ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 ... 4 5 [6] 7 8 ... 10   Go Down

Author Topic: Generator question  (Read 38143 times)

RYAN LOUDMUSIC JENKINS

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 609
    • Az Concert Sound Solutions
Re: Generator question
« Reply #50 on: September 21, 2015, 08:17:43 AM »

None of us were there and no one really knows but I think I know the answer and I didn't see any other mentions of it.  I use generators on nearly 90% of my events.  Almost always diesel generators.  In our area we see mostly MQ Power and Airman generators.

The older MQ Power generators had a throttle control knob that you have to pull on and twist to put the throttle control on correctly.  These throttle control features went away several years ago but I still get generators with them every year.

The generators will show 120/240 +/- volts with the throttle control off but as soon as there is a load, the voltage drops significantly.

There's your most likely answer since you don't really have details for us.
Logged

Guy Holt

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: Generator question
« Reply #51 on: September 21, 2015, 06:25:14 PM »

There seems to be some outdated information as well as questions in this thread about the paralleling of the Honda generators.  For instance,

- Honda EU6500is: Generator provides 2 20A 120V circuits on the panel, or with an external distro can provide 30A 120V/240V

Not exactly, out of the box a EU6500 or EU7000 has a continuous load rating (loads lasting more than a half hour) of 5500W and a peak load rating of 6500W and 7000W respectively.  Since in our case, loads run for more than a half hour,  the 30A 240V receptacle on the generator should only provide 23A per leg for an extended period of time.

- Paralleled Honda EU3000is: Provides a 30A 120V receptacle with a pair of EU2000is or a 50A 120V receptacle with a pair of EU3000s.  If you need these larger single circuits, this is your only choice with small generators.


Not exactly, there are other choices.  A 60A Transformer/Distro will step-down the 240V output of an unmodified Honda  EU6500 or EU7000 to a single 46A/120V circuit (see above.)  You can also parallel two EU6500s or EU7000s and use a Transformer/Distro to create a single 100A/120V circuit.

I incorrectly said one could connect two 110v inverter generators and have the option to get 220v (each running 180 deg out of phase from the other). They don't do this- paralleling always connects the two outputs together so they have to be in phase.

Unless you were paralleling two single-phase generators like the EU6500 or EU7000, the result of which is two legs running 180 degrees of phase of one another.

The parallel kits will run the master unit low on fuel before the second unit as they will be loaded in series rather than parallel.  This shortens your run time.
Seems a big disadvantage if they don't each supply 50% to the load when paralleled.

Not only will the generator that picks up the majority of the load run out of fuel quicker, but if the system continues to be loaded, it will also trip it’s breaker before the more lightly loaded generator.  The net result is that you can never fully utilize the generating capacity of the system. For this reason we have engineered a load sharing control into our paralleling control for the Honda EU6500s and EU7000s. 

… don't know how they work their magic, and especially in terms of grounding.  The manual says they have a ground terminal, which connects all metal stuff but is not connected to the generator output.  So you would think that step one is join the frame ground terminals together, "just in case.

The ground terminal does in fact connect all the metal parts of  the generator to the ground pin of the output receptacle.

I tried to learn how paralleling works but couldn't find anything technical

My white paper on the use of portable generators in motion picture production does include a lot of technical information on the operation of the Honda EU6500s and EU7000s in parallel.  It is available at http://www.screenlightandgrip.com/html/emailnewsletter_generators.html#anchorParallelingEU6500s

Guy Holt, Gaffer
ScreenLight & Grip
www.screenlightandgrip.com
« Last Edit: September 21, 2015, 06:29:25 PM by Guy Holt »
Logged

TJ (Tom) Cornish

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4317
  • St. Paul, MN
Re: Generator question
« Reply #52 on: September 21, 2015, 08:37:27 PM »

There seems to be some outdated information as well as questions in this thread about the paralleling of the Honda generators.  For instance,
Quote from: TJ
- Honda EU6500is: Generator provides 2 20A 120V circuits on the panel, or with an external distro can provide 30A 120V/240V
Not exactly, out of the box a EU6500 or EU7000 has a continuous load rating (loads lasting more than a half hour) of 5500W and a peak load rating of 6500W and 7000W respectively.  Since in our case, loads run for more than a half hour,  the 30A 240V receptacle on the generator should only provide 23A per leg for an extended period of time.
 
