have a GFCI built into their output, negating the bonding requirement for seperately derived systems but it's still a good practice IMO.

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It not stupid and it wasnt just one time. I live on solar power and deal with generators on a daily basis, the thing that takes the most load is long power cords and/or lots o wiring. We connect it with a short extention cord and dont turn up more than half way. I know what a generator that is overloaded sounds like, this didnt have any problems.


It could be that Honda is really lowballing their power estimates or that some of the equipment is really over rating their power(the 450w bass amp is a Behringer and we all know that there's a thing called "Behringer watts" for a reason)


I wouldnt recommend doing it, but im just saying that it worked out ok for us, but i tested it before playing the show just to be sure.

 

 

If the extension cords took the most load, you would end up with a smoldering cable. The cable is responsible for some of the loss.

 

What you are not seeing is what is happening to the voltage regulation (including overshoot) of the generator under dynamic conditions. The equipment sees this too and some conditions can damage the equipment. You just aren't aware of what may have been happening internal to the generator that could endanger the audio equipment attached to it.

 

Turning it up "1/2-way" has no bearing on how much power is drawn by the system. It just means that you need twice the drive signal for full power. Another common misconception.

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Yes Todd, and this is the ground/earth reference for everything used at the stage.


Honda may have a GFCI built into their output, negating the bonding requirement for seperately derived systems but it's still a good practice IMO.

 

 

You think adding GFCI to all stage power is a good idea as well? Seems to be on surface. And Yes, Absolutely all grounds on stage lead back to the Genny Grounding Rods. Nothing is floating, and I do not permit any Cheaters whatsoever. I gave a bunch of lectures and have often been seen as a bit of jerk on that front... But I'll take the criticism- in fact happy, so long as the person criticizing me is alive and well to do so.

 

 

and FYI, Main genny isn't a Duropower...it's a Powerboss. I got confused by becasue I have a 3kW Duropower Propane Genny... that died a very quick death out there.

 

 

Lastly... a question for everyone... The Powerboss Genny has an NEMA L14-30. The Genny is capable of 120/240. I've not used this connection, instead I have 4 10Ga. Regular Extension cords. But I would prefer to run that 30amp feed to the amp rack. I'm trying to understand (and the manula isn't clear..) exactly how the power is sent dwon the lines..

 

I get that there are 2 hot lines, each at 120v, a neutral, and ground. The manual states that it can provide the following:

 

"This receptacle powers 120/240 Volt AC, 60 Hz, single

phase loads requiring up to 3,500 watts of power at

29.1 Amps for 120 Volts; 7,000 watts of power (7.0 kW) at

29.1 Amps for 240 Volts.The outlet is protected by a

rocker switch circuit breaker."

 

Now, assuming I buy something like a Furman ACD-100, and ofcourse with the understanding that I have only 29.1amps @ 240 (58.2 @120), would this be recommended? Am I on the correct path? Attach the 250 service to the Furman and I have 3 20Amp Circuits? I'm checking to see if I'm getting this correct or not.

 

Thanks,

 

Todd A.

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GFCI is not a bad thing, but some amps can cause false tripping due to EMI filtering, especially if you have a large number of devices on a circuit. Each one contributes to mains leakage.

 

The L14-30 would feed a distribution panel that breaks out the hot circuits via branch breakers into typical load circuits with a common neutral shared ACROSS phases. This is typical of how all power distribution is accomplished.

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GFCI is not a bad thing, but some amps can cause false tripping due to EMI filtering, especially if you have a large number of devices on a circuit. Each one contributes to mains leakage.


The L14-30 would feed a distribution panel that breaks out the hot circuits via branch breakers into typical load circuits with a common neutral shared ACROSS phases. This is typical of how all power distribution is accomplished.

 

 

OK, This is where my understanding gets hazy... as far as practical approach goes. Does the Furman unit accomplish this? I *think* it does, looking for comfirmation.

 

Tx,

 

Todd

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