Grounded & Grounding?

[bennie]

Grounded & Grounding...I personally feel the use of these words have created a lot of mis-understanding, and resultant mis-application, of connecting a ground system.

To make a point...And cause a lot of thinking and possibly trashing my perception...

What code section requires the neutral to be isolated from the equipment ground conductors in a service supplied panel (sub-panel)?

 

[charlie b]

Re: Grounded & Grounding?

OK, I'll bite. How about 408.20?

Grounding conductors shall not be connected to a terminal bar provided for grounded conductors (may be a neutral) unless the bar is identified for the purpose and is located where interconnection between equipment grounding conductors and grounded circuit conductors is permitted or required by Article 250.

 

[charlie b]

Re: Grounded & Grounding?

And while we're at it, how about 250.142(B)?

Except as permitted in 250.30(A)(1) and 250.32(B), a grounded circuit conductor shall not be used for grounding non?current-carrying metal parts of equipment on the load side of the service disconnecting means or on the load side of a separately derived system disconnecting means or the overcurrent devices for a separately derived system not having a main disconnecting means.

 

[bennie]

Re: Grounded & Grounding?

I have every code book back to 1965, and some of the handbooks back to 1940.

1968 250.23 No connection to a grounding electrode shall be made to the grounded circuit conductor on the load side of the service disconnect.

1971 250.23 The grounding electrode conductor shall be connected to the AC system on the supply side of the service disconnecting means. Grounding connections shall not be made on the load side of the service disconnecting means.

The word "electrode" disappeared from the section.

This was done by technical committee action, for purpose of technical grammar correction, stating that "grounding" implied connecting to an electrode, so the word was not necessary.

Later on, the requirements for not permitting the neutral to act as an equipment ground was added.

I am still researching this subject to find out why so many changes were made that appear to be unneccessary.

[ April 18, 2003, 05:26 AM: Message edited by: bennie ]

 

[daverz]

Re: Grounded & Grounding?

You think you're confused now.... one of the major issues being discussed among the code making panels for the 2005 NEC is to replace the words "grounding" and "grounded" with "bonding" and "bonded" throughout the code.

 

[bennie]

Re: Grounded & Grounding?

Dave: I sure hope cooler heads prevail. The NEC is supposed to reflect technology not dictate it.

Hopefully the engineering community will put a stop to such foolish action.

The credibility of the NEC will be suspect and many jurisdictions will not adopt the NEC for enforcement.

 

[Ed MacLaren]

Re: Grounded & Grounding?

replace the words "grounding" and "grounded" with "bonding" and "bonded" throughout the code.

I think you will find that the proposal referred to above will apply to what is now called the equipment grounding conductors" (EGC), and that it will greatly reduce the confusion that now exists between the functions of "system grounding" and "equipment grounding".

We made that change here (Canada) a number of years ago, and in my opinion, it helped reduce the confusion.

Of the two, only the system grounding conductor (grounding electrode conductor or GEC) is actually connected to the earth, by way of the grounding electrode system.

The EGCs, which includes metal conduits, cable sheaths, and other enclosures are bonded (connected) together and, by way of the service main bonding jumper, finally bonded (connected) to the grounded (neutral) conductor.

In fact, in order to perform their main (fault clearing) function, EGCs would not even have to be connected to the earth.

Ed

 

[charlie]

Re: Grounded & Grounding?

Ed, you are correct. Also, Panel 5 has accepted the change and, I think, the TCC will require all the panels to accept the change. My panel rejected the change with the caveat that if Panel 5 were to accept the change, we would also. I believe most of the other panels are of the same mind.

Yes, I believe it will be a little confusing for a while. Just like the rearranging of Article 250 has made it hard for others and me who knew where things were located but it became easier for apprentices to learn. This change will end a lot of the confusion everyone has with grounding. After all, look at some of the confusion in this forum.

 

[bennie]

Re: Grounded & Grounding?

I can easily understand the purpose of an equipment ground conductor, a ground electrode conductor and a bond conductor.

I do not understand a grounded, or grounding conductor.

(This sentence deleted, thanks Mike Parks)

The word "Bond" has been used for indicating shorting two conductive surfaces or material, since the beginning. It is grammatically correct terminology for joining two objects.

Keep the words, in the code, the same as in the dictionary. This will reduce confusion.

[ April 18, 2003, 11:21 AM: Message edited by: bennie ]

 

[bennie]

Re: Grounded & Grounding?

I will ask my son in law, who is a corporate attorney, if a code(rule) is legal when words are used that do not pertain to the activity.

I don't think the NEC can change the meaning of words.


I will get back on this.

 

[charlie b]

Re: Grounded & Grounding?

Originally posted by bennie:I do not understand a grounded, or grounding conductor. The words are grammatically incorrect, and do not pertain to electrical science.

I agree with your concern over the confusing nature of this selection of terms. But I must disagree with your assertion regarding grammar. Although the word ?grounded? can be used as a verb (think baseball), it can also be an adjective. Although the word ?grounding? can be a verb or a gerund, it too can also be an adjective. The English language allows us to put any adjective we desire in front of any noun we choose, thereby modifying the noun. I can use the term ?flying penguin,? and thereby name a nonexistent animal, but I would not be violating the rules of grammar.

 

[bennie]

Re: Grounded & Grounding?

Bonding is a short circuit conductor.

A ground conductor, is one that has one end electrically connected to earth, and is an inductor.

All electrical conductors are either active line, or ground conductors. A bond conductor can be on either one.
A ground conductor can not.

These two features are completely different.

Don't call an activity a duck unless it quacks.