Guy, with respect, sometimes I wonder if you are trying to be helpful or just pushing your transformer product.  This is an audio forum, and though sometimes loads do contain a lighting component, the vast majority - and I would venture nearly all for a show that would fit on something the size of an EU6500 would be audio loads.  These are dominated by peak draw which is measured in fractions of a second rather than 30 minutes.  It would be great if you would take some time to understand how we work, and not just assume everything is a lighting load.

Quote from: TJ
- Paralleled Honda EU3000is: Provides a 30A 120V receptacle with a pair of EU2000is or a 50A 120V receptacle with a pair of EU3000s.  If you need these larger single circuits, this is your only choice with small generators.
Not exactly, there are other choices.  A 60A Transformer/Distro will step-down the 240V output of an unmodified Honda  EU6500 or EU7000 to a single 46A/120V circuit (see above.)  You can also parallel two EU6500s or EU7000s and use a Transformer/Distro to create a single 100A/120V circuit.
Do you sell a product designed for a pair of EU3000is generators? That's what I was talking about here, and my info comes right from the generator manual.

A 60A distro/transformer deal is fine for a single 120V light source load, which is, I understand, your primary application.  For the typical audio application, running the gear at 240V directly from the generator is even better yet.  It sidesteps your neutral harmonics issue, and the amps are happier, too, not to mention avoiding procuring and hauling another big chunk of iron that will raise inspector's eyebrows.

Unless you were paralleling two single-phase generators like the EU6500 or EU7000, the result of which is two legs running 180 degrees of phase of one another.

Not only will the generator that picks up the majority of the load run out of fuel quicker, but if the system continues to be loaded, it will also trip it’s breaker before the more lightly loaded generator.  The net result is that you can never fully utilize the generating capacity of the system. For this reason we have engineered a load sharing control into our paralleling control for the Honda EU6500s and EU7000s. 

The ground terminal does in fact connect all the metal parts of  the generator to the ground pin of the output receptacle.

My white paper on the use of portable generators in motion picture production does include a lot of technical information on the operation of the Honda EU6500s and EU7000s in parallel.  It is available at http://www.screenlightandgrip.com/html/emailnewsletter_generators.html#anchorParallelingEU6500s

Guy Holt, Gaffer
ScreenLight & Grip
www.screenlightandgrip.com
Logged

Guy Holt

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: Generator question
« Reply #53 on: September 22, 2015, 11:28:09 AM »

I wonder if you are trying to be helpful or just pushing your transformer product.  This is an audio forum, and though sometimes loads do contain a lighting component, the vast majority - and I would venture nearly all for a show that would fit on something the size of an EU6500 would be audio loads. 
 

Just trying to be helpful by correcting a, good intentioned I am sure, incorrect statement.  Though you may not have meant it this way, when you reference the larger 120V circuits that can be obtained by paralleling both EU2000s and EU3000s, you are no longer just talking about paralleling EU3000s , but paralleling small generators in general.  In that context your statement that “this is your only choice with small generators” is false since it is now possible to parallel EU6500s and EU7000s.  Since readers look to this forum for the final word on production technique, I felt it would be a disservice to the readers of this forum to not inform them of new options.  And since the OP was in fact operating lights on the generator, as do many users of small generators in this forum, I think it is relevant to point out the different ratings for peak load verses continuous load for these generators.  Again, it would be a disservice to the OP and other readers to lead them to believe the EU6500/7000 provides 30Amps per leg on the 240V receptacle straight out of the box when in fact it does not.

A 60A distro/transformer deal is fine for a single 120V light source load, which is, I understand, your primary application.  For the typical audio application, running the gear at 240V directly from the generator is even better yet.  It sidesteps your neutral harmonics issue, and the amps are happier, too, not to mention avoiding procuring and hauling another big chunk of iron that will raise inspector's eyebrows.

While operating gear at 240V will minimize neutral harmonics issues, it does not eliminate the voltage waveform distortion described in my previous post.  Better still would be to use only power factor corrected equipment that does not draw harmonic currents in the first place. Not only will equipment operate more reliably on the cleaner power, but you will be able to operate appreciably more equipment on a small generator because power factor corrected equipment is more efficient and you do not have to oversize the generator, i.e. reduce the load, in order to mitigate the adverse effects that harmonic currents can have on small generators.

