Definition

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bennie

Esteemed Member
I see that another attempt has been made to change the term "equipment ground" to bonding.

The proposal was soundly rejected and rightfully so. I have a real problem with any one, in the trade, who keeps trying to change the words in the code book.

An equipment ground wire is an inductor. A bond wire is a short circuit.

Never mix the two.
 

tom baker

First Chief Moderator
Staff member
Re: Definition

The problem is to ground" is to connect to a earth ground or conducting body that serves in place of the earth. Art 406 says to ground a receptacle but what we do is bond it to a low impedance path, and essentially we creat a short circuit to facilitate the operation of the overcurrent protective device. I feel the proposals made to change grounding to bonding will go a long way to eliminate the confusion I see in grounding and bonding.
 

Ed MacLaren

Senior Member
Re: Definition

I agree with Tom.

The non-current carrying metal parts of a system -metal raceways, cable sheaths, cases and frames of equipment - are not grounded by definition.

In fact, each enclosure is bonded (definition - connected) to the next enclosure, and finally to the grounded conductor by way of the main bonding jumper.

Ed

[ March 21, 2003, 05:49 PM: Message edited by: Ed MacLaren ]
 

bennie

Esteemed Member
Re: Definition

Grounding is always bonding, bonding is not always grounding.

Inductor is a conductor with lumped impedance that will resist any change in current.

A bonding jumper is a short conductor to connect two conductive items. Short circuit.

The two are not the same and the engineering community will never permit an equipment ground wire to be called a bonding wire unless it is serving the purpose of bonding.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Definition

Bennie,
I was one of a number of people who submitted the proposals to change EGC to EBC. It is my understanding CMP 5 has accepted this change in principle. This change should be within the scope of CMP 5 and their acceptance will mandate the other panels to make this change.
This conductor is in fact a bonding conductor. Its only purpose is to bond the equipment back to the main bonding jumper a the grounded conductor to provide a fault clearing path. A connection to ground would play no part in clearing a fault. The only way to clear the fault is to cause the current to flow back to the source. The term "EGC" implies that we are trying to make a connection to earth...we are not trying to do that with this conductor. The word "grounding" should only be used for conductors that are connecting the electrical system to the grounding electrode system.
The use of the word grounding leads many to assume that as long as their equipment is connect to earth, it is safe. The changing of this term should make it clear that the function of this conductor is to provide a fault clearing path back to the power source, not to earth.
Don
 

chris white

Member
Location
Pennsylvania
Re: Definition

I think I pretty much agree with what Don is saying here. I've talked to many electricians who assume that grounding a piece of equipment (lighting fixture, motor, receptacle, etc.) to anything nearby serves the same purpose as the EGC back to the main service or other source. For instance, if a connection to the EGC is not too reliable, "at least it's in a metal ceiling grid." or "at least it's bolted to the steel column."

Bennie--how is an EGC an inductor? Because it has impedance? And is that because of the length back to the source? Would you agree that the EGC is meant to be a short circuit, like a bonding conductor?
 

bphgravity

Senior Member
Location
Florida
Re: Definition

But aren't we trying to put all metallic parts to the same potential as ground, which is essentialy zero? I am interested in this change and see the value, but still think there may be just as much confusion. :confused:
 

bennie

Esteemed Member
Re: Definition

Yes, an equipment ground conductor is a bonding conductor.

Grounding does mean to the earth. Every equipment ground wire, I have ever seen, runs from the equipment to the earth.

Every bond wire, I have seen, does not run to earth.

This is apples and oranges being called grapes. :roll:
 

tom baker

First Chief Moderator
Staff member
Re: Definition

Originally posted by bphgravity:
But aren't we trying to put all metallic parts to the same potential as ground, which is essentialy zero? I am interested in this change and see the value, but still think there may be just as much confusion. :confused:
Mike Holts Grounding and Bonding text, 2002 Edition, does an excellent job of explaining this issue. Metallic parts are grounded to limit the voltages imposed by lightning and surges. Metallic parts are bonded to the service grounded(neutral) conductor to provide a low impedance path to facilitate the operation of the overcurrent protective devices. Bonding can be done with out grounding. We spend a lot of time on the grounding when actually the most important part of Art 250 is the bonding. For example, a 20A circuit should have a bonding path to operate clear a fault so it operates in the IT trip region, or 5 to 10 times the setting of 20A.
I support the proposals made by Don and intend to write comments to that effect.
 

tom baker

First Chief Moderator
Staff member
Re: Definition

Originally posted by tom baker:
Originally posted by bphgravity:
But aren't we trying to put all metallic parts to the same potential as ground, which is essentialy zero? I am interested in this change and see the value, but still think there may be just as much confusion. :confused:
Mike Holts Grounding and Bonding text, 2002 Edition, does an excellent job of explaining this issue. Metallic parts are grounded to limit the voltages imposed by lightning and surges. Metallic parts are bonded to the service grounded(neutral) conductor to provide a low impedance path to facilitate the operation of the overcurrent protective devices. Bonding can be done with out grounding. We spend a lot of time on the grounding when actually the most important part of Art 250 is the bonding. For example, a 20A circuit should have a bonding path to clear a fault so it operates in the IT trip region, or 5 to 10 times the setting of 20A.
I support the proposals made by Don and intend to write comments to that effect.
 

bennie

Esteemed Member
Re: Definition

Chris: The equipment ground conductor may or may not be a short circuit.

