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Author Topic: Generator question  (Read 38606 times)

Debbie Dunkley

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Re: Generator question
« Reply #20 on: September 16, 2015, 02:47:13 PM »

Our next show at the same place is next month so I ought to get to the bottom of this before then. I am sure I could get the owner to provide the EU6500 or equivalent but the weight will be a problem possibly. The nice thing about the 3000 is that it is so light compared. If I parallel them, and watch for the first unit running out of gas( which I check periodically during the day anyway), will this cure the grounding issue?w

Edit: as an alternative approach, what about making sure that anything like bass DI (as was mentioned earlier) is connected to the same generator with everything else like lights and miked instruments connected to the other one?
« Last Edit: September 16, 2015, 02:55:51 PM by Debbie Dunkley »
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frank kayser

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Re: Generator question
« Reply #21 on: September 16, 2015, 03:40:19 PM »

<snip>
If I parallel them, and watch for the first unit running out of gas( which I check periodically during the day anyway), will this cure the grounding issue?

Edit: as an alternative approach, what about making sure that anything like bass DI (as was mentioned earlier) is connected to the same generator with everything else like lights and miked instruments connected to the other one?

If you use the Honda generator parallel kit, no worries about grounding. (other than the regular ground-neutral bonding issues with Honda EU series gennies, and the fact that without the G-N bond, a GFCI is useless)  I do not know if the parallel kit for the EU3000 performs the G-N bond...

Trying to ensure completely isolated loads between generators would be a big headache. You'd have to analyze each and every connection in that light, and hope nothing changes, or you start over.  Also, a single pin1 to ground bond in an XLR cable could sabotage your entire isolated load plan.

frank
« Last Edit: September 16, 2015, 03:45:02 PM by frank kayser »
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Kemper Watson

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Re: Generator question
« Reply #22 on: September 16, 2015, 03:50:13 PM »

This is totally out of the league of the OP's system, and likely represents the difference between getting the gig or the entire event being cancelled.

In my part of the country, an EU6500 rents for $135/day, which provides 30A 240V, with 2 20A 120V circuits on the front panel.  It is also under the 10KW limit where a permit and an inspection are required.  The generator you mention would be closer to $800-$1000 with delivery, permitting, inspection, and monkey business.

I run significantly more gear than the OP, and have had no issues on the EU6500.

The MQ 45 is around $400 here. The promoters here always cover the cost
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TJ (Tom) Cornish

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Re: Generator question
« Reply #23 on: September 16, 2015, 04:31:32 PM »

Our next show at the same place is next month so I ought to get to the bottom of this before then. I am sure I could get the owner to provide the EU6500 or equivalent but the weight will be a problem possibly. The nice thing about the 3000 is that it is so light compared. If I parallel them, and watch for the first unit running out of gas( which I check periodically during the day anyway), will this cure the grounding issue?w

Edit: as an alternative approach, what about making sure that anything like bass DI (as was mentioned earlier) is connected to the same generator with everything else like lights and miked instruments connected to the other one?
Debbie, grounding the generators together is as simple as getting a length of green #10 THHN wire from Home Depot as long as the physical distance between your two generators will be, and then attaching this wire between the grounding screws on the generators.  This is very low-cost, and shouldn't raise any eyebrows from inspectors, as it's clear what you're doing.  This is also much easier than trying to keep track of which loads go where.
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TJ (Tom) Cornish

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Re: Generator question
« Reply #24 on: September 16, 2015, 04:36:42 PM »

If you use the Honda generator parallel kit, no worries about grounding. (other than the regular ground-neutral bonding issues with Honda EU series gennies, and the fact that without the G-N bond, a GFCI is useless)  I do not know if the parallel kit for the EU3000 performs the G-N bond...

Trying to ensure completely isolated loads between generators would be a big headache. You'd have to analyze each and every connection in that light, and hope nothing changes, or you start over.  Also, a single pin1 to ground bond in an XLR cable could sabotage your entire isolated load plan.

frank
Frank, the G-N bond becomes problematic with two generators paralleled, as technically both generators need to be bonded to trip the respective breakers.  This effectively turns both generator frames into current-carrying conductors, which may or may not be worse than no bond at all.  This is one of the several reasons a single EU6500 is preferable to a pair of smaller generators.