Since you have now begun to debate the merits of using transformers with small portable generators, I don’t think I can be faulted for responding with what I see to be the advantages to using them in pro audio productions regardless whether your loads are power factor corrected or not.  I can think of several good reasons to operating the typical production package on a single large circuit derived from a step-down transformer rather than on a 240V splitter box consisting of 240V and 120V receptacles.  First, since there are some loads that can’t operate at 240V, balancing your 120V loads over the two legs of a portable generator is a concern. If you power your amps at 120V,  you don’t have to worry about balancing any of your loads  because the transformer does it automatically.  No matter what branch circuit you plug a 120V load into it is split evenly over the primary of the transformer so that the generator only sees a perfectly balanced load.  Second, the taps on the transformer can be used to compensate for line-loss on a long cable run and voltage drop on the generator under load, which small portable generators are very prone to.   Third, the ground/neutral bond on the secondary side of a transformer, and a ground rod, will ensure that downstream GFCI devices will operate reliably which they don’t do on the floating neutral systems of the Honda EU generators (see my IATSE Local 481 workshop on ground fault protection for more details. The workshop is available for free online at http://www.screenlightandgrip.com/html/481_GFCI_Workshop.html.) Finally, I would not be concerned about a small portable transformer raising the eyebrows of an Inspector – they are quite familiar with them from construction sites.

Guy Holt, Gaffer
ScreenLight & Grip
www.screenlightandgrip.com
Logged

TJ (Tom) Cornish

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4317
  • St. Paul, MN
Re: Generator question
« Reply #54 on: September 22, 2015, 12:07:56 PM »

Just trying to be helpful by correcting a, good intentioned I am sure, incorrect statement.  Though you may not have meant it this way, when you reference the larger 120V circuits that can be obtained by paralleling both EU2000s and EU3000s, you are no longer just talking about paralleling EU3000s , but paralleling small generators in general.  In that context your statement that “this is your only choice with small generators” is false since it is now possible to parallel EU6500s and EU7000s.
My statement wasn't incorrect; you're redefining "small generators" to be something other than what my reply - and the preceding couple of pages of posts were about - the EU3000.  This thread started in the Lab Lounge, where an EU6500 is arguably a "large generator" - especially as the thread progressed.
Since readers look to this forum for the final word on production technique, I felt it would be a disservice to the readers of this forum to not inform them of new options.  And since the OP was in fact operating lights on the generator, as do many users of small generators in this forum, I think it is relevant to point out the different ratings for peak load verses continuous load for these generators.  Again, it would be a disservice to the OP and other readers to lead them to believe the EU6500/7000 provides 30Amps per leg on the 240V receptacle straight out of the box when in fact it does not.

While operating gear at 240V will minimize neutral harmonics issues, it does not eliminate the voltage waveform distortion described in my previous post.  Better still would be to use only power factor corrected equipment that does not draw harmonic currents in the first place. Not only will equipment operate more reliably on the cleaner power, but you will be able to operate appreciably more equipment on a small generator because power factor corrected equipment is more efficient and you do not have to oversize the generator, i.e. reduce the load, in order to mitigate the adverse effects that harmonic currents can have on small generators.

Since you have now begun to debate the merits of using transformers with small portable generators, I don’t think I can be faulted for responding with what I see to be the advantages to using them in pro audio productions regardless whether your loads are power factor corrected or not.  I can think of several good reasons to operating the typical production package on a single large circuit derived from a step-down transformer rather than on a 240V splitter box consisting of 240V and 120V receptacles.  First, since there are some loads that can’t operate at 240V, balancing your 120V loads over the two legs of a portable generator is a concern. If you power your amps at 120V,  you don’t have to worry about balancing any of your loads  because the transformer does it automatically.  No matter what branch circuit you plug a 120V load into it is split evenly over the primary of the transformer so that the generator only sees a perfectly balanced load.  Second, the taps on the transformer can be used to compensate for line-loss on a long cable run and voltage drop on the generator under load, which small portable generators are very prone to.   Third, the ground/neutral bond on the secondary side of a transformer, and a ground rod, will ensure that downstream GFCI devices will operate reliably which they don’t do on the floating neutral systems of the Honda EU generators (see my IATSE Local 481 workshop on ground fault protection for more details. The workshop is available for free online at http://www.screenlightandgrip.com/html/481_GFCI_Workshop.html.) Finally, I would not be concerned about a small portable transformer raising the eyebrows of an Inspector – they are quite familiar with them from construction sites.

Guy Holt, Gaffer
ScreenLight & Grip
www.screenlightandgrip.com
We will have to agree to disagree on the relative merits of a big transformer and inspector's reactions vs. other distribution methods.  I stand by my assertion that a film set is significantly different from a lounge-level sound gig with a few LED par cans. 

