Seperate ECG

[Marc M]

Jerry,
I understand that when there is a separate building with a separate panel that is NOT connected by any shared metal systems, pipes etc... no EGC from main, this building then gets its own ECG. What about a situation where a remote panel board is located in an area other than a building, such as a yard? Separate ECG still apply?

[Jerry Peck - Codeman]

Hi Marc,

The pole/pedestal/supports-of-whatever-type-they-may-be is the "structure" by definition of what a "structure" is:
- From the NEC: "Structure. That which is built or constructed."
- From the IRC: "STRUCTURE. That which is built or constructed."

The older versions of the NEC, I believe it changed with the 2005 NEC, allowed two scenarios depending on whether or not there was any metallic paths, of any type, between the structures and which could under any condition (planned or unplanned) create an electrical path between the structures. If there was no electrical path, separate ground was not required (i.e., the feeder could be a 3-wire feeder), but if there was an electrical path, then a separate ground was required (i.e., the feeder was required to be a 4-wire feeder).

In 2005, I believe it was 2005, the code changed that regardless if there were, or were not, any metallic paths between the structures, the feeders to the other structure was now required to be a 4-wire feeder.

Now, let's go to another term which is sometimes used interchangeably for the word "structure": "building".

A "building" is a "structure", but a "structure" is not always a "building": (underlining and bold are mine)
- From the IRC: "BUILDING. Building shall mean any one- and two-family dwelling or portion thereof, including townhouses, that is used, or designed or intended to be used for human habitation, for living, sleeping, cooking or eating purposes, or any combination thereof, and shall include accessory structures thereto."
- From the NEC: "Building. A structure that stands alone or that is cut off from adjoining structures by fire walls with all openings therein protected by approved fire doors."
- From the IBC: (in case you are not using the IRC) "BUILDING. Any structure used or intended for supporting or sheltering any use or occupancy."

Basically, building codes address more aspects than the NEC, and the difference between a "structure" and a "building" is that a "building" is any "structure" which is used for, or intended to be used for, any type of human occupancy.

A mailbox is a "structure" but is not a "building".
A barn is a "structure" and is also a "building".

[Marc M]

Got it, I hate the grey areas. Thanks for your time.

[Marc M]

Okay, just to be clear...
If the main service panel board serving a remote panel board does not include an EGC, and does not connect the two panels with a similiar bond such as EMT or ?, then that remote panel should then and can create its own grounding system e.g. rod and then can bond the grounded/ing buses direct to the panel board..

[Jerry Peck - Codeman]

Okay, just to be clear...
If the main service panel board serving a remote panel board does not include an EGC, and does not connect the two panels with a similiar bond such as EMT or ?, then that remote panel should then and can create its own grounding system e.g. rod and then can bond the grounded/ing buses direct to the panel board..

"Okay, just to be clear..."

Rather, just to be as clear as mud ... because it is not clear, there are too many 'except if' alternatives to be clearly stated as a given anything.

a) Regarding the grounding electrode system (setting aside the neutral question for the time being), *each* building or structure supplied by feeders or branch circuits shall have a grounding electrode system installed under the same rules applicable to the first building or structure which is supplied by the service ... unless ... unless the 'other' building or structure is supplied by only a single branch circuit or a single multiwire branch circuit - and - that branch circuit includes an equipment grounding conductor (which is not being used as a neutral).

Now that that is as clear as mud ...

b) The 'other' building or structure, the one supplied by feeders or branch circuits from the first building which as the service equipment, the 'other' building or structure shall be fed with a circuit which contains a grounded conductor (neutral) and a grounding conductor, along with the one or two hot conductors (one for a 120 feed and two for a 240 volt feed or a 120 volt/240 volt feed) ... unless ... unless the 'other' building or structure is an existing building or structure which was wired prior to the rule change which now requires the separate grounded and separate grounding conductors - and - this grounded conductor is permitted to be connected to the grounding electrode system and shall be used as the equipment grounding - and - an equipment grounding conductor is *not* run with the feeders or branch circuit to the 'other' building or structure - and - there are no continuous metallic paths between the separate buildings or structures - and - GFCI protection has *not* been installed on the supply side of the feeders or branch circuits.

Now that that is as clear as mud ...

The grounded conductor (neutral) is only allowed to be connected (bonded) to the grounding electrode system at the 'other' building or structure under the "unless" condition in b) above - otherwise the grounded conductor (neutral) is isolated from the grounding electrode system and the equipment grounding system.

Not sure if I made the answer more clear or if I muddied it up even more?

