EGC vs EBC term wise

[jwelectric]

If the term equipment grounding is changed to equipment bonding then what will the equipment bonding conductor connect to in an ungrounded delta system?

Now if you say to the grounding electrode then it must be the equipment grounding conductor again.

But if it is left the equipment grounding conductor and we keep the requirement to bond the electrode, enclosure and equipment grounding conductors at the service as it is now required then I can?t see any confusion.

 

[don_resqcapt19]

Mike,

Now if you say to the grounding electrode then it must be the equipmen t grounding conductor again.

No....the equipment bonding conductor would not directly connect to the grounding electrode. It would bond the metal parts of the equipment to the grounding electrode conductor. As I said in an earlier post, the only conductor that should use the word "grounding" is a conductor that connects directly to an electrode.
Don

 

[jwelectric]

Don

I understand what you are saying and I understand why you are saying it.
What I am saying is that due to the misconception of the purpose of the grounding electrode of cycles gone by such as in this 1968 cycle (look at (c))part of the wording found in 250.4 will need to be changed.

250.4(A) (2) Grounding of Electrical Equipment. Non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials.

As long as this section remains then the only thing that the green conductor can be called is equipment grounding (earthing) conductor.

 

[dnem]

If the term equipment grounding is changed to equipment bonding then what will the equipment bonding conductor connect to in an ungrounded delta system?

Now if you say to the grounding electrode then it must be the equipment grounding conductor again.

That reasoning doesn?t hold up to further scrutiny. . The neutral is connected to the star just as completely as the equipment conductor. . Try to use that reasoning with the neutral and what happens ?

. . What does the grounded conductor connect to in a grounded delta system?

. . Now if you say to the grounding electrode then the grounded conductor must be called a grounding conductor.

And since that?s not true, you see that reasoning doesn?t work.

But if it is left the equipment grounding conductor and we keep the requirement to bond the electrode, enclosure and equipment grounding conductors at the service as it is now required then I can?t see any confusion.

I can?t see any confusion no matter how you look at it.

Just because there's a "star" point for bonding in the main disconnect doesn't mean that all of the wires that terminate there are all the same and/or do the same job/function.

1] Service neutral [or grounded phase for corner grounded delta]
2] Load neutral conductor or bar

will both continue to be current carrying or unbalanced current conductors even tho connected to the ?star?. . They remain grounded conductors even when connected to grounding conductors.

3] Electrode grounding/earthing conductor(s)

will continue to establish zero potential to earth and make the system invisible to lightning even tho it?s connected to other wires that are doing other jobs. . It remains a grounding conductor even when connected to grounded conductor(s).

4] Equipment grounding/bonding conductor, conduit, or bar
5] Service disconnect enclosure

will both continue to provide fault current path to operate OCPD. . They remain grounding even when connected to grounded conductor(s). . They continue to provide a grounding bonding function even when connected to a conductor that provides grounding earthing function.

The absence of a grounded conductor does not affect the grounding conductors requirements, either electrode earthing or equipment bonding.

David

 

[dnem]

250.4(A) (2) Grounding of Electrical Equipment. Non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials.

As long as this section remains then the only thing that the green conductor can be called is equipment grounding (earthing) conductor.

That is a pretty screwed up way to say it. . If you think about it, the thing that has the biggest effect on voltage to ground is making sure that your neutral is properly and solidly connected to earth [obviously thru the "star" and thru the electrode].

 

[jwelectric]

That reasoning doesn?t hold up to further scrutiny. . The neutral is connected to the star just as completely as the equipment conductor. . Try to use that reasoning with the neutral and what happens ? . . What does the grounded conductor connect to in a grounded delta system? . . Now if you say to the grounding electrode then the grounded conductor must be called a grounding conductor. And since that?s not true, you see that reasoning doesn?t work. David

Here is a prime example of why more education is needed in the grounding and bonding outlined in Article 250
This ?neutral? that you mentioned above no matter if it is a delta or wye is the grounded conductor.
This word grounded is past tense of the word grounding. Grounding is present tense of the word grounded. Each word has the same meaning at different points in time.
To ground is to connect to earth no matter if you connected to earth yesterday (grounded) or if you are grounding right now (grounding) both are connected to earth.