Phil Graham wrote an article series on generators in entertainment power that is a worthwhile read, though fair warning that things do get a bit technical.  http://www.fohonline.com/current-issue/74-tech-feature/8858-generators-and-portable-primer-part-1.html
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TJ (Tom) Cornish

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Re: Generator question
« Reply #25 on: September 16, 2015, 04:40:16 PM »

The MQ 45 is around $400 here. The promoters here always cover the cost
Which is still 3X the cost of an EU6500/EU7000, and now you're relying on someone else to ensure the generator is delivered and running appropriately - voltage range selection, voltage regulation, phase configuration, etc.  The EU6500 is very difficult to screw up as voltage and frequency regulation is automatic.  The only switch you need to worry about is the 120V or 120V/240V switch, and even then the worst case is it won't work.
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Debbie Dunkley

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Re: Generator question
« Reply #26 on: September 16, 2015, 05:02:13 PM »

Debbie, grounding the generators together is as simple as getting a length of green #10 THHN wire from Home Depot as long as the physical distance between your two generators will be, and then attaching this wire between the grounding screws on the generators.  This is very low-cost, and shouldn't raise any eyebrows from inspectors, as it's clear what you're doing.  This is also much easier than trying to keep track of which loads go where.

I think that is within my capabilities T.J. …LOL……….. thank you.
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Kemper Watson

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Re: Generator question
« Reply #27 on: September 16, 2015, 05:09:08 PM »

Which is still 3X the cost of an EU6500/EU7000, and now you're relying on someone else to ensure the generator is delivered and running appropriately - voltage range selection, voltage regulation, phase configuration, etc.  The EU6500 is very difficult to screw up as voltage and frequency regulation is automatic.  The only switch you need to worry about is the 120V or 120V/240V switch, and even then the worst case is it won't work.

I guess I've been spoiled. Same promoters, same generator providers year in and out.. Never an issue..
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Stephen Kirby

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Re: Generator question
« Reply #28 on: September 16, 2015, 05:13:21 PM »

Debbie, don't know if you remember the days of amps with two wire plugs.  Where you could not only get shocked from the mic but also by brushing into another player who happened to be on the opposite ground reference.

Everything on stage should be at a common ground.  Lights that people can't touch are pushing it.  Having different amps on stage with different grounds is a bad idea.

It seems simpler to have everything on one supply and just let it draw what it does than trying to divide the load between two sources.  I did a couple of outdoor things this summer where there was only two 20A services.  I bonded them together with a poor man's distro but still had to try and work out the loads so that one side didn't get overloaded.  I'm trying to get them to put in a CA outlet so this won't come up.  When these things spill over to the evening and there's no lights they've been lucky nothing bad has happened.  With a decent service we can have lights which will make the event much better.

Edit:  Sodden thought after writing that.  Would running the service from Debbie's two generators to a poor man's distro be okay?  Or does the length of wire create too much current flow?
« Last Edit: September 16, 2015, 05:16:09 PM by Stephen Kirby »
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Art Hays

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Re: Generator question
« Reply #29 on: September 16, 2015, 05:45:05 PM »

I'm a little confused by some previous posts.  Please correct my understanding because I'd love to be more educated about this from people who have practical experience.

From the generator schematics I can't see how paralleling two EU2000's is any different from using one EU6500 other than convenience, e.g. capacity issues and how you draw the loads.  Honda generators don't bond Neutral to Ground.  When you parallel two EU2000's you connect each generator's hot (L1) and neutral (N) together through the parallel cable plug connectors (and the grounds are connected together if you connect this third wire under the screw terminals).

The circuit breakers on each generator still work fine because that are in series with the L1 output.  They respond to the amperage flowing in L1.  Likewise I think a GFCI will still work because it only looks at imbalance between L1 and N.

I could see how if the grounds aren't connected this might affect the inverter electronics sync'ing the phases.
« Last Edit: September 16, 2015, 06:18:25 PM by Art Hays »
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Re: Generator question
« Reply #29 on: September 16, 2015, 05:45:05 PM »


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