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nunya
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reply to Jack_in_VA

Re: Bare ground need conduit ??

Your inspector was wrong and the electrician was right. At an outbuilding with a feeder other than a branch circuit (E.G. sub-panel) then a grounding electrode is required (doesn't have to be a ground rod, but that's typically the defacto choice). The 4-wire circuit is required too. Technically, the feeder EGC does not need to be a #6 and is sized by 250.122.
If you drill down through the code far enough 250.32 (and this one is a tough one), you'll wind up at section III and 250.66.
There GEC at that location (the outbuilding) is sized by 250.66, where the minimum size GEC is #8 copper.
If you look at 250.66 it answers all the questions. No GEC going to a ground rod shall be required to be larger than #6 copper regardless of table 250.66.
If you go back to 250.53, they say that can't just use a single ground rod unless the resistance can be proved to 25 ohms. Most inspectors aren't going to call anybody out on this.
Any additional ground rads at the location (outbuilding) must be bonded together by, you guessed it, #6. Even if the GEC is a #8, and the EGC is a #10, the bond between rods "at the location" must be #6 minimum.

The code writers could do a much better job with article 250. It's a mess and hard to decipher. Especially for "multi-hat" inspectors who may not have an electrical background.
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Jack_in_VA
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nunya it does not matter what the code says it's what the AHG says and without his sign-off the POCO will not reconnect the service.

Actually it's not a sub-panel but a 100 amp branch panel fed off the load side of the meter base in parallel with the line side of the house service panel.

People can argue the Code book all they want but it boils down to what the AHJ demands. Sure you can contest it but is it worth it? I'm just as safe so I really don't care.


John Galt
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Happy Camp
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said by Jack_in_VA:

Actually it's not a sub-panel but a 100 amp branch panel fed off the load side of the meter base in parallel with the line side of the house service panel.

That's the difference right there...


Jack_in_VA
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said by John Galt:

said by Jack_in_VA:

Actually it's not a sub-panel but a 100 amp branch panel fed off the load side of the meter base in parallel with the line side of the house service panel.

That's the difference right there...

But the inspector also made the electrician install a parallel ground rod 5 ft from the original and tie the two together with (NOT ONE) but 2 #6 bare copper conductors. Go Figure.


John Galt
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said by Jack_in_VA:

Go Figure.

Like you said, what Lola wants, Lola gets.


whizkid3
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Queens, NY
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reply to nunya
said by nunya:

Your inspector was wrong and the electrician was right. At an outbuilding with a feeder other than a branch circuit (E.G. sub-panel) then a grounding electrode is required (doesn't have to be a ground rod, but that's typically the defacto choice). ...

Nunya is on the money here. And from what one can see with even his 'simplified' explanation, is that it is a very complex subject that is best left to the pros. And often, many of them get it wrong as well.

Yeah, if the AHJ demands something and you are not a PE or licensed master electrician; you are basically going to have little other recourse but to follow their wishes. Often, even when you are a PE or master electrician - you may still want to follow their (incorrect) wishes, unless its a large monetary hit or other substantial reason to disagree.

quote:
But the inspector also made the electrician install a parallel ground rod 5 ft from the original and tie the two together with (NOT ONE) but 2 #6 bare copper conductors. Go Figure.
WTF? Obviously from a carpentry background.


Jack_in_VA
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said by whizkid3:

said by nunya:

Your inspector was wrong and the electrician was right. At an outbuilding with a feeder other than a branch circuit (E.G. sub-panel) then a grounding electrode is required (doesn't have to be a ground rod, but that's typically the defacto choice). ...

Nunya is on the money here. And from what one can see with even his 'simplified' explanation, is that it is a very complex subject that is best left to the pros. And often, many of them get it wrong as well.

Yeah, if the AHJ demands something and you are not a PE or licensed master electrician; you are basically going to have little other recourse but to follow their wishes. Often, even when you are a PE or master electrician - you may still want to follow their (incorrect) wishes, unless its a large monetary hit or other substantial reason to disagree.

quote:
But the inspector also made the electrician install a parallel ground rod 5 ft from the original and tie the two together with (NOT ONE) but 2 #6 bare copper conductors. Go Figure.
WTF? Obviously from a carpentry background.

Whiz I'm in a one-man AHJ operation county here. That may explain it. He retired and now we have a retired Fire Department Inspector (whatever that is). I haven't had any dealings with him.

laserfan

join:2005-01-14
Texas
reply to nunya
Well this has gotten complicated hasn't it. Since there are no "authorities" where I live (had to look-up AHJ and a couple other acronyms) I'm going with ground rods at all outbuilding panels, all tied together.



alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by laserfan:

Well this has gotten complicated hasn't it. Since there are no "authorities" where I live

No actually it gets quite simple: Do what the NEC says to do (AKA Nunya/Whizkid).


nunya
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reply to laserfan
Most states will adopt codes to cover areas not covered by a city or county ordinance.
Even if you live in the most remote part of Alaska, there's still a code requirement.
There may not be anyone available to enforce it, but you owe it to yourself to do it right (or have it done right).
Remember, code is the bare minimum. It's the least you can "get away with".
--
If someone refers to herself / himself as a "guru", they probably aren't.

laserfan

join:2005-01-14
Texas
reply to alkizmo
said by alkizmo:

said by laserfan:

Well this has gotten complicated hasn't it. Since there are no "authorities" where I live

No actually it gets quite simple: Do what the NEC says to do (AKA Nunya/Whizkid).

