Thread: Grounding

Could someone please comment on whether it is acceptable to use the service entrance cable braided aluminum wire for grounding in this manner. I have always seen a separate ground wire installed for grounding.

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I don't see where the left and right bus bars are bonded to each other. The plastic ring on the end of the SEC conduit is also absent.

Is this the main panel or a remote distribution panel? The neutral and ground wires are separate and four wire feed is present.

Sorry. This is a main panel.

Originally Posted by Scott Latosky

Sorry. This is a main panel.

Ambiguous questions can foster ambiguous responses.

I don't care if this is the main power panel for the structure/building/occupancy vs. load-side distribution panel within a occupancy that doesn't necessarily "tell" me anything - a distinction without necessarily a difference at this point.

I first care if this is the SERVICE equipment or not, and if not - where the Service equipment IS (on same building, remote structure, pedestal, etc.). It does not appear to be service equipment - it appears to be fed by a 4-wire main power feeder. Now I care if the Service is first TO this building/structure.

I also care if the equipment is rated for CU, AL, or both, and if this equipment is rated for 60C, 60/75C or 75C (main breaker is 100A). I care where this inbound feeder supplying this panel originates indoors (60C limitation for the allowable ampacity use of this cable) or outdoors, same building or structure, different structure, pedestal or pole.

Where is the (POCO inbound otherwise uninterrupted) SERVICE disconnect and is that inside or outside the thermal envelope (some cables limited to 60C when both "ends" are indoors)? This does NOT appear to be it (service entrance).

What type of occupancy is this? Where is the meter and POwerCOmpany Service Disconnect?

Where are the grounding electrodes and grounding electrode conductors?
I suspect this is not truly the service equipment. Do a search here on "sub panel" and read through some of Jerry's rants and detailed explanations to get a better idea of the difference.
(sorry Jerry, just the best way to get him to the appropriate threads)

Its kind of a pain in the backside to be forced to look up and review all your prior posts to determine where in the WORLD you might be located.

I notice reference previously to having been in PA.

Please update your profile to indicate where in the world, and where in N.A. if that applies, you're AT and practice. (Distinctly different requirements and practices for example in the better part of Canada, for example, regarding separation of EGCs and grounding conductors even in "service equipment", etc.). It will also help when addressing other questions for other topic areas, in which regional practices and/or geographical (climate, seismic, etc.) location may affect the responses.

Thanks in advance for your cooperation.

Hi Scott,

Is this a townhouse or condo perhaps? The way that panel is wired, and fact that you've got a 100 amp main breaker back feeding the panel suggests that it is -- that's the way they do it in my area.

If you look at the ground bar on the right side of the panel, you will notice the bar is bonded to the panel (look at the center area of this bar), as it should be.

If you look at the neutral terminal bar, you will probably notice that it is floating, aka. not bonded to the panel. That's how it has to be done for non service equipment.

See that screw securing the 100 amp breaker (main breaker in the panel) in place? (back fed panel) That's so the breaker can not pop out of place. If that breaker were to come out of place, you would have a dangerous situation with a hot, loose breaker inside the panel.

If I am correct and this is a townhouse/ condo, you will find a meter bank on the outside of the building, with breakers to cut power to each unit-- that's your service equipment (meter main). If it's just a house, it would still be wired the same, you'll just see one meter instead of an entire bank.

At the outside main (or perhaps inside on a larger structure) you will find the true GEC (grounding electrode conductor/ ground wire/Ufer).

Sorry, just reiterating what everyone else said in a more simplified manner. Don't really know how much experience you have with electrical systems........

The above posters are quite correct - we need to know if this is "service equipment" or is this a panel which is "not service equipment" as there is an important distinction between them on where and how the neutral and grounds are connected.

Originally Posted by Brandon Whitmore

Is this a townhouse or condo perhaps?

If I am correct and this is a townhouse/ condo, you will find a meter bank on the outside of the building, with breakers to cut power to each unit-- that's your service equipment (meter main).

That would be correct for a condo, but that would be incorrect for a townhouse.

My bad. I am in PA and will update my profile. I had to run back out to the property (condo) to look at this electrical item. I overlooked the fact that this is a secondary panel. Much appreciated.