250.4(A) (2) Grounding of Electrical Equipment. Non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials.
As long as this section remains then the only thing that the green conductor can be called is equipment grounding (earthing) conductor.

That is a pretty screwed up way to say it. . If you think about it, the thing that has the biggest effect on voltage to ground is making sure that your neutral is properly and solidly connected to earth [obviously thru the "star" and thru the electrode].

That Neutral that you are talking about above is the Grounded Conductor that is to be BONDED to the Equipment Grounding Conductors as outlined in 250.24(B).

 

[dnem]

Here is a prime example of why more education is needed in the grounding and bonding outlined in Article 250
This ?neutral? that you mentioned above no matter if it is a delta or wye is the grounded conductor.
This word grounded is past tense of the word grounding. Grounding is present tense of the word grounded. Each word has the same meaning at different points in time.
To ground is to connect to earth no matter if you connected to earth yesterday (grounded) or if you are grounding right now (grounding) both are connected to earth.

"Here is a prime example of why more education is needed in the grounding and bonding outlined in Article 250"

I'm assuming that you mean more education for CMP5 because that's who screwed up the definitions

 

[jwelectric]

I'm assuming that you mean more education for CMP5 because that's who screwed up the definitions

David

I agree that Article 250 has a lot that needs addressing. I agree that the only conductor that needs the label ?grounding? attached to it should be the one that directly connects to earth

But

This is not what the requirements of 250 states.
I believe that the requirements of 250 need addressing instead of the way grounding and bonding is taught.


A lot of what is being said and done with grounding and bonding has a lot to do with some of the old requirements of the NEC.
If I may be allowed to touch on a couple that we all can relate to I can show these misconceptions.
One is that metal water pipes in a house are to be continuous through out including jumpers across the water heater although no rule can be found to substantiate this.
I have see those that use the requirement that the connection from an electrode to the pipe be continuous and those who say that the hot and cold pipes make two different systems to try and justify a rule that doesn?t exist.

Another misconception that is sometimes seen is the installation of a rod at a pool or outside tub. Then let?s not forget the bonding of the mixing valve for the hot tub. None of these can be substantiated although a lot of inspectors will try to enforce or some electrician will call anyone that don?t do these things plumb crazy.

The rule found in 250.4(A)(2) is very clear that all metal pertaining to an electrical system SHALL BE CONNECTED TO EARTH.
This is where that we need to start addressing the equipment grounding conductor and changing the name to equipment bonding conductor.


We can keep addressing your star connection as the point of bonding and keep teaching that the equipment grounding conductor is to ground metal to earth or we can address the rule to connect everything to earth.

 

[don_resqcapt19]

Mike,

We can keep addressing your star connection as the point of bonding and keep teaching that the equipment grounding conductor is to ground metal to earth or we can address the rule to connect everything to earth.

Are you saying that we don't need a connection to earth for any part of our system?

The rule found in 250.4(A)(2) is very clear that all metal pertaining to an electrical system SHALL BE CONNECTED TO EARTH.

If you are saying that wording means that the EGC must be directly connected to earth, then there are no electrical systems that are in compliance with the code. The metal parts of the equipment are bonded to the grounding electrode conductor which is connected to earth. There is a direct electrical path, but an indirect physical path.
Don

 

[jwelectric]

Don

I agree that the verbiage used in 250 needs to be addressed. This goes without saying as the constant discussion on the matter proves.

I agree that the ways of some installations needs addressing as sorely as the terminology used by most electricians, inspectors and engineers today.

In my opinion it doesn?t much matter what you call a conductor as long there is an understanding of what is happening with that conductor.
This equipment grounding or bonding conductor could be called the low impedance return path just as easily but the function would still remain the same.