Ha, ha! Good one!

Yes, in TX everyone is supposed to go by the NEC.

said by nunya:

At an outbuilding with a feeder other than a branch circuit (E.G. sub-panel) then a grounding electrode is required (doesn't have to be a ground rod, but that's typically the defacto choice). The 4-wire circuit is required too. Technically, the feeder EGC does not need to be a #6 and is sized by 250.122.
If you drill down through the code far enough 250.32 (and this one is a tough one), you'll wind up at section III and 250.66.
There GEC at that location (the outbuilding) is sized by 250.66, where the minimum size GEC is #8 copper.
If you look at 250.66 it answers all the questions. No GEC going to a ground rod shall be required to be larger than #6 copper regardless of table 250.66.
If you go back to 250.53, they say that can't just use a single ground rod unless the resistance can be proved to 25 ohms. Most inspectors aren't going to call anybody out on this.
Any additional ground rads at the location (outbuilding) must be bonded together by, you guessed it, #6. Even if the GEC is a #8, and the EGC is a #10, the bond between rods "at the location" must be #6 minimum.

The code writers could do a much better job with article 250. It's a mess and hard to decipher. Especially for "multi-hat" inspectors who may not have an electrical background.



leibold
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reply to Jack_in_VA
said by Jack_in_VA:

But the inspector also made the electrician install a parallel ground rod 5 ft from the original and tie the two together with (NOT ONE) but 2 #6 bare copper conductors.

He wasn't German by any chance ? It does sound like the German Engineering approach of precisely determining the safety requirements and then doubling everything anyway

In case anybody is wondering, in many areas it is now required to have a minimum of two grounding electrodes (the buried water supply line is often counted as one of them) however the two ground rods Jack mentions only count as one since they are too close together (only 5ft apart).
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laserfan

join:2005-01-14
Texas
said by leibold:

In case anybody is wondering, in many areas it is now required to have a minimum of two grounding electrodes (the buried water supply line is often counted as one of them)

In the TX countryside there are no metal water pipes underground, and the "soil" itself is mostly rock, such that it's difficult even to get a ground rod driven-in. There are wires alongside every power pole fwiw, that get buried with the pole--I suppose that's SOP everywhere.

So for all the controversy here about "to add a ground or not" I'm inclined to err on the side of "ground wherever you can".


Jack_in_VA
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said by laserfan:

said by leibold:

In case anybody is wondering, in many areas it is now required to have a minimum of two grounding electrodes (the buried water supply line is often counted as one of them)

In the TX countryside there are no metal water pipes underground, and the "soil" itself is mostly rock, such that it's difficult even to get a ground rod driven-in. There are wires alongside every power pole fwiw, that get buried with the pole--I suppose that's SOP everywhere.

So for all the controversy here about "to add a ground or not" I'm inclined to err on the side of "ground wherever you can".

Even if it sets up a very dangerous "difference of potential" by improper bonding of the grounds by some people installing them that really don't have the knowledge of what they are doing? The "more ground rods the better" is not necessarily correct.

laserfan

join:2005-01-14
Texas
Yeah, but it's clear from this thread that there is no "correct" afaict.



alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by laserfan:

Yeah, but it's clear from this thread that there is no "correct" afaict.

Yes there is a "incorrect" because there IS a "correct" way to put in grounding electrodes.

If the military can ground their portable electrical equipment in the mountains, then I'm sure you can get a good ground in rocky soil in Texas.

You might not be able to get a ground rod in, but you could get several ground plates in there, or a ground grid. It just requires heavy machinery instead of a sledge hammer.

Then as Jack_in_VA said, it's also about properly bonding the electrodes together, which a weekend warrior who doesn't understand the difference between grounding and bonding might horribly screw up.

I'm not an electrician, but I'm pretty handy, yet when it comes to grounding, I still err on the side of caution and get validation from the pros.

I mean, just look at this thing (That's just 1 out of 12 pages).
»ecmweb.com/bonding-amp-grounding···art-1-12
It's a LOT of stuff to understand.

laserfan

join:2005-01-14
Texas

1 edit
said by alkizmo:

I'm not an electrician, but I'm pretty handy, yet when it comes to grounding, I still err on the side of caution and get validation from the pros.

I mean, just look at this thing (That's just 1 out of 12 pages).
»ecmweb.com/bonding-amp-grounding···art-1-12
It's a LOT of stuff to understand.

And I only "worked with" electricians and electrickery for some years, thus knowing just enough to be dangerous.



What a great link, thanks; I have bookmarked it and will study thoroughly at another time when my brain is at 100%. Early Xmas morning here and I'm a little bleary-eyed.

Happy holidays everyone!

laserfan

join:2005-01-14
Texas
reply to alkizmo
said by alkizmo:

I mean, just look at this thing (That's just 1 out of 12 pages).
»ecmweb.com/bonding-amp-grounding···art-1-12
It's a LOT of stuff to understand.

You ain't just whistlin' Dixie brother--I've only Skimmed it (not yet Studied it) and so far all I've gotten out of it is that you can't count on Earth Ground for a "return path", and (I think) also that while it Used To Be that a remote building didn't need a ground rod, now it is recommended to have a ground rod In Addition to a ground Conductor/Wire back to the service panel.

Gonna read it again (and again) but it does make my brain hurt...