Originally Posted by Scott Latosky

I had to run back out to the property (condo) to look at this electrical item. I overlooked the fact that this is a secondary panel.

With that knowledge (that it is: 1) a condo; and 2) not service equipment) then the grounds should go to the right side terminal bar, which is bonded to the enclosure, and, the neutral should go to the left side neutral terminal bar which is mounted on plastic standoffs and which is not bonded to the enclosure ... as shown in your photo.

There is a "main" for that panel, but that is not the "main service disconnect", it is just a "panel main" which allows the occupant to shut off all power to the condo with one disconnect - I actually prefer this "panel main" arrangement even though there is no requirement for it ... to me it provides an increased safety factor.

Note that in your first photo there is a white conductor being used as a hot conductor, this white conductor needs to be re-identified to black or red (preferably red as there already is a black for that 240 volt circuit) and this needs to be done at this panel and at all locations where that white conductor is visible and accessible (i.e., at junction boxes and the other end of that conductor).

I see NM cables stacked (bundled and not maintaining spacing) for more than three conductors (there are 2 two conductor cables for four current carrying conductors) and if condition exists for more than 24", and, if these conductor run up into an attic (if this was a top floor condo), then derating would need to be applied. If only the 4 current carrying conductors were the problem and ambient temperature is not (not in an attic), then the derating would not affect anything as far as overcurrent rating size goes.

Thank you all for replying to my post. As always it is very much appreciated.

Roger, great diagrams! I have a couple of questions.

If the distribution (sub) panel is a remote panel, like a detached garage, is a ground electrode required at the remote panel?

When did it become required by code? Important for me to know as I can't recommend correction if it was code compliant when constructed. (I can make suggestion though)

What distance from the main structure before it becomes a requirement?

If the remote panel is fed by a three wire service from the main service, two hot and one neutral, can a seperate ground wire be run to the remote panel to bring it up to current code?

Originally Posted by Vern Heiler

If the distribution (sub) panel is a remote panel, like a detached garage, is a ground electrode required at the remote panel?

Yes a grounding electrode is required at a remote or detached building anytime it is served by more than one circuit. A MWBC counts as one.

When did it become required by code? Important for me to know as I can't recommend correction if it was code compliant when constructed. (I can make suggestion though)

What distance from the main structure before it becomes a requirement?

This has been required for years. This is no minimum distance.

If the remote panel is fed by a three wire service from the main service, two hot and one neutral, can a seperate ground wire be run to the remote panel to bring it up to current code?

This would probably only be possible in a conduit application since all conductors must be run together. You would still need space in the conduit for the additional conductor.

Originally Posted by Eric Barker

The plastic ring on the end of the SEC conduit is also absent.

The bushing is not required. The fitting provides a smooth rounded edge.

Originally Posted by Roger Frazee

Jerry .... Did you ever play "Find Waldo" well lets play find 'sub-panel' ........

Roger,

I see the periscope, but the sub is not in torpedo range yet, I doubt the panel would float to the surface for me to find it ...

VERY nice drawings.

The thing which stuck out to me on those drawings were the current flow arrows.

They should be bi-directional arrows showing current in either/both directions, but for teaching aids I doubt anyone would think of DC when in the class room, and if they did, you would be there to point out that it is just representative of "the path" the current is flowing and that the current will flow both direction on "the path"..

Originally Posted by Vern Heiler

Roger, great diagrams! I have a couple of questions.

If the distribution (sub) panel is a remote panel, like a detached garage, is a ground electrode required at the remote panel?

When did it become required by code? Important for me to know as I can't recommend correction if it was code compliant when constructed. (I can make suggestion though)

What distance from the main structure before it becomes a requirement?

If the remote panel is fed by a three wire service from the main service, two hot and one neutral, can a separate ground wire be run to the remote panel to bring it up to current code?

Hi Vern

Jim answered most of your questions but let me just add to them a bit. The drawings that I posted are for a panelboard installed in the same structure as the service equipment, which negates any requirement for a connection to a grounding electrode system at the panelboard.

As Jim said any panelboard installed in a detached structure/building fed by a feeder will require at connection to a grounding electrode system.

