Equipment grounding bonding jumper conductor question?

Status
Not open for further replies.
ritelec

ritelec

Senior Member
Location
Jersey
I'm understanding but not the egc, ebj the ssbj the lsbj.

From what I understand, even though we ground equipment and receptacles etc., we are actually bonding them.
Grounding would be earthing right?

But even if we did call it grounding, the egc definition is "the conductive path that connect metal parts of equipment to the system neutral conductor, to the grounding electrode conductor, or both."

So even though these bonding jumpers and conductors are actually bonding jumpers and conductors, they should eventually or immediately connect a conductive path to the neutral or electrode conductor or both so shouldn't they be a egc?

I was reading and saw 2- MH's cartoon pics, for 250.102 (D) which shows equipment bonding jumpers (one is a picture of 3- bonding (or egc) entering 3 pipes and labeled "bonding jumpers" and one is one bonding jumper attached to 3- pipes via grounding bushings).

I enclosed a MH cartoon, not the one I see in a book that I'm referring to but something similar.

Not life threatening, just wondering.

Thank you.
 
The three bonding jumpers that are in the graphic in your post are connected to the raceway, probably with a bonding bushing out of view, they are not within the raceways.
 
infinity said:
The three bonding jumpers that are in the graphic in your post are connected to the raceway, probably with a bonding bushing out of view, they are not within the raceways.
Click to expand...

ok. and a tree that falls in the woods makes a sound.







Totally playing, thank you.

I did take these ole eyeballs and looked at the book pics again. It does appear as if they stop at the pipe and don't enter it.

Thanks
 
When you ground recep and equp you are bonding them.....to the ground wire. You are bonding the chassis, the boxes, the conduit. You are trying to equalize the potential on touchable objects so people don't get poked. You are also trying to ensure that if there is a problem in the wiring or a device that the chassis or raceway cannot become energized.

With the raceways and chassis of equip being bonded the breaker should trip.

Bonding the neutral at the main service disconnect doesn't turn every raceway into a neutral. But bonding raceways, building steel and equipment is equalizing the potential throughout the building and hopefully supplying a foolproof path for faults to trip as soon as they happen.

Bonding is different than bonding. Grounding is a odd word as well. Maybe it could be worded differently.

Grounding to the earth to earth doesn't actually supply a ground. Imagine driving a ground rod at each device instead of pulling wire. It would be silly, plus it wouldn't work.
Watch the grounding video on this site, heck I may watch it again myself to find out how bad I botched this.:)
 
Last edited:
J.P. said:
When you ground recep and equp you are bonding them.....to the ground wire. You are bonding the chassis, the boxes, the conduit. You are trying to equalize the potential on touchable objects so people don't get poked. You are also trying to ensure that if there is a problem in the wiring or a device that the chassis or raceway cannot become energized.

With the raceways and chassis of equip being bonded the breaker should trip.

Bonding the neutral at the main service disconnect doesn't turn every raceway into a neutral. But bonding raceways, building steel and equipment is equalizing the potential throughout the building and hopefully supplying a foolproof path for faults to trip as soon as they happen.

Bonding is different than bonding. Grounding is a odd word as well. Maybe it could be worded differently.

Grounding to the earth to earth doesn't actually supply a ground. Imagine driving a ground rod at each device instead of pulling wire. It would be silly, plus it wouldn't work.
Watch the grounding video on this site, heck I may watch it again myself to find out how bad I botched this.:)
Click to expand...

I think you're right, (in red above) it could be worded differently.....Bonding is different than bonding...:?:)

As far as what you said about trying to keep things at the same potential, that is not why metal objects need to be bonded. That may happen in the process, but the reason is to provide a low resistance path back to the source so the breaker will trip during a fault.

Now a bonding grid is to keep everything at the same potential, such as around/in a pool or agricultural building.
 
