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Author Topic: Honda EU3000iS gennys in parallel  (Read 29184 times)

Guy Holt

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Re: Honda EU3000iS gennys in parallel
« Reply #30 on: June 19, 2015, 04:59:59 PM »

So if paralleling EU3000is gennys into a common bus...I'm using each EU3000is to feed one leg of the Cali-50 or L14-50 receptacle. We have zero 240-volt equipment, and no double-pole breakers in our distro breaker boxes. If we balance our loads manually (FOH amps on one genny, and backline plus LED lights on the other leg) nothing will care that the L1 to L2 voltage will slowly drift between 0 and 240 volts. ...What do you all think? I know this is a bit strange but I don't see any reason why it won't work and be completely safe.

I can see one possible problem with this hare brained idea.  As you know there need be only one neutral wire for the two hot wires in your distro because under normal applications the current on the neutral is the difference between the hot legs because of the phase cancellation between legs that are either 180 or 120 degrees out of phase. Either way there is minimal current to return on the neutral under normal applications and so the neutral wire can be the same size as that of the hot legs.

Now if I understand this set up, the phase angles of the two EU3000s are not locked in anyway, meaning that they could be 180 or 120 degrees, but could just as likely be 5 degrees out of phase.  In the latter case there will be virtually no phase cancellation on the neutral and the neutral will be carrying nearly twice the current of the hot legs which could spell trouble if the neutral of your distro is not oversized by a factor of two.

Guy Holt, Gaffer
ScreenLight & Grip
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Mike Sokol

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Re: Honda EU3000iS gennys in parallel
« Reply #31 on: June 19, 2015, 05:11:05 PM »

In the latter case there will be virtually no phase cancellation on the neutral and the neutral will be carrying nearly twice the current of the hot legs which could spell trouble if the neutral of your distro is not oversized by a factor of two.

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

Guy, the idea is to use existing 50-amp feeder and distro with a pair of 23.3 amp generators, so the max current the neutral could ever carry would be 46.6 amps. And that's assuming a worst case scenario with the free running clocks accidentally settling in a 0 degrees phase shift from each other.

I know this will work.... The question is would it be a code violation?
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Mike Sokol
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Stephen Swaffer

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Re: Honda EU3000iS gennys in parallel
« Reply #32 on: June 19, 2015, 08:06:33 PM »

The only code question I can think of is the requirement for shared neutrals to have a common disconnect.  As well as to be sure there is one and only one G-N bond.  People have a way of misusing good ideas-I could see a mix and match last minute fix resulting in a second bond being created-though with full size neutrals and grounds as we typically have in SO cord I am not sure I would lose much sleep over a second bond.

Also, with all the universal voltage amps out there and guys wanting to run 220/240 for various reason's make sure the distro used with this does not have any 220 receptacles.

I am not as familiar with harmonic generation as others-but the current waveform on the neutral could look odd-is there a chance of this causing any interference?

Here in Iowa the parking lot/backyard gigs are already getting into full swing-gonna be a busy summer-even without the straw poll! 
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Steve Swaffer

Mike Sokol

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Re: Honda EU3000iS gennys in parallel
« Reply #33 on: June 19, 2015, 08:27:08 PM »

The only code question I can think of is the requirement for shared neutrals to have a common disconnect.  As well as to be sure there is one and only one G-N bond.  People have a way of misusing good ideas-I could see a mix and match last minute fix resulting in a second bond being created-though with full size neutrals and grounds as we typically have in SO cord I am not sure I would lose much sleep over a second bond.

Also, with all the universal voltage amps out there and guys wanting to run 220/240 for various reason's make sure the distro used with this does not have any 220 receptacles.

I am not as familiar with harmonic generation as others-but the current waveform on the neutral could look odd-is there a chance of this causing any interference?

Here in Iowa the parking lot/backyard gigs are already getting into full swing-gonna be a busy summer-even without the straw poll!

Steve, thanks for your input. This would be for my personal distro rig only, and just for those times when I want to push beyond a single EU3000is but don't want the hassle of a full size genny.