But there is one important exception for detached structures. When you supply a detached structure with a single branch circuit 2 wire 120 volt or multiwire branch circuit with a wire type equipment grounding conductor as required in 250.118 it is not required to establish a grounding electrode system at the detached structure or to connect to an existing one.

These rules apply to detached structures that are not dwellings.

I honestly do not know when it became code but I believe it has been several decades.

There isn't a distance as such that I am aware of as long as it is detached from being part of the structural entity of the dwelling. Spanning between the dwelling and structure with a 2x4 is not being attached. I once had an electrician tell me that is all you had to do to get around the grounding electrode system if your installation required it.

A 3 wire feeder to a detached structure other than a dwelling is allowed pre 2008 but I would agree with Jim. Just remember there are some exceptions before you can run a 3 wire feeder to a remote panelbaord in another structure from the service equipment.

Yes you can add an equipment ground (and I agree here with Jims comments) but you will have to unbond the neutral and ground in the panel fed by 3 wires (H-H-N).

Remote structure not necessarily a remote building.

I think what's being asked, Roger, is how far before it is considered a remote structure, or might require a supplimental made electode or bonding, such as a Heat pump and its disconnect installed remotely from a building, a water well pump "house", etc.

Good evening Hg I thought I was the only one up this late ...

I'm pretty weak in the supplementary electrode requirements and in their application so I am going to have to defer to your knowlege in that area. I thought Vern was just asking how far a garage for example would have to be from the dwelling before it is considered detached.

Opps sorry thought you said supplementary not supplemental

Originally Posted by Scott Latosky

My bad. I am in PA and will update my profile. I had to run back out to the property (condo) to look at this electrical item. I overlooked the fact that this is a secondary panel. Much appreciated.

Still didn't get around to updating the profile yet? I assume it is a time thing, and figuring out how to get to the edit profile page, so I'm throwing instructions on how to get there for you:

After you've logged in you'll see at the top of the page the choices on the dark blue background menu bar/banner just under the InspectionNews logo changes when you've completed the log-in process. The choice at the furthest left (reversed/white from the dark blue banner) will now read "User CP" (Control Panel). Click on that,

That will take you to the Control Panel page.

Menu on the left of that page first category heading is "Settings and Options", third sub heading down under "Settings and Options" is "Edit Profile" Click on that.

This will open the Edit Profile "boxes" in the center of the page Titled "Required Registration Information". The second "box" down is "Location".

HTH.

Originally Posted by Roger Frazee

Good evening Hg I thought I was the only one up this late ...

I'm pretty weak in the supplementary electrode requirements and in their application so I am going to have to defer to your knowlege in that area. I thought Vern was just asking how far a garage for example would have to be from the dwelling before it is considered detached.

Opps sorry thought you said supplementary not supplemental

Oops, yep I did but you thought what I thought, I just didn't say/type/spit it out correctly. Nope, you're not the only one who's on or up.

Originally Posted by H.G. Watson, Sr.

Oops, yep I did but you thought what I thought, I just didn't say/type/spit it out correctly. Nope, you're not the only one who's on or up.

I know the feeling when trying to get the fingers to say what the mind wants them to....

Anyway gotta rise early in the morning so I'm going to put the ole puter in standby and lay down for a bit.

Have a good evening.

Originally Posted by H.G. Watson, Sr.

Remote structure not necessarily a remote building.

I think what's being asked, Roger, is how far before it is considered a remote structure, or might require a supplimental made electode or bonding, such as a Heat pump and its disconnect installed remotely from a building, a water well pump "house", etc.

There is no distance restriction. It can be 3 inches from the main building/structure but if its not attached then its remote / separate structure
If it is not attached permantly to the main building / structure AND is fed with a feeder OR branch circuits. then it is required to have a grounding electrode installed.
Keep in mind a multiwire branch circuit is considered 1 circuit in this case.
So if your well pump house only has 1 circuit in it then it only requires the equipment grounding conductor that is ran with that 1 circuit

Originally Posted by Roger Frazee

Hi Vern

A 3 wire feeder to a detached structure other than a dwelling is allowed pre 2008 but I would agree with Jim. Just remember there are some exceptions before you can run a 3 wire feeder to a remote panelbaord in another structure from the service equipment.

