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Joined: Jul 2004
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I understand the earth can be a ground path and the whole pool, spa, screen cage, deck, pumps and cover may be somewhere above zero volts compared to some theoretical ground but it will all be the same amount above zero volts if everything is bonded together. 680.26(A) says it all 680.26 Equipotential Bonding.
(A) Performance. The equipotential bonding required by this section shall be installed to reduce voltage gradients in the pool area. "Ground" is really pretty meaningless anyway. I have seen 35v between the ground electrode systems of 2 buildings (on my Dranitz). We ended up bonding them together to stop stuff from blowing up when we strung data cables between them.
Greg Fretwell
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Joined: Oct 2000
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ok, so what we have is a code consession Greg, due to 680.26 trumping 250.6 (note HB commentary, and 250.6D's commentary)
that said, this immovable NEC mobius strip logic does not mitigate the underlying irresistable electrical theory via the introduction of componets becoming inversley proportial to their intended goals
~S~
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Joined: Feb 2002
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Greg, I got it! I just thought of the perfect solution! I will router a line all around the hot tub on the wooden deck, stick the #8 bare in there and putty it all up, so that no one trips over the wire. Neat right? And if it comes to a composite deck, I can use a hot knife to melt a track in the deck around the tub. You know I am just kidding right? 
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Joined: Jul 2004
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There is no conflict between 250.6 and 680.26. You are still supposed to separate the neutral from the EGC anywhere on the load side of the service disconnect so you should not have any circuit current in the EGC. Any current you see in the EGC is going to be between separate services and technically it will be on the line side of the EGCs. We tend to deny that exists and it is not in the scope of the NEC. I had a big dust up with an FPL guy one day when he said there was no current flowing through the earth from their wye distribution services. He simply did not understand the idea that current takes ALL paths. I showed him there was an amp or two flowing in the ground wires running down his poles and he still denied that was current flowing through the earth. This one had almost 3 amps ![[Linked Image from gfretwell.com]](http://gfretwell.com/electrical/First%20xfmr.jpg)
Greg Fretwell
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There is no conflict between 250.6 and 680.26.
You are still supposed to separate the neutral from the EGC anywhere on the load side of the service disconnect so you should not have any circuit current in the EGC.
Any current you see in the EGC is going to be between separate services and technically it will be on the line side of the EGCs. We tend to deny that exists and it is not in the scope of the NEC.
I had a big dust up with an FPL guy one day when he said there was no current flowing through the earth from their wye distribution services. He simply did not understand the idea that current takes ALL paths. I showed him there was an amp or two flowing in the ground wires running down his poles and he still denied that was current flowing through the earth.
This one had almost 3 amps
or put otherwise, one may try and do the other's job , in that you 'EGC' a large piece of anything to earth , especially in the right path, and it may well become one of those 'all paths' you speak of
~S~
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Joined: Jul 2004
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I agree the GEC does become part of the distribution system but as long as everything on the load side of the MBJ is isolated from the neutral there should not be anything but fault current flowing and that should quickly operate the over current device. Outside it will certainly trip the GFCI
Greg Fretwell
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yes Greg, but let me pose a scenario.
Said GFI trips while the spas aren't even in operation
Naturally one would wonder about this.
Consider all ECG's and GEC's could be (and often are around here) married to the panel MBJ noodle bar
I suspect this is why the nec put (the old) 250.32B out to pasture, but the same phenomenon that inspired them to do so can still exist bettween dwellings, and even within dwellings.
consider, for example the old 3 wire dryers and stoves which bond noodles to their shells
~S~
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Joined: Jul 2004
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I would like to get involved in the investigation of a GFCI tripping with no load present.
Greg Fretwell
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Joined: Jul 2004
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I would like to get involved in the investigation of a GFCI tripping with no load present.
It would scream, "regrounded neutral" to me.
The code pretty much dictates that the grounded, grounding and GEC all get connected together in the service disconnect can. The only time this is not true is when the GEC lands somewhere else on the line side grounded conductor.
It still does not change the fact that the grounded and grounding conductors should never meet again.
Greg Fretwell
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Joined: Oct 2000
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I would like to get involved in the investigation of a GFCI tripping with no load present.
It would scream, "regrounded neutral" to me.
The code pretty much dictates that the grounded, grounding and GEC all get connected together in the service disconnect can. The only time this is not true is when the GEC lands somewhere else on the line side grounded conductor.
It still does not change the fact that the grounded and grounding conductors should never meet again.
i'd only state that we've a lotta old, and mostly uninspected wiring in Vermont.
for instance, we're lousy with 'subpanels' without a floating noodle
they all seem to fall under that 'existing' black hole
which is often the bane of my existence, being i end up the 'bad news guy'
~S~
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