If you really want to be helpful, how about condensing or dividing your epic-length white paper into something readable with relevant information for our industry geared for a non-EE reader?  The typical reader of this forum section would get about 3 paragraphs in before glossing over and missing your message.
Logged

Guy Holt

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: Generator question
« Reply #55 on: September 22, 2015, 01:18:18 PM »

My understanding is that the ability to dissipate energy is more or less the definition of ground… reason a ground connection is often called a "drain"… Without that tie to earth, something that is either tied loosely to earth or has a greater ability to dissipate energy like a big metal stage sitting on dirt (not a serious connection but a better drain nonetheless) can develop a potential between it and something with no such reference or drain. … If I've got this all wet, I'm sure we could all benefit from a basic understanding.

I may be mistaken, but this sounds vaguely like the erroneous “Sump Theory of Ground.” According to this theory "electricity wants to go to ground" because the earth is some kind of giant reservoir of electro-magnetic charge from which all electricity comes and to which it must ultimately return and dissipate. This is a commonly held fallacy and can even be found in electrical safety training videos and books published about electrical wiring.  As is evident by the fact that ground faults pose no threat in single circuit floating neutral generators demonstrates clearly the fallacy of this theory.


That there is no ground leak in this case clearly demonstrates that electricity wants to return to its source and nowhere else – especially not a supposed giant sump that is planet earth.  Electricity is attracted only to the singular magnetic field, in the core of a transformer or the rotors of a generator, from which it was created. The two low impedance conductors (the Neutral & EGC) that are designed to carry it safely are the preferred rout it takes. Whenever current goes to earth ground, or any other ground loop, it is only because it offers an alternate means to return to its' source.  In fact, according to the NEC, earth ground is not an acceptable path for fault current. I hope this has been helpful.

Guy Holt,
ScreenLight & Grip,
www.screenlightandgrip.com
Logged

Stephen Swaffer

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2671
Re: Generator question
« Reply #56 on: September 22, 2015, 09:06:45 PM »





Since you have now begun to debate the merits of using transformers with small portable generators, I don’t think I can be faulted for responding with what I see to be the advantages to using them in pro audio productions regardless whether your loads are power factor corrected or not.  I can think of several good reasons to operating the typical production package on a single large circuit derived from a step-down transformer rather than on a 240V splitter box consisting of 240V and 120V receptacles.  First, since there are some loads that can’t operate at 240V, balancing your 120V loads over the two legs of a portable generator is a concern. If you power your amps at 120V,  you don’t have to worry about balancing any of your loads  because the transformer does it automatically.  No matter what branch circuit you plug a 120V load into it is split evenly over the primary of the transformer so that the generator only sees a perfectly balanced load.  Second, the taps on the transformer can be used to compensate for line-loss on a long cable run and voltage drop on the generator under load, which small portable generators are very prone to.   Third, the ground/neutral bond on the secondary side of a transformer, and a ground rod, will ensure that downstream GFCI devices will operate reliably which they don’t do on the floating neutral systems of the Honda EU generators (see my IATSE Local 481 workshop on ground fault protection for more details. The workshop is available for free online at http://www.screenlightandgrip.com/html/481_GFCI_Workshop.html.) Finally, I would not be concerned about a small portable transformer raising the eyebrows of an Inspector – they are quite familiar with them from construction sites.


Running all of your loads on a single 120 V circuit doubles your voltage drop compared to running the same load on a 240 volt circuit.  Of course, a 120/240 volt circuit requires an extra wire.  So your pro's/con's would be to compare cost of 3 wire vs 4 wire vs cost of transformer.  Yes you can add a transformer at the end of the run-but that adds complexity to distribution plus potential issues with getting a ground rod vs with a genny typically parked outside away from production.  All trade-offs to consider.

If the generator has voltage drop under load, transformer taps would work well for a steady load-under a dynamic load such as audio, the voltage would rise, perhaps to unacceptable levels when the generator was lightly loaded-making transformer taps a less than ideal solution.  The longer(higher impedance) your run, the greater your variation as the load varies.

As for the floating neutral-it is my understanding that can be fixed with an appropriate bonding jumper.  I simple low cost solution.