IMO 250 still needs lots of work. IMO fault clearing systems, and system and equipment earthing have no business being in the same article even though they often use the same conductor for parts of each of the systems. I think of it this way: 1) stuff needs a fault path back the source (the important one) 2) stuff needs to be connected to the earth (the not so important one). Theoretically, this means everything IS bonded together, however that is not actually the case as we have different systems that need to be tied together (such as connecting the egc to the neutral so a fault can get back to the source) and certain connections that we dont trust (i.e. some conduit to box connections on certain systems), so we use bonding jumpers. A bonding jumper could be completing/improving the path to earth or the fault path or both.
 
electrofelon said:
IMO 250 still needs lots of work. IMO fault clearing systems, and system and equipment earthing have no business being in the same article even though they often use the same conductor for parts of each of the systems. I think of it this way: 1) stuff needs a fault path back the source (the important one) 2) stuff needs to be connected to the earth (the not so important one). Theoretically, this means everything IS bonded together, however that is not actually the case as we have different systems that need to be tied together (such as connecting the egc to the neutral so a fault can get back to the source) and certain connections that we dont trust (i.e. some conduit to box connections on certain systems), so we use bonding jumpers. A bonding jumper could be completing/improving the path to earth or the fault path or both.
Click to expand...
Though I agree some things could maybe use some tweaking I don't agree that fault clearing and earthing need further separation in the organization of 250. They already are in separate subsections of 250. Part II is system grounding, Part III is the grounding electrode system, part V is bonding, part VI is equipment grounding conductors.

The main key is to understand the difference between a few key terms: Grounded conductor, (equipment) grounding conductor, grounding electrode conductor, ground, grounded, grounding, bond, bonded, bonding, neutral, are a few terms to start with.

The biggest confusion I think comes from having that same root word (ground) in most of those terms, they begin to all mean the same thing to many just because of the root. Something tells me that changing the terms may clear a few things up for some people but will still leave about as much confusion for others.
 
ritelec said:
But even if we did call it grounding, the egc definition is "the conductive path that connect metal parts of equipment to the system neutral conductor, to the grounding electrode conductor, or both."
Click to expand...
This is one area of confusion - use of the word "neutral". Though what you said is correct nearly all the time, there are systems that don't have a "neutral" conductor but still have a "grounded conductor" But a system that has a neutral conductor usually is required to have that neutral be the conductor that is grounded.

If we did not have corner grounded systems, or any other system that had something other then a "neutral" as the grounded conductor or even ungrounded systems, that would also help clarify things for some people - especially those that never run into those things. An ungrounded system still has a grounding electrode system, equipment grounding conductors and all the bonding jumpers that a grounded system has.
 
Is there anything in Article 100 that makes a distinction between a grounded conductor and a neutral? The way I read it according to the definitions they're one in the same.
 
infinity said:
Is there anything in Article 100 that makes a distinction between a grounded conductor and a neutral? The way I read it according to the definitions they're one in the same.
Click to expand...
They are often the same thing, but not always the same thing.

Even the definitions do not mention the other term or any form of the same word.

A grounded conductor of a corner grounded delta system does not fit the definition of a neutral conductor.
A grounded conductor of a two wire source does not fit the definition of a neutral conductor.

It is more rare to find an application where there is a neutral that is not also grounded - but mostly because other NEC sections generally require that system conductor to be the one that is grounded.

[h=5]Grounded Conductor.[/h]A system or circuit conductor that is intentionally grounded.


[h=5]Neutral Conductor.[/h]The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.
[h=5]Neutral Point.[/h]The common point on a wye-connection in a polyphase system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct-current system.
Informational Note: At the neutral point of the system, the vectorial sum of the nominal voltages from all other phases within the system that utilize the neutral, with respect to the neutral point, is zero potential.



​
 
kwired said:
They are often the same thing, but not always the same thing.

Even the definitions do not mention the other term or any form of the same word.

A grounded conductor of a corner grounded delta system does not fit the definition of a neutral conductor.
A grounded conductor of a two wire source does not fit the definition of a neutral conductor.

It is more rare to find an application where there is a neutral that is not also grounded - but mostly because other NEC sections generally require that system conductor to be the one that is grounded.

Grounded Conductor.

A system or circuit conductor that is intentionally grounded.


Neutral Conductor.

The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.
Neutral Point.

The common point on a wye-connection in a polyphase system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct-current system.
Informational Note: At the neutral point of the system, the vectorial sum of the nominal voltages from all other phases within the system that utilize the neutral, with respect to the neutral point, is zero potential.



​
Click to expand...

Thanks, I forgot about the two "other" instances that you've mentioned that aren't in the neutral point definition. It's interesting that the neutral point definition eliminates the argument that a two wire circuit from any of those system mentioned could contain a neutral and not a grounded conductor.
 
Status
Not open for further replies.
Top