On a side note, when I did the last presidential election on the parade route at La Fayette Park, we weren't allowed to bring in any addition fuel. So whatever we had in the genny onboard fuel tanks was all we had for the entire gig which took some 10 days to set up. So we only ran the generators an hour per day for testing since we needed them the entire day of the inauguration and didn't dare run out of diesel. All was well since big gennys have big fuel tanks.
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Mike Sokol
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Jonathan Johnson

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Re: Honda EU3000iS gennys in parallel
« Reply #34 on: June 21, 2015, 10:01:38 PM »

So if paralleling EU3000is gennys into a common bus is complicated because of the balancing issues, what about considering them as two legs of 120-volts which are not phase-locked together. Now before everyone starts yelling at me about hot male plugs (sounds like a good name for a band) notice on the diagram below I'm using each EU3000is to feed one leg of the Cali-50 or L14-50 receptacle. We have zero 240-volt equipment, and no double-pole breakers in our distro breaker boxes. If we balance our loads manually (FOH amps on one genny, and backline plus LED lights on the other leg) nothing will care that the L1 to L2 voltage will slowly drift between 0 and 240 volts.

Also note that I tied the neutrals and grounds together from the two gennys (going to happen no matter what) and added a Neutral-Ground bonding switch. Just add a ground stake and this could be used with existing Cali-50 or NEMA 14-50 distro cables.

What do you all think? I know this is a bit strange but I don't see any reason why it won't work and be completely safe. I'm pretty sure code doesn't address this sort of thing, but I don't see why they would exclude it either as long as everything was properly marked.

The flaw I see is ensuring that no one connects 240V equipment, which could energize a disconnected male plug. That would mean making sure there are no 240V circuits in your distro, and putting lockable in-use covers over these receptacles.

Good luck convincing an inspector -- or the Secret Service -- that it is safe and nobody will get hurt or killed.
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Mike Sokol

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Re: Honda EU3000iS gennys in parallel
« Reply #35 on: June 22, 2015, 07:57:49 AM »

Good luck convincing an inspector -- or the Secret Service -- that it is safe and nobody will get hurt or killed.
Interestingly, the Secret Service has never bugged me about electrical grounding or power distro for a political event. They worry about the potential for explosive devices which is why we can't bring in Jerry cans of gasoline or diesel fuel. Plus they worry about things like where I walk and what radio frequencies we're using. I'm also not allowed to say phrases such as "shoot me some audio" over the radio, so now I ask the crew to "squirt me some audio". In fact one time after we had random GFCI tripping from a genny distro during a sound-check, the White House Press Corp asked us to remove the GFCI receptacles since they were worried about losing power in the middle of a political event.

But I agree that using UL listed distribution devices should help with any inspection process. We just don't get a lot of inspectors showing up at events on the east coast.
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Mike Sokol
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Steve M Smith

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Re: Honda EU3000iS gennys in parallel
« Reply #36 on: June 22, 2015, 08:47:55 AM »

In fact one time after we had random GFCI tripping from a genny distro during a sound-check, the White House Press Corp asked us to remove the GFCI receptacles since they were worried about losing power in the middle of a political event.
The British army has something they call battleshort mode where trips are mechanically held in the on position for times when they would rather have something burn up than take out the power to other things.
I'm sure your armed forces have something similar.


Steve.
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Mike Sokol

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Re: Honda EU3000iS gennys in parallel
« Reply #37 on: June 22, 2015, 09:08:51 AM »

The British army has something they call battleshort mode where trips are mechanically held in the on position for times when they would rather have something burn up than take out the power to other things.
I'm sure your armed forces have something similar.

I guess they don't want their rocket launcher power going down at a bad moment. ;D
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Mike Sokol
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Stephen Swaffer

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Re: Honda EU3000iS gennys in parallel
« Reply #38 on: June 22, 2015, 09:57:57 AM »

To me the best way to implement this would be a female cord end that matches the distro plug, feed with 2 10-3 so cords wired to plug into the gennies.  The plugs serve as you disconnect.  As long as there are no 220 receptacles on the distro.  The hazard being that if a load is connected to a 220 plug, the potential exists to energize the male plug if it is disconnected from the genny-in the same manner that a shared neutral can be energized through a load connected to a still energized hot conductor.

The common disconnect for a shared neutral is intended for maintenance in buildings, etc.  I am hoping anyone doing work on a distro is smart enough to completely disconnect it from any power source-else they deserve any Darwin award they receive.

Have east coast inspectors gone high tech in the 21st century, accepting payments by phone rather than cash slipped through a handshake??
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Steve Swaffer

Mike Sokol

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Re: Honda EU3000iS gennys in parallel
« Reply #39 on: June 22, 2015, 10:07:59 AM »

Have east coast inspectors gone high tech in the 21st century, accepting payments by phone rather than cash slipped through a handshake??
We just put an envelope loaded with a few Jackson's in the panel being inspected. Sort of like putting out cookies and milk for Santa... 8)
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Mike Sokol
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Re: Honda EU3000iS gennys in parallel
« Reply #39 on: June 22, 2015, 10:07:59 AM »


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