I am not trying to gang up on you-but I agree that presenting your solution as a "one size fits all" magic bullet is unrealistic.  It certainly has some positives.  Whether or not the cost vs benefit makes sense, I am not sure of yet.
Logged
Steve Swaffer

Jamin Lynch

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1999
  • Corpus Christi, TX.
Re: Generator question
« Reply #57 on: September 23, 2015, 09:45:06 AM »

I'll bet by now the OP and most of the Lab Lounge folks are scratching their heads and are totally confused.

Let's say I have a small outdoor event for 300-500 max. I have 2 PRX subs and 1 PRX top per side, 4 PRX monitors and 8 LED light fixtures. I'll also need stage power for the band and for FOH. The stage is a small portable stage provided by the event people.

I have a brand new Honda EU6500. What do I need to do to make sure everyone is safe and I won't have any other power issues? Can I just plug and play?
Logged

TJ (Tom) Cornish

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4317
  • St. Paul, MN
Re: Generator question
« Reply #58 on: September 23, 2015, 09:58:25 AM »

I'll bet by now the OP and most of the Lab Lounge folks are scratching their heads and are totally confused.

Let's say I have a small outdoor event for 300-500 max. I have 2 PRX subs and 1 PRX top per side, 4 PRX monitors and 8 LED light fixtures. I'll also need stage power for the band and for FOH. The stage is a small portable stage provided by the event people.

I have a brand new Honda EU6500. What do I need to do to make sure everyone is safe and I won't have any other power issues? Can I just plug and play?
Almost: 

- Buy a male L5-30 plug, jumper the ground and neutral conductors together using a very short piece of #10 wire inside the plug, insert into the L5-30 receptacle on the generator.  This bonds the ground and neutral, which ensures GFCI devices and circuit breakers will work as intended.

- Get a 2' piece of grounding rod, a clamp, and a short piece of green stranded #10 wire.  Pound ground rod in ground (depending on the area, you may need to have the utility locator out to make sure you're not going to hit anything with your ground rod), or attach #10 wire to existing unpainted metal - bike rack, water hydrant, etc.  Attach the other end to the ground terminal on the generator.  If the stage is metal, you should really find a way to bond the stage to your generator ground, too.

- Set generator to "120V Only" mode.

- Get two inline GFCI devices like these: http://www.amazon.com/TRC-26020008-6-Shockshield-Protected-3-Outlets/dp/B000HHQIK2 and plug them into the two NEMA 5-20 receptacles on the generator.

- Divide the load between the two circuits.  I would probably put the mains and subs on one circuit and the monitors, lights, and stage power on the other.


For a somewhat larger system you might need to be a little more careful and creative, but for your example system, the above is more than adequate, doesn't require modifying the generator, and provides the best balance of safety vs. hassle.  No 200lb transformer is required.
« Last Edit: September 23, 2015, 10:02:00 AM by TJ (Tom) Cornish »
Logged

Jamin Lynch

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1999
  • Corpus Christi, TX.
Re: Generator question
« Reply #59 on: September 23, 2015, 12:52:48 PM »

Almost: 

- Buy a male L5-30 plug, jumper the ground and neutral conductors together using a very short piece of #10 wire inside the plug, insert into the L5-30 receptacle on the generator.  This bonds the ground and neutral, which ensures GFCI devices and circuit breakers will work as intended.

- Get a 2' piece of grounding rod, a clamp, and a short piece of green stranded #10 wire.  Pound ground rod in ground (depending on the area, you may need to have the utility locator out to make sure you're not going to hit anything with your ground rod), or attach #10 wire to existing unpainted metal - bike rack, water hydrant, etc.  Attach the other end to the ground terminal on the generator.  If the stage is metal, you should really find a way to bond the stage to your generator ground, too.

- Set generator to "120V Only" mode.

- Get two inline GFCI devices like these: http://www.amazon.com/TRC-26020008-6-Shockshield-Protected-3-Outlets/dp/B000HHQIK2 and plug them into the two NEMA 5-20 receptacles on the generator.

- Divide the load between the two circuits.  I would probably put the mains and subs on one circuit and the monitors, lights, and stage power on the other.


For a somewhat larger system you might need to be a little more careful and creative, but for your example system, the above is more than adequate, doesn't require modifying the generator, and provides the best balance of safety vs. hassle.  No 200lb transformer is required.

Not doubting what you are saying at all.

I've never seen anybody do that before in a similar situation.
Logged

ProSoundWeb Community

Re: Generator question
« Reply #59 on: September 23, 2015, 12:52:48 PM »


Pages: 1 ... 4 5 [6] 7 8 ... 10   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.059 seconds with 21 queries.