Egc vs. Ebj

[gamit69]

What is the difference between a equipment grounding conductor and a equipment bonding jumper? Don't they both serve the same purpose? They are sized according to OCP and are run on the load side of the service,right. Would there ever be a case where both would be used in the same service?

The NEC sometimes makes me crazy!!

 

[Volta]

Almost the same.

The EGC can be thought of as the normal conductor for bonding equipment frames or raceways, in general, to the Grounding Electrode Conductor and the Grounded Conductor.

The EBJ can be thought of as the small jumpers needed to complete the path(s) for the EGC. Like a green wire bonding a receptacle grounding terminal to a box. It is an EGC, but can more specically be called the jumper.

As you said, they are used on the load side of the service disconnect, so they aren't used for the service per se.

Think of the EGC being connected to the Grounded Conductor via a Main Bonding Jumper there.

 

[gamit69]

Almost the same.

The EGC can be thought of as the normal conductor for bonding equipment frames or raceways, in general, to the Grounding Electrode Conductor and the Grounded Conductor.

The EBJ can be thought of as the small jumpers needed to complete the path(s) for the EGC. Like a green wire bonding a receptacle grounding terminal to a box. It is an EGC, but can more specically be called the jumper.

As you said, they are used on the load side of the service disconnect, so they aren't used for the service per se.

Think of the EGC being connected to the Grounded Conductor via a Main Bonding Jumper there.

Why have both...Just call it one or the other and be done with it! Thanks

 

[Smart $]

Why have both...Just call it one or the other and be done with it! Thanks

I disagree with with Volta's comments.

Though we refer to one as an EGC, it is more accurately described as an electrical equipment grounding conductor and is run with feeders and branch circuits to the connected electrical equipment. EGC's are always on the load side of the system disconnecting means.

An EBJ is a grounding conductor used in instances where bonding of non-current-carrying metal parts is required, necessary, or simply desired, and not provided for by either EGC(s) or the grounding electrode system (GES). Grounding conductors on the line side of the system disconnecting means are of this type in many instances, but these can also be used to bond non-current-carrying metal parts anywhere. For example, from a grounding ring or grid to a piece of machinery or an otherwise isolated section of metal floor decking.

 

[yired29]

250.102 covers equipment bonding jumpers line and load side. Remember we use line side bonding jumpers on separately derived systems 250.30 A 2

 

[Volta]

I disagree with with Volta's comments.

Though we refer to one as an EGC, it is more accurately described as an electrical equipment grounding conductor and is run with feeders and branch circuits to the connected electrical equipment. EGC's are always on the load side of the system disconnecting means.

An EBJ is a grounding conductor used in instances where bonding of non-current-carrying metal parts is required, necessary, or simply desired, and not provided for by either EGC(s) or the grounding electrode system (GES). Grounding conductors on the line side of the system disconnecting means are of this type in many instances, but these can also be used to bond non-current-carrying metal parts anywhere. For example, from a grounding ring or grid to a piece of machinery or an otherwise isolated section of metal floor decking.

You are right to say that an EBJ is more than "small jumpers needed to complete the path(s) for the EGC".

That was an incomplete statement, and while not fully incorrect, misleading. It is used for that purpose (250.146), but as you point out, on the supply side (250.102) also.

 

[bphgravity]

By definition, an equipment grounding conductor is the conductive path installed to connect normally non-current-carrying metal parts of equipment together to the system grounded conductor or to the grounding electrode conductor, or both.

The equipment bonding jumper is the connection between two or more portions of the equipment grounding conductor.

Nothing more.

 

[Smart $]

By definition, an equipment grounding conductor is the conductive path installed to connect normally non-current-carrying metal parts of equipment together to the system grounded conductor or to the grounding electrode conductor, or both.

The equipment bonding jumper is the connection between two or more portions of the equipment grounding conductor.

Nothing more.

Yeh... but those definitions could stand some clarification. Specific requirements of each in the Code contradict the basic defintions.