A bond jumper is always a short circuit.

An equipment ground conductor is intended to carry fault current, plus a zero reference to earth.

A bond conductor may or may not carry fault current. It is not a reference.

To change the present definition will be technically incorrect and grammatically questionable.

[ March 21, 2003, 10:36 PM: Message edited by: bennie ]
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Definition

Bennie,
Every equipment ground wire, I have ever seen, runs from the equipment to the earth.
Not really. An EGC that runs only from the equipment to the earth is a code violation. The very idea that the EGC connects directly to earth is the problem and the main reason for the proposals. The word grounding has long been used to describe this conductor, but it has been used in error by both the industry and the NEC. The EGC runs from the equipment back to the main bonding jumper. At this point it is indirectly connected to earth via the grounding electrode conductor, but that is not the important part of the circuit. The important part is the bonding of the equipment back to the grounded conductor so that there is a low impedance path to clear the fault.
To change the present definition will be technically incorrect and gramatically questionable.
We are not just changing the definition of equipment grounding conductor, we are removing that term completely from the code.

Don
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: Definition

Originally posted by bennie:
The equipment ground conductor may or may not be a short circuit.
That is exactly the reason to change the name, it should always be a short circuit between the MBJ and the loads.

A bond jumper is always a short circuit.
Yes, thats why we should call it a bonding conductor.

An equipment ground conductor is intended to carry fault current, plus a zero reference to earth.
This is only true because that is what we have been calling it.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
Re: Definition

Just for fun, let’s say we have a facility that needs complete isolation from
ground, (earth) yet must utilize conventional 120v (phase to XO forget 647) for the outlets.

We build a platform with non-conductive columns with a 100’ x 100’ deck.
Now we cover the decking of this platform with 1/4" sheet steel.

We serve the area with a delta / wye (120/208) secondary XFMR, we bond XO to the steel with a Bonding Electrode Conductor, (BEC) all the devices are then connected back to the
Bonded Conductor (BC) in the panel through the white conductor we install for this purpose.

All conductive components are then bonded through an Equipment Bonding Conductor (EBC) back to the BEC at the XO point and we have, or strive for equal potential between these.

Now we are talking bonding exclusively.

My question is, shouldn’t we change the term Grounded Conductor , or in this example, Bonded Conductor to Return Conductor :D

Roger

[ March 21, 2003, 11:03 PM: Message edited by: roger ]
 

bennie

Esteemed Member
Re: Definition

Hello Roger: I have researched this issue. The main reason for confusion is the NEC is trying to coin new words in the English language.

Grounded and grounding are not proper or accepted words in the Websters dictionary. :mad:
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
Re: Definition

Hello back Bennie, I hope you get feeling better so you can make your trip to Kwajalien. (or did you go already?)

You're right about grounded and grounding, my spell check pegs these everytime. :roll:

Roger
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Definition

Bennie,
Grounded and grounding are not proper or accepted words in the Websters dictionary.
That is why these and other words appear in Article 100.

Roger,
It still would be called a grounding electrode conductor. See Article 100-grounded. Also with very few exceptions, a 120 volt ungrounded system is a code violation. How could we call it a "return conductor" in an AC system? Current flows both directions in all conductors.
Don
Don
 

bennie

Esteemed Member
Re: Definition

Roger: The NEC does not have the authority to change the English language.

I know I seem negative towards the NEC. I don't intend to be that way. I am concerned about some of the interpretations that are creating unsafe and inferior conditions.

I am out of it now, but will always have an interest in proper technology application.

I am still planning to make the trip. My health is precarious, and untreatable. I am not expected to last much longer. I want to do this but may not be able.
 

Ed MacLaren

Senior Member
Re: Definition

The NEC does not have the authority to change the English language.
Languages evolve. If they didn’t, we might all be speaking like this –

"Who so shall telle a tale after a man,
He moste reherse, as neighe as ever he can,
Everich word, if it be in his charge,
All speke he never so rudely and so large;
Or elles he moste tellen his tale untrewe,
Or feinen thinges, or finden wordes newe."

Canterbury Tales. Prologue. Line 733.


Electrical codes, by their nature, are technical documents, which often require new terms, as the technology evolves.

Ed

[ March 22, 2003, 08:44 AM: Message edited by: Ed MacLaren ]
 
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