Yes you can add an equipment ground (and I agree here with Jims comments) but you will have to unbond the neutral and ground in the panel fed by 3 wires (H-H-N).

Just to make sure I've got this right:

1) Ground electrode has been required at remote panel as long as can be remembered.

2) Three wire feed to remote was ok until 2008.

3) You can add equipment ground wire, but it has to be bundled with the hot and neutral wires?

4) Would the neutral and ground be bonded at the remote panel in a pre 2008 three wire service? I thought it would still be isolated.

The reason I want to be clear on #3 is, if I run into a need for adding an equipment ground wire, the first thing the customer wants to know is "how much trouble or cost will it be". If I know the old feed has to be dug up and replaced or have a wire added, I can give him the ol eye roll and say "I think it has to be dug up and fixed". If a separate wire can be added, I can tell him "It might not be that big of a project". I still leave it up to the electrician to determine, but it gives the customer a better feel for what might be comming.

With the older 3 wire feeder to an outbuilding the neutrals were again bonded with the grounds. One of the stipulations of the 3 wire feeder was that there be no other metalic paths like a phone or water line back to the other building.

]

Just to make sure I've got this right:

1) Ground electrode has been required at remote panel as long as can be remembered.

In my case anyway ...

2) Three wire feed to remote was ok until 2008.

Yes aas far as the NEC but it is possible that your state or local authority required 4 wire feeder and banned 3 wire feeder before 2008. Example is State of Washington they have disallowed a 3 wire feeder long before 2008 NEC.

3) You can add equipment ground wire, but it has to be bundled with the hot and neutral wires?

Yes unless you have a listed metal conduit to serve as ground.

4) Would the neutral and ground be bonded at the remote panel in a pre 2008 three wire service? I thought it would still be isolated.

No if your feeder is 3 wire you must bond neutral and ground in the panelboard. The neutral of the feeder must also act as the effective ground fault path back to the service equipment then to the utility transformer center tap.... since with 3 wires there is no 4th wire ( equipment ground ) to serve that purpose.

There should be no requirement to upgrade to 4 wires if a 3 wire feeder was installed. I would take a guess that there are thousands more 3 wire feeders than 4 wires in existence. 4 wire feeders are to a degree safer than 3 wire feeders and I would recommend upgrading to 4 wires. I also would not lose any sleep with a properly installed 3 wire feeder.

Lets try another drawing. I've got a 3 wire feeder to a panel load side of the service equipment, if I isolate neutral and ground like the drawing illustrates then how would any fault current get to the center tap of the transformer ? In the drawing I would have to connect (bond) that equipment ground in the branch circuit to the neutral bus in order for fault current to use the feeder neutral as part of the effective ground fault path to facilitate any fault current to reach the service equipment then out the service neutral to the transformer. If I do not do this and a ground fault occurs then a breaker will not trip and all metal in the fault path including the metal of the panel will come to line voltage.

OK H.G., lets git this one going...
Define 'separate stucture'.

Originally Posted by bob smit

OK H.G., lets git this one going...
Define 'separate stucture'.

First of all, I didn't use the phrase "separate structure", so play with or pick on or argue with someone else, perhaps one of the three who used the phrase in this thread.

There is no reason for ME to DEFINING anything, especially upon YOUR demand. NO REASON.

I made point of saying a remote structure is not necessarily a remote building. You apparently have "who said what" confused.

Second, K.H. unattached still not necessarily required to be treated as a remote structure. Can be covered by projection/roof of another structure and still be considered part of, yet not "attached" but may be connected, i.e. other metallic path for example.

Depends on the adopted codes and/or ammendments of the jurisdiction, and the code cycle relevant to the installation.

I suppose I am guilty of using the term structure and building all in the same breath...

The NEC defines structure as that which is built or constructed. My understanding is that is to allow engineers, architects, general contractors etc to follow the same definition whatever that means. I've never really understood how to separate the term out so as to be 'different' from a building. To me a structure could be as simple as a pole with a service disconnect mounted on it.

I would very much like Hg, Bob, or Jerry whomever to explain the differences to me. A little off subject though. I could start a new thread if that would be a better. It will have to be latter this evening though.

Originally Posted by Roger Frazee

I suppose I am guilty of using the term structure and building all in the same breath...

The NEC defines structure as that which is built or constructed. My understanding is that is to allow engineers, architects, general contractors etc to follow the same definition whatever that means. I've never really understood how to separate the term out so as to be 'different' from a building. To me a structure could be as simple as a pole with a service disconnect mounted on it.

Roger,

Structure. That which is built or constructed.

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.

A strip shopping center is one "structure", but could be many "buildings".

One could have two overlapping *separate* and *not connected* "structures" and require each to be treated as "separate structures", unlike H. G.'s description of two overlapping *but not separate even though not connected* "buildings".

Originally Posted by H. G. Watson

Second, K.H. unattached still not necessarily required to be treated as a remote structure. Can be covered by projection/roof of another structure and still be considered part of, yet not "attached" but may be connected, i.e. other metallic path for example.

If unattached, they would be "separate structures". H. G. brought up a condition in which "separate buildings" are not "separate" "buildings".

The words "building" and "structure" are not interchangeable in that sense.

For the building codes the difference between a "building" and a "structure" are entirely different. In the building codes anything that which is built is a "structure", as in your example of the temporary power pole. A "building", however, is a "structure" which is designed for human occupancy.

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.
- STRUCTURE. That which is built or constructed.

From the IBC:
- BUILDING. Any structure used or intended for supporting or sheltering any use or occupancy.
- STRUCTURE. That which is built or constructed.

I wasn't picking on U H.G., nor did I assume your required to respond.
You were however, vocal in the morphing that was taking place in this thread toward the building/structure debate to follow.

I knew U would take the bait: wz meant as semi-complement with J.P. soon to follow.
Why? Well since as an AHJ myself, I find occasion where this subject arises and therefore wanted to recreate the discussions for better insight for me as well as others.

As said before, this could be a new thread,....my bad.

Originally Posted by Jerry Peck

Roger,

Structure. That which is built or constructed.

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.

A strip shopping center is one "structure", but could be many "buildings".

One could have two overlapping *separate* and *not connected* "structures" and require each to be treated as "separate structures", unlike H. G.'s description of two overlapping *but not separate even though not connected* "buildings".



If unattached, they would be "separate structures". H. G. brought up a condition in which "separate buildings" are not "separate" "buildings".

The words "building" and "structure" are not interchangeable in that sense.

For the building codes the difference between a "building" and a "structure" are entirely different. In the building codes anything that which is built is a "structure", as in your example of the temporary power pole. A "building", however, is a "structure" which is designed for human occupancy.

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.
- STRUCTURE. That which is built or constructed.

From the IBC:
- BUILDING. Any structure used or intended for supporting or sheltering any use or occupancy.
- STRUCTURE. That which is built or constructed.

Jerry

Thank you for the excellent breakdown of the differences. I've been struggling for a long time over this structure definition and it is great to finally have a much better understanding.

'cept I didn't say "separate", I referred to "remote". not the same thing. I was not referring to "overlapping buildings", I was referring to a building which provided cover to a structure which was not necessarily "remote".

Now how did I know that this debate would surface in this thread ?

I ignored the "remote" term as it is an undefined term which is NOT applicable to the discussion, it is just "flak" thrown up into the air to get in the way. It does not matter whether a structure is 0.01 inches "remote" from another structure or it is it 1 mile or more "remote" from another structure.

What matters is whether or not it is one structure or "separate" structures - all that flak not withstanding.

See, this is what I'm talking about. Now I'm confused again.
My understanding is that one of reasons for the establishing of earth electrodes is to make sure surrounding conductive surfaces are at the same potential as the surrounding earth. Note that I stated 'one of the reasons'.

This idea in mind would seem to be more of an issue as the separate structure is more or less remote. Oops, I said remote.

Remote and separate are not defined in the NEC, and this is an NEC discussion.
When a term is not defined in the NEC one must refer to another reference to obtain the definition.
This othe rsource is : The Dictionary.

According to Websters Dictionary and the Random House College dictionary:

Remote = Far Apart; Far distant in space , Out of the way secluded ,

Separate = To keep apart as by an intervening barrier or space.

So as I stated and Jerry also stated, if NOT attached its a separate structure. (Yes that separate structure can be a "remote" structure if its far away from the first one)

Keep it simple !

Originally Posted by ken horak

Remote and separate are not defined in the NEC, and this is an NEC discussion.
When a term is not defined in the NEC one must refer to another reference to obtain the definition.
This othe rsource is : The Dictionary.

According to Websters Dictionary and the Random House College dictionary:

Remote = Far Apart; Far distant in space , Out of the way secluded ,

Separate = To keep apart as by an intervening barrier or space.

So as I stated and Jerry also stated, if NOT attached its a separate structure. (Yes that separate structure can be a "remote" structure if its far away from the first one)

Keep it simple !

Actually that's not true.

The NEC refers to terms which are defined in other codes and resources, several of which are also NFPA publications, many ANSI standards, and several which are published by other organizations. These are checked FIRST, before resorting to a dictionary, but after checking the individual Article, Chapter Part, or Chapter for specific definitions or explanations and the NFPA Style Guide edition applicable to the NEC publication, should the NEC have been adopted without any ammendment locally, whatsoever. Some editions of various codes cite different dictionary references.

Generally, however, the local authority has adopted its own series of codes, as ammended, modified, and more often than not has its own heirachy of resource terms.

The presence of a "firewall" is not required to define a building. The NEC does not define a "firewall", neither does IIRC the IRC (which defers to the IBC for example, first, for defintions, before other sources). SPACE is one method of providing a separation, a fire resistive assembly is yet another means to separate, differing of construction requiring more or less "space" between them. AIA is deferred to by the NEC, as are other resources AHEAD of a dictionary reference, including Life Safety, Fire, Zoning, Building Codes to name a few.

Wonder why Roger deleted so many of his posts on this topic.

Originally Posted by H.G. Watson, Sr.

Wonder why Roger deleted so many of his posts on this topic.

I believe there was some discussion over liability if some idiot electrocuted himself or his family members from using Roger's drawings to wire his house.

Originally Posted by John Kogel

I believe there was some discussion over liability if some idiot electrocuted himself or his family members from using Roger's drawings to wire his house.

No, but the *possibility* of that happening was discussed ... and Roger understood that *possibility* was indeed there and therefore withdrew those drawings to avoid that possibility.

To my knowledge, that had not happened to Roger as yet, Roger was just getting ahead of that and stopping it from happening.

Originally Posted by H.G. Watson, Sr.

The NEC refers to terms which are defined in other codes and resources, several of which are also NFPA publications, many ANSI standards, and several which are published by other organizations. These are checked FIRST, before resorting to a dictionary,

"These are checked FIRST, before resorting to a dictionary"

Close ... but no SEE-gar.

Scope. This article contains only those definitions essential to the proper application of this Code. It is not intended to include commonly defined general terms or commonly defined technical terms from related codes and standards. In general, only those terms that are used in two or more articles are defined in Article 100. Other definitions are included in the article in which they are used but may be referenced in Article 100.

If a general term has a common definition, that applies; if a technical term has a common definition, that applies; except for the definitions stated in the NEC - the NEC definitions supersede any and all other definitions as used in the NEC articles and subsections.

Unlike the ICC codes which give a specific reference guide point:
- R201.3 Terms defined in other codes. Where terms are not defined in this code such terms shall have meanings ascribed to them as in other code publications of the International Code Council.
- R201.4 Terms not defined. Where terms are not defined through the methods authorized by this section, such terms shall have ordinarily accepted meanings such as the context implies.

Florida gets even more specific:
- 201.3 Words not defined. Words not defined herein shall have the meanings stated in the Florida Building Code, Plumbing , Mechanical and Fuel Gas, or the Florida Fire Prevention Code. Words not defined in the Florida Building Codes shall have the meanings in Webster's Third New International Dictionary of the English Language, Unabridged.

Florida even tells you which edition of which dictionary applies for words not defined IN THE FLORIDA codes.