For example, you will find many instances of EBJ's that do not connect two or more portions of the equipment grounding conductor.

Another is EGC's are required to be run with feeder and circuit conductors and are only required to be connected to the equipment served. Thus, you will not have any EGC's which bond non-current-carrying metal parts of non-electrical equipment.

Also, those defintions lead to the confusion many have on which is which.

 

[K8MHZ]

So...

Jumper = terminated at both ends

Conductor = terminated only at one end until a fault occurs?

I guess I only considered the jumper to be the connection between the grounding and the grounded conductor in the service (or other SDS).

No code book here to look it up, sorry. I ended up in the hospital yesterday and they likley won't release me until tommorrow.

I have found several code violations here though! I am thinking the more I find the faster they will want to get rid of me!

 

[bphgravity]

For example, you will find many instances of EBJ's that do not connect two or more portions of the equipment grounding conductor.

That can't be. If it's not conneting two or more portions of the EGC, then it's something else and not an EBJ. Please example these many instances you claim.

Another is EGC's are required to be run with feeder and circuit conductors and are only required to be connected to the equipment served. Thus, you will not have any EGC's which bond non-current-carrying metal parts of non-electrical equipment.

I don't follow. In the first sentence you state state EGC's are required, then in the second sentence you state you will not have an EGC? Please clarify and example when an EGC is installed that doesn't meet definition.

 

[Smart $]

That can't be. If it's not conneting two or more portions of the EGC, then it's something else and not an EBJ. Please example these many instances you claim.

The most common is equipment bonding on the line side of a service. There are no EGC's on the line side of the service-MBJ-GES bond point. So any grounding conductor on the line side of that point is an EBJ and not connecting two portions of EGC's.

PS: Don't expect this to get any less confusing in the upcoming cycle of the NEC

I don't follow. In the first sentence you state state EGC's are required, then in the second sentence you state you will not have an EGC? Please clarify and example when an EGC is installed that doesn't meet definition.

I see you are confused yourself...

Say you have a non-electrical-powered machine, mostly metallic in design, sitting in the middle of a concrete industrial-space floor. It is powered by hydraulic and pneumatic non-conductive lines. This machine is quite large and has an operation and service cat walk with several flights built all around it. At this point, with no electrical power run to these structures, there is no connected EGC and all the metal is ungrounded. How are these to be grounded?

 

[Volta]

...
Say you have a non-electrical-powered machine, mostly metallic in design, sitting in the middle of a concrete industrial-space floor. It is powered by hydraulic and pneumatic non-conductive lines. This machine is quite large and has an operation and service cat walk with several flights built all around it. At this point, with no electrical power run to these structures, there is no connected EGC and all the metal is ungrounded. How are these to be grounded?

Well, assuming the machine does not fall under 250.116, we won't need NEC definitions for it, but probably could still use them. Let's call the cat walk flights a 'building frame' for 250.104(C), ignore the "intentionally grounded" conundrum 250.104(C), and say it is likely to become energized.

Then we must bond the structural metal to either the:

• service enclosure,
• grounded service conductor, or
• GEC

We will size our conductor to 250.66 (based on the size of the conductor likely to energize this 'building frame', subject to interpretation).

We will call it a "bonding jumper". It does not need the prefix "equipment", as a 'building frome' is generally not considered equipment.

If we wanted to connect the various components of this non-electrical machine, we could probably rightly call those conductors "equipment bonding jumpers". We can run one to the preceeding list of options using the same name. I don't think NFPA 79 refers to non-electrical equipment, so not likely required by any standard (if non-hazardous materials, anyway).

 

[bphgravity]

The most common is equipment bonding on the line side of a service. There are no EGC's on the line side of the service-MBJ-GES bond point. So any grounding conductor on the line side of that point is an EBJ and not connecting two portions of EGC's.

Wrong. All the normally non-current-carrying metal parts of equipment (LINE or LOAD side of the service disconnect) must have a conductive path to the grounded conductor, GEC, or both. This conductive path, by definition, is the equipment grