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I don't know who else this might affect, but just so's you know.

I busted a sub-panel recently in a new detached garage because the grounds and neutrals weren't segregated on separate terminal bars. Turns out it was okay, though, because separate ground rods had been installed for the garage sub-panel behind the building. This came from the electrician, and I later verified it with our electrical inspection department.

Thing is, Kentucky hasn't adopted the 2008 NEC, which prohibits the foregoing. But the 2004 NEC--according the inspection folks--allows the set-up.

So it's wrong, but it's right, but it's wrong . . . or something like that.

I suppose the moral is that if your state is still using the 2004 NEC look for a grounding rod before deciding whether the sub-panel is wired properly or not.

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In that situation, under the previous codes, you also have to ask yourself if there are any "continuous metallic pathways" between the two buildings (TV or phone cables, metal fences, rebar, metal plumbing pipes, you name it). If so, it must be wired as a sub panel. It has to have its own GEC either way.

Brian G.

The Rules Are Whatever the Rulemakers Say They Are (Now) [:-boggled

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Originally posted by Richard Moore

But the 2004 NEC--according the inspection folks--allows the set-up.

Never trust a man with a 3-dollar bill or a copy of the 2004 NEC!

Well, Well, Well, I missed getting my 2004 NEC. I have the 2002, 2005, and need to get me a copy of the 2008.[:-angel]

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Originally posted by Bain

I don't know who else this might affect, but just so's you know.

I busted a sub-panel recently in a new detached garage because the grounds and neutrals weren't segregated on separate terminal bars. Turns out it was okay, though, because separate ground rods had been installed for the garage sub-panel behind the building. This came from the electrician, and I later verified it with our electrical inspection department.

*Every* seperate building that has electricity (and more than one circuit) is supposed to have its own grounding electrode system. That's got nothing to do with the requirements for isolating the neutral. The requirement for isolating the neutral kicks in when there's a metal path between the seperate building and the building where the feeder originates.

Thing is, Kentucky hasn't adopted the 2008 NEC, which prohibits the foregoing. But the 2004 NEC--according the inspection folks--allows the set-up.

There was no 2004 NEC, it was either the 2002 or the 2005.

So it's wrong, but it's right, but it's wrong . . . or something like that.

Depends on the presence of a metal pathway. If there's no metal path and there aren't four wires in the feeder, there's no need for the neutral to be isolated under the 2004 NEC.

I suppose the moral is that if your state is still using the 2004 NEC look for a grounding rod before deciding whether the sub-panel is wired properly or not.

No. I suspect that, either KY has made up its own rule over and above the NEC or the people you spoke with were misinformed.

As a general rule, when you talk with folks about this stuff, ask for the chapter & verse, then go look it up to verify. There's lots and lots of misinformation out there.

I'd start with 250.32(A) & (B). The requirements are very clear.

- Jim in Oregon

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Originally posted by Bain

I don't understand what you're saying, Brian.

Are you agreeing with what I was told, or not?

What Jim said. Just having a GEC doesn't mean it can be wired with only three conductors. It has to have that whether the neutrals and grounds get seperated or not.

By the way, you can have a seperate GEC on a sub panel in the same building, as long as it's bonded to the grounding system of the service equipment, but it isn't required.

Brian G.

The GEC

of the SE

Required By the NEC

Can be a Catastrophe

As You Can Clearly See

(ode to Jesse Jackson) [;)]

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I said "2004" because that's what the electrician quoted. I suppose he meant "2005."

There was no metal pathway, that I recall. But the garage was wired for 240 volts, so the feeder cable was a four-wire. If only the hots and neutral were used from the cable, and not the ground, would that mean it's okay for the sub-panel grounds and neutrals to be comingled? My take on the conversation with the electrician was that segregation wasn't necessary because the detached garage's panel wasn't relying on the main panel for grounding.

I'll check out the reference you cited, Jim.

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Originally posted by Bain

I said "2004" because that's what the electrician quoted. I suppose he meant "2005."

There was no metal pathway, that I recall. But the garage was wired for 240 volts, so the feeder cable was a four-wire. If only the hots and neutral were used from the cable, and not the ground, would that mean it's okay for the sub-panel grounds and neutrals to be comingled? My take on the conversation with the electrician was that segregation wasn't necessary because the detached garage's panel wasn't relying on the main panel for grounding.

I'll check out the reference you cited, Jim.

Under the 2004 NEC if there's a four wire feeder the outbuilding panel must have it's neutral and grounding wires separated. In that case, the metal pathway doesn't matter. The presence of an equipment grounding conductor is the determining factor.

There is no question that the NEC requires the panel you saw to have its neutrals isolated from its grounding wires.

My reference is 250.32(B)(2). If someone disagrees, ask him for a reference.

- Jim Katen, Oregon

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Jim,

I think the confusion lies in the dates of the NEC. You very clearly state that there is no 2004 code, only 2002 or 2005, and then twice reference the 2004 code.

In any event, it's a moot point with regards to the panel in question. The AHJ blessed it, so it likely won't get repaired.

Tom

As always, your wisdom is greatly appreciated. Even with the typos.

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Originally posted by Tom Raymond

Jim,

I think the confusion lies in the dates of the NEC. You very clearly state that there is no 2004 code, only 2002 or 2005, and then twice reference the 2004 code.

I should have put 2004 in quotation marks since I was trying to use John's term for whatever code was in effect. Sorry for the confusion. It was poor communication on my part.

However, with this particular issue, the NEC hasn't changed much since as far back as '96. If KY is on the 1999, 2002, 2005 or 2008 NEC, the setup he describes is incorrect.

In any event, it's a moot point with regards to the panel in question. The AHJ blessed it, so it likely won't get repaired.

Possibly not. But I never let that prospect affect my recommendations.

As always, your wisdom is greatly appreciated. Even with the typos.

Well, thanks. It's nice to know that I don't toil in vain. I'll try to cut down on the typos.

- Jim Katen, Oregon

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Well, for what it's worth . . . I explained to the buyer that, 1) even if it was allowed at one time, it isn't allowed now, and 2) that someone more knowledgable than me--JK--confirmed my original opinion, and 3) that correcting the sub-panel shouldn't cost more than a couple of hundred bucks at most.

The house in question is selling for seven figures and the buyer is savvy enough to realize that the electrical inspection guys are exactly what they are.

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