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Author Topic: Pulling power for ONE PA, from two different sources?  (Read 19792 times)

Steve M Smith

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Re: Pulling power for ONE PA, from two different sources?
« Reply #30 on: June 22, 2014, 01:36:39 pm »

Just to be clear, I also think the generator is the way forward.  I'm just thinking through the possibilities.

I suppose the most impractical but feasible way is to have the grounds bonded together at the houses (which they probably are already) and just run one of them to the equipment.

Again, not suggesting it is done this way, just thinking theoretically.


Steve.
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Ray Aberle

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Re: Pulling power for ONE PA, from two different sources?
« Reply #31 on: June 22, 2014, 01:56:11 pm »

And if one of the houses was *my* house, I'd just trench a conduit out to that back side and put a small post there with a range plug and a couple of GFCI 20A outlets. Cos that would be useful in the future for a multitude of things, not just the annual fireworks show.

(Or I'd drag out one of the 5 generators we have around the house. Haha.)
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Kelcema Audio
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g'bye, Dick Rees

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Re: Pulling power for ONE PA, from two different sources?
« Reply #32 on: June 22, 2014, 02:12:08 pm »

Just to be clear, I also think the generator is the way forward.  I'm just thinking through the possibilities.

I suppose the most impractical but feasible way is to have the grounds bonded together at the houses (which they probably are already) and just run one of them to the equipment.

Again, not suggesting it is done this way, just thinking theoretically.


Steve.

It matters not if it CAN be done.  The fact is it should NEVER be done short of a civic emergency.
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Mike Sokol

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Re: Pulling power for ONE PA, from two different sources?
« Reply #33 on: June 22, 2014, 03:14:18 pm »

It matters not if it CAN be done.  The fact is it should NEVER be done short of a civic emergency.

Or zombie apocalypse...  ;D
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Stephen Swaffer

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Re: Pulling power for ONE PA, from two different sources?
« Reply #34 on: June 22, 2014, 04:01:32 pm »

I would go for either the genny or a dedicated circuit from one home.

That said, a couple of thoughts, I think too often we over think and ascribe almost vodoo powers to electrons.  On the POCO side, at the transformer the primary neutral and secondary neutral are bonded together to a grounding electrode of some sort-so if you draw the circuit out, the neutrals from the 2 homes are already connected together.  The potential difference will be the voltage drops determined by the neutral currents to the 2 homes and whatever neutral exists between transformers.  Likely to be several or even 10 s of volts-but not much more UNLESS there is a problem and ta should be creating an issue in one of the homes already.

Also, if this neighborhood has metallic water lines, likely both homes are grounded to the incoming water line (actually required to be by code) so their grounds are already connected together.  Of course, other posts have mentioned "objectionable" current flowing on plumbing lines-and tis could be the case as well-also another problem that needs to be fixed.

That said, I don't want to be the nice guy donating my services that discovers a problem by a meltdown!

I am actually working on a project right now where a customer wants to use an installed backup genny to provide emergency power for small crucial loads in 2 different buildings supplied by services on separate transformers.  This obviously requires me to connect the neutrals from each service.  No objections raised by the electrical inspector, but I will update this after I talk to the POCO this week.
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Steve Swaffer

Jonathan Johnson

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Re: Pulling power for ONE PA, from two different sources?
« Reply #35 on: June 22, 2014, 06:26:59 pm »

That said, a couple of thoughts, I think too often we over think and ascribe almost vodoo powers to electrons.  On the POCO side, at the transformer the primary neutral and secondary neutral are bonded together to a grounding electrode of some sort-so if you draw the circuit out, the neutrals from the 2 homes are already connected together.  The potential difference will be the voltage drops determined by the neutral currents to the 2 homes and whatever neutral exists between transformers.  Likely to be several or even 10 s of volts-but not much more UNLESS there is a problem and ta should be creating an issue in one of the homes already.

I agree with that; it's true in most cases in the United States. However, if by some fluke of providence the houses were provided power from two different substations, this may not be the case as the shared bonding of neutrals and ground only exists on the secondary side of the substation. There is no neutral wire with the primary lines between substations. I have also seen some feeder distribution schemes where there is no common neutral with the feeder lines; the neutral is derived from the secondary side of a three phase transformer bank or even from earth ground.
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Cailen Waddell

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Re: Pulling power for ONE PA, from two different sources?
« Reply #36 on: June 22, 2014, 08:35:23 pm »

I'll also say that in my neighborhood, we have underground power, but it comes in from two sides of the neighborhood. My house is the last one on the 13kv feed from the east, my neighbor the last from the west.  Houses share the split phase step down transformers in pairs.  The neighborhood was built in 2 phases. 

Anyway - it's not out of the realm of possibility. 


Sent from my iPhone using Tapatalk
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jason misterka

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Re: Pulling power for ONE PA, from two different sources?
« Reply #37 on: June 22, 2014, 09:55:42 pm »

I am an AV professional, but in my travels I have never had a problem like this because I am always grabbing power from one structure. I am looking for input before I even think about hooking up.

I am doing an outdoor fireworks show in a neighborhood in about a week. I have been allowed to grab power from several houses on site.

Problem is:
I have one house, that will only let me have access to ONE 15 amp outlet / circuit. This is no where big enough.
I have another house about 100' away that will also give me ONE 15 amp outlet / circuit.

Current draw is going to force to to consider plugging two larger amps into house ONE, and plug the other two smaller ones, and my DSP gear into house TWO.

I know that I will have at least some ground differential between the two homes... will this cause me any problems other than "maybe some noise"?

Keep in mind all the amps are sharing earth in ONE rack, so the two houses will in theory have shared potential on ground.

Any thoughts for the newbie?

Thank you


Has anyone every though about offering a bit of money to the owner of the one house so you don't need to rent a generator?  Seems silly to me. Give the guy $50 and get a second circuit. Less money, less hassle, and more safe then a generator, that's for sure...

Jason
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Re: Pulling power for ONE PA, from two different sources?
« Reply #38 on: June 22, 2014, 10:02:47 pm »


Has anyone every though about offering a bit of money to the owner of the one house so you don't need to rent a generator?  Seems silly to me. Give the guy $50 and get a second circuit. Less money, less hassle, and more safe then a generator, that's for sure...

Jason

Again, if anything should go wrong you're on the hook for damages, long cable runs lose voltage and present tripping hazards and as mentioned before, tripping a breaker means having to go into the house to reset.

Generator is a better bet all around.
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Ray Aberle

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Re: Pulling power for ONE PA, from two different sources?
« Reply #39 on: June 22, 2014, 10:11:28 pm »

Give the guy $50

And the OP says he found an EU3000is for $100.00 for the day-- twice the money you suggest, and *surprise surprise* a much better solution.

I think SOMEONE in the neighborhood should already have a small generator, though. And if not, they should buy one. :-p

Ray
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Kelcema Audio
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Re: Pulling power for ONE PA, from two different sources?
« Reply #39 on: June 22, 2014, 10:11:28 pm »


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