[Marc M]

I actually completely understand all of what you wrote, it's easy to understand once put in simple terms. I have only one question believe it or not, and it's likely to expose my ignorance here, but here it is; for some reason I don't get the comment and - GFCI protection has *not* been installed on the supply side of the feeders or branch circuits.
. It seems obvious, but can you paint an image of what this may look like. Thanks

[Jerry Peck - Codeman]

for some reason I don't get the comment and - GFCI protection has *not* been installed on the supply side of the feeders or branch circuits.
. It seems obvious, but can you paint an image of what this may look like. Thanks

I'll try as I am applying my logic to the reason for not allowing GFCI protection to have been installed at the supply.

The GFCI is monitoring the current through the hot and neutral conductors, and any off balance of that current would be caused by the difference in current going through something or someone to ground, i.e., an example would be 10 amp through the hot conductor should equate to 10 amps in the neutral conductor, anything less than 10 amps in the neutral conductor means that difference is going 'someplace, anyplace, else', which is not good.

In the case of 250.32(B) Exception which allows for existing installation to not have a separate ground and a separate neutral conductor, that difference current is still on the neutral conductor as that grounded conductor is serving a dual purpose of grounded and grounding conductors, which means the GFCI will not, at least may not, trip, and the expected level of protection of the GFCI would not be there. One may see the GFCI and think there is GFCI protection when in fact there is no GFCI protection in this case - that illusion could allow a deadly situation to arise and result in serious electrical shock and injury, or possibly electrocution (death).

Does that make sense?

[Marc M]

Yea I really do get what you're saying, but I think I'm confused on the words "supply side of the feeders". Don't they mean the same thing?
And are they suggesting the GFI is a receptacle or disconnect?

[Jerry Peck - Codeman]

"supply side of the feeders"

With the GFCI on the supply side of the feeders, what I described could make the GFCI non-effective because it may not trip. Remember, this installation is using the grounded conductor (neutral) also as the grounding conductor, like is done with service entrance conductors, and you install GFCI protection on the load side, not the line side at the transformer.

With the GFCI on the load side of the feeders, at the panel is the other building, that problem would not be present as the GFCI would be acting and serving the same as it does in the first building (it is protecting the branch circuits or just what is plugged into the receptacle as a GFCI receptacle device).

That is why the code specifies not on the supply side of the feeders - the GFCI on the load side is okay.

[Marc M]

Oooo, okay I get it now. It just clicked, Thanks.

[Marc M]

I was lucky enough to have an inspection today on a house with a remote panel in the garage. So in this image, can the EMT serve as the connection to ground (via grounding bushing)? Thus not requiring its own GEC. Providing the GFI is not installed service side.

[Jerry Peck - Codeman]

Yes, and GFCI protection could be installed on the supply side because there is a separate grounding path (the EMT) - provided the EMT is continuous or connects to another metallic raceway such as RMC or IMC (EMT is not allowed to be buried and that supply comes up from the bottom, indicating it is from underground), and I would not count on that as it may be in PVC underground - which means the 'yes' would be a 'conditional yes, if ... '. Of course, that may be rigid or intermediate and not EMT, you were there and would know the answer to that.

They also spray painted the grounded (neutral) conductor white and that is not allowed for that size conductor (should have pulled in a white conductor).

They also have some screwy wiring going on in there:
- from the top through the back is a white and black (no ground and looks like flexible cord) with the black going to one side of that double pole breaker (that part is okay)
- from the top right there is a white, blue, and a red, with the EMT as ground (presumably, not guaranteed though), and the blue conductor goes to the separate breaker on the upper left with the red going to the other side of the double pole on the lower right - if that is a multiwire circuit then it is wired incorrectly (needs to be taped off opposite bus bar phases and it looks not to be, also now needs a double pole breaker with a handle tie or internal trip), if it is a 120 volt/240 volt circuit then it is wired incorrectly (needs to be on a double pole breaker with a handle tie or internal trip).

Electrical contractor needs to sort that out and correct everything thing which they find to be incorrect (including the spray-painted-white conductor).

[Marc M]

Very good, thanks a million.
Hey Jerry, just wondering if you attempt to call out every single issue individually in your report or combine all in one general summary of conditions including see electrician yada yada....

[Jerry Peck - Codeman]

I start listing them, then I just call for the electrical contractor to "correct all items in the panel, including, but not limited to -list the items I already found- and any other items they find or create", because in correcting some items they may create new items.

[Marc M]

That's actually what i do and it seems my reports are considerably longer than most of my competitors. I'd say a larger percentage of the local HI's here will just make a blanket note that there are issues in the panel..."go see an electrician". I mainly list the issues because its (IMO) what my clients are paying for + I hate the RE call backs. " What exactly was wrong in the panel", my electrician wants to know what it was you saw in there" etc... I figured that's how you did it also, just curious..