I can?t understand why what we call the conductor is the problem but I do see where the lack of education is a big problem not only with the grounding and bonding but the rest of the book as well.

Ever sense the introduction of equipment grounding (earthing) the rule has been to connect all metal parts of a system to earth as is outlined in 250.4(A)(2) today.

Where most of the confusion comes into play is through the bonding of these items together at the service.

To comply with 250.4(A)(2) I could drive a rod at every receptacle and switch in a house and connect to the rod and be done or just run a wire from each to one rod and be done.

This would leave me in violation to the next section of the same section, (3) Bonding of Electrical Equipment. Non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path.

What I am saying is;
in order to get the term ?Equipment Grounding Conductor? changed to ?Equipment Bonding Conductor? something will have to be done with the wording found in 250.4(A)(2) which clearly states that the equipment grounding conductor is to be connected to earth.
We all know that this connection is accomplished with the bonding of the grounded (neutral), equipment grounding conductor, service disconnect and the grounding electrode with the ?Main Bonding Jumper.?
To delete 250.4(A)(1) from the code would leave the door open to changing the name of the EGC to EBC. The rule in 250.4(A)(3) would still serve to accomplish the bonding of the metal parts of the system.

Now that all this is covered;
How would this affect 250.4(B)?

 

[don_resqcapt19]

Mike,
I see no reason to change 240.4 to make the change in the name of the EGC. That is because that conductor does not connect to earth or a grounding electrode. It is bonded to a conductor that provides that function. The problem with the existing wording that it leads some to believe that all the EGC does is make the connection to the earth. While it does that via the bond to GEC, that is not a very important part of the function of the EGC. Its most important function is the fault clearing path. We will have to agree to disagree on this one.
Don

 

[jwelectric]

Don
I don?t think that we disagree on anything but the way it is being said.

You say that the Equipment Grounding Conductor does not connect to earth or an electrode but instead connects to a bonding jumper that bonds all this together.
If this is what you are saying I am in full agreement.

I am saying that 250.4(A)(2) and (B)(1) ?requires? that anything that the Equipment Grounding Conductor is terminated on be connected to earth to stabilize the voltage to earth.

250.130 clearly states how I am to connect the items mentioned in 250.4 (A)&(B) to earth.
(A) For Grounded Systems. The connection shall be made by bonding the equipment grounding conductor to the grounded service conductor and the grounding electrode conductor.

In my honest opinion if the requirement in 250.4(A)(2) and (B)(1) were removed 250.110 could be left as it is and the word ?grounded? could be changed to ?bonded? throughout article 250 without any problem.

 

[George Stolz]

Mike, I've just read through this thread and I do not see why you are reaching the conclusions you are.

At the moment, the code is designed in a mirror image to what you propose it should be. Bonding is mentioned in 250.4, with equal footing to grounding; yet it is called an EGC - almost as if a coin was flipped to determine with half of the requirements the conductor should namesake.

If it were to be called an EBC in the 2011, why would we have to eliminate the "grounding" requirement?

Do we currently ignore the "bonding" portions of 250.4? Should we? Obviously not.

I do not understand the significance of the ungrounded delta in this discussion - ungrounded systems are clearly addressed in 250.4(B).

This word grounded is past tense of the word grounding. Grounding is present tense of the word grounded. Each word has the same meaning at different points in time.
To ground is to connect to earth no matter if you connected to earth yesterday (grounded) or if you are grounding right now (grounding) both are connected to earth.

This is meaningless - all these conductors were connected to earth yesterday, will be today, and if all goes well, will be connected tomorrow.

Are these terms unnecessarily similar and confusing for new users of the code? Darn right they are. New users of the code are forced down the same path that the older users are: mindless memorization of the meanings of each conductor.

If some sort of rationale for the terminology aids in that goal, so be it. But the rationale presented is not logical.

JMO,

 

[dnem]

reply to George post #33

Great post !

You made points that I wanted to make but I couldn't figure out how to say what I wanted to say.

David