NEC 250.32B1 Isolate neutral from EGC

Electrician says nothing wrong with sub panel. Wants to know from what code I am calling this out. Do I have the correct code? He said it is alright the way it is neutral and grounds using the same lug attached to the box. I said put it in writing and and make sure I get a copy.

250.32(B)(1) supports you, BUT…250.32(B)(2) supports him. Who is correct, only you can tell.

  • (2) Grounded Conductor
    Where (1) an equipment grounding conductor is not run with the supply to the building or structure, (2) there are no continuous metallic paths bonded to the grounding system in each building or structure involved, and (3) ground-fault protection of equipment has not been installed on the supply side of the feeder(s), the grounded conductor run with the supply to the building or structure shall be connected to the building or structure disconnecting means and to the grounding electrode(s) and shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded.*

imho:

Photos, please.

Besides, you recorded a concern, an electrician looked it over, you have filled your obligation.

tom

ewwww…now SPEEDY knows that one is a catch 22 type of reply…lol

Let me just say this…lol…I am glad that the 2008 NEC will finally address this issue…thank GAWD…

**(B) Grounded Systems.
**For a grounded system at the
separate building or structure, the connection to the grounding
electrode, the grounding and bonding of equipment,
structures, or frames required to be grounded and bonded
shall comply with 250.32(B)(1). [ROP 5–77, 5–119,
5–121a]
**(1) Equipment Grounding Conductor. **An equipment
grounding conductor as described in 250.118 shall be run
with the supply conductors and connected to the building or
structure disconnecting means and to the grounding electrode(
s). The equipment grounding conductor shall be used
for grounding or bonding of equipment, structures, or
frames required to be grounded or bonded. The equipment
grounding conductor shall be sized in accordance with
250.122. Any installed grounded conductor shall not be
connected to the equipment grounding conductor or to the
grounding electrode(s).

*Exception: For existing premises wiring systems only, the
*
grounded conductor run with the supply to the building or
structure shall be permitted to be connected to the building
or structure disconnecting means and to the grounding
electrode(s) and shall be used for grounding and bonding
of equipment, structures, or frames required to be grounded
and bonded where all the following requirements of (1), (2),
*and (3) are met: *

[ROP 5–76, 5–119]

*(1) An equipment grounding conductor is not run with the
*
supply to the building or structure.
(2) There are no continuous metallic paths bonded to the
grounding system in each building or structure involved.
(3) Ground-fault protection of equipment has not been installed
*on the supply side of the feeder(s). *

[ROP 5–119,
5–76]

Code 792 of the 457, stipulates or requires, bonding of the 354.095.987 unlessssssss the moon is in the waxing phase of cycle,… Thennnnnnn the 457 should NOT be bonded to the 792… You’ll have to re pull all the wires you just ran, bring em back to the electrical supplier and tell them to shove it! :mrgreen:

Any questions?

LOL I love electricians!!! :mrgreen: :mrgreen: :mrgreen:

Oh,… thanks Paul for the info! He He!

I should have posted the pictures in the first place. Sorry about that.

Pic #1.jpg

Pic #2.jpg

There doesn’t look like there was even a ground ran to this panel.

tom

Gerald,
I call this out all the time on sub panels,… never had an electricain (that I know about) say its ok. HEY, you did your job, its now on them.

Ok Peter…Smart A$$…lol…I was just saying that thank goodness the NEC is addressing 250.32 issues finally in regards to new construction. That post was kinda for my fellow electrician …:wink:

One important factor was missing here…if the “Sub-Panel” was in an attached garage or somewhere in the dwelling itself it would have to be done with (4) conductors regardless of what 250.32(B)(2) might allow…

But I will assume you are talking about a detached garage…lol…but I can think of many things that might stop the allowance of 250.32(B)(2)…running (4) conductors is just safer…simple as that and it is WHY the NEC is addressing it…enough of us complained over the years I guess.

If the “Sub-Panel” is indeed located in a detached garage, with no potential between the dwelling and the said garage or structure then currently a 3 wire setup is allowed by the NEC ( which is a minimum safety standard…always remember that…it is based on safety )

Now I think I see the GEC for that panel on the right…looks like a 6AWG or might be a 4AWG…can’t really tell from the picture…

Now I might question the conductors coming in…I can’t tell and I think Mark Shunk is probably a better eye than me on that…but they do not look like conductors that are allowed to run into the building itself…but alas I can’t tell on those very well…

At the end of the day…defer it and let the electrician sort it out and if he is fine with it…move on to a better fight…if the panel is attached to the dwelling or in the dwelling…then I would make it an even bigger issue personally.

Sometimes it IS perfectly legal and acceptable. As long as there are no other metallic paths, such as phone, CATV or water, then it is OK.

What I do see, or do not see, is no main disconnect.
A detached structure requires one. If the panel would accept six breakers or less, a separate, or main, disconnect would not be required. Six is the legal limit. That is an 8/16 panel.

That is URD. I know Marc’s area does not allow it but many/most others do. That is the standard wire/cable for this application in my area.

Yeah…I was not sure as it looks shinny and my area has issues with it also but I simply could not tell.

Do we know if this is a detached or attached garage…?

Anyway…Speedy did you notice the 2008 NEC change on 250.32(B)(1) …sad to say we wont see the 2008 NEC in VA well…until like 2011…lol

Yes, it is a detached garage. Underground service from the house. No ground rod outside garage, believed to continue back to the main service panel and ground to copper water service pipe.

What are you saying is legal??? The grounds and neutrals on the same buss is ok??? or not having the extra (4th) ground wire???

I know, just giving you crap! lol

Yes!!!
Yes!!!
and Yes!!!

lol…I Know…

Ok…we need clarity…lol…

Yes, under the current NEC standards…it is perfectly legal to have a 3 wire system to a detached garage IF there is no connection metalic connection between the two structures…( ie: phone line, Water Line, Concrete walkway with rebar in it, internet cables and the like )…then the NEC feels if none of those exist…then you can treat the detached garage just like a normal service…under that exception…

AS with a normal service panel and THIS exception the Grounded and Grounding conductors will share a termination on the same buss and be legal and fine in the eyes of the NEC. ( until 2008 NEC anyway…)

SO peter is correct…Yes, Yes and Yes is correct.

Now the argument HI’s will make to an electrician is that the 4th conductor makes it safer ( I believe it does actually… ) but now you have to be able to explain WHY it is safer because the electrician is viewing it from the code and the code is a minimum safety standard and all they have to install to.

Now…I will say this…IF…and IF…in that statement I read that they are running a EGC all the way back to the dwelling and to the water pipe system then HOUSTON…we have a problem…it is called a potential path…and the 3 wire setup is not an option.

Maybe I read that wrong…anyway…thats how I read the post…let me see…

nope I read it right…lol

The seperate structure also needs its own GES…and not the one of the dwelling…

Maybe and maybe not.
It will depend on the manufacture of the panel as to whether or not a main is required.
Most Main Lug panels will be marked with “Suitable as service equipment when used with integral main breaker.”
Should this panel have this on the label and it is in a detached garage it must either have a disconnect ahead of it or a main breaker.

Soooooooo
When Ive been calling out [NEC 408.20] in a downstream sub panel the neutrals and the equipment grounds must NOT be bonded together, the neutrals must “float” on the insulators that prevent contact with the metal enclosure and any equipment grounds (i.e. on the same buss) because it is a hazard.

I’ve been wrong?