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Old 12-07-2012, 11:44 PM   #1
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Default 3 wire 240V Spa Panel to 4 wire out (AGAIN)

Okay, so I know this has been beaten to death but I am still unsure. Has anybody used P-J's diagram to run a 3 wire 240V dryer setup and successfully ran a 4 wire setup with 120v and 240 applications with a GFCI spa panel? looking to use the spa panel to run at most 2 pumps and 1 5500Kw element at a time. Also, the main panel is about 10 feet from where I plan to brew, should I run a dedicated ground from the panel separately and into the spa panel? Or will I be fine splitting the neutral in the spa panel as depicted by P-J?

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Old 12-08-2012, 02:02 AM   #2
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Duck and cover, lol. First, these are my impressions given prior discussions and what I have been able to find. Second, I am not an electrician, but I am a reasonable logician. Third, my intent is to dispassionately look at the issues, not to attack anyone, and not to impugn anyone's character.

If you can run a dedicated ground from the main panel to the spa panel, or rewire with 4 wires from the main panel, then do it. That is a clean solution.

Now, if you are going to wire the spa panel with H-H-N in, bond the N and G to the spa panel chassis, run H-H-N-G out to the control panel, and wire both 120V and 240V in your control panel:

Will it work? Yes.

Does it conform to code? If you were to hardwire it as part of your house wiring, it does not conform to code, as the spa panel is not a grandfathered device that allows bonding N and G (more precisely, allows connecting the frame of the device to neutral, and using the neutral as the grounding conductor for that device). If you were to make the spa panel a "pluggable" device, you have not changed your house wiring, so you have not violated code with your house wiring. However, you have built a device (the spa panel) that does not qualify as grandfathered, and certainly violates the spirit of the code if not the letter.

Is it dangerous? Risk is relative. In a worst case scenario, say your control panel neutral comes loose and gets good contact with your control panel ground, and the GFCI in the spa panel fails, your spa panel chassis could be conducting 120V. If you were touching it and you were the shortest path to ground, then you would carry the current. This may be unlikely, but it is basically a variation of the scenario that led the NEC to change the code and require a dedicated ground wire. Incidentally, if you have a 3-wire dryer or range, the same scenario is possible if the neutral is compromised and you become the ground path. One could argue that these pose even more risk, because there is no GFCI protection to detect that the neutral is compromised and kill the power.

Understand the risks, and make your own decision. I would say you should really try to go with a dedicated ground. If you choose to use the 3-in, 4-out, spa panel solution, recognize that you are taking some risks that you can mitigate some by always testing that your GFCI is functioning, by putting the spa panel somewhere where neither you nor anyone else is likely to touch it while energized, and by neither selling, lending, nor giving the system to anyone else who does not understand the risks.

I sincerely hope that I succeeded in my attempt to discuss this issue in a balanced manner.

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Old 12-08-2012, 02:23 AM   #3
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...
I sincerely hope that I succeeded in my attempt to discuss this issue in a balanced manner.
Well said. And - Thank you.

BTW: Because of all the hype and attacks on my diagrams, I've not drawn any additional diagrams since their whole BS debacle started. Why bother. They all expect a home owner to fully understand the NEC code whenever they plug something into an outlet. They also don't seem to understand how a clothes dryer or range is (was) wired. Not my problem anymore. If I don't continue to provide advice and diagrams, I'm sure they all will simmer down & be happy.

Not me, but that's the way it goes.

Shrug.
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Old 12-08-2012, 02:49 AM   #4
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Now, if you are going to wire the spa panel with H-H-N in, bond the N and G to the spa panel chassis, run H-H-N-G out to the control panel, and wire both 120V and 240V in your control panel:

Will it work? Yes.
I agree, it'll work as far as the electrical circuit goes and I agree with 99% of the rest too.

What I'll suggest as different though is that you're not really running HHNG out anyway, it's still just HHN. There's no point to use a 4 wire receptacle & plug on the output if you're going to go this way.
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Old 12-08-2012, 03:32 AM   #5
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I agree, it'll work as far as the electrical circuit goes and I agree with 99% of the rest too.

What I'll suggest as different though is that you're not really running HHNG out anyway, it's still just HHN. There's no point to use a 4 wire receptacle & plug on the output if you're going to go this way.
EXCEPT if the table, rack or equipment has a path to 'earth'...!

Think about it.!!!


Edit: Nevermind. Another violent argument is about to develop.
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Old 12-08-2012, 08:14 AM   #6
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I'm tired of the 3/4 wire debate. Here is the deal. Will it work? Yes. Is it up the the current electrical code? No. Will you hypothetically burn your house down? never. Its about the same as touching your clothes dryer and washer machine both at the same time in a old house, while barefoot on a wet floor. Yea you may get a lil buzz, but ehh you should of been wearing shoes anyways. Seriously though. If you're going to go all out and build a electric brewery. Basically spend hundreds possibly thousands of dollars, why would you skimp on the power source, You likley wouldnt skimp on using inferior parts elsewhere. Your power feed should be valued just as important as any other part of your brewery. I wish we could get past this well documented issue. It would be nice to see some new ideas in the electric forum rather than beating old mute issues into the ground.

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Old 12-08-2012, 12:03 PM   #7
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EXCEPT if the table, rack or equipment has a path to 'earth'...!

Think about it.!!!
I have thought about it that's entirely the point.

If you're changing the context to a true equipment ground back to the main panel I agree 110%.

But, in the context of a three wire input, in the context of this arrangement, there is no point to adding the 4th wire on the output side. Might just as well connect all that stuff directly to neutral because that's all you're doing anyway.

There is no disrespect intended and on chance new readers see this I don't advocate the approach, just stating what is.
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Old 12-08-2012, 02:55 PM   #8
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Okay, just reaffirming what I already know. Thanks for everyone's input. Consider this thread closed.

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Old 12-08-2012, 04:10 PM   #9
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I have thought about it that's entirely the point.

If you're changing the context to a true equipment ground back to the main panel I agree 110%.

But, in the context of a three wire input, in the context of this arrangement, there is no point to adding the 4th wire on the output side. Might just as well connect all that stuff directly to neutral because that's all you're doing anyway.

There is no disrespect intended and on chance new readers see this I don't advocate the approach, just stating what is.
One reason to have everything wired as four wire from the beginning is so when the outlet situation changes from HHN to HHNG, it's a super easy switch of the Spa panel wiring and cord to have everything set up with the dedicated ground. This is exactly what I did.

I do agree that even though the risks are not great, it's better to look into your options to upgrade your outlet first as it may not end up being very costly or problematic.

I'm also tired of this debate but it probably answers a lot of people's questions too, so it's not such a bad thing.
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Old 12-09-2012, 03:05 PM   #10
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I'm also tired of this debate but it probably answers a lot of people's questions too, so it's not such a bad thing.
Agreed. A sticky might be a good idea, if we can generally agree on a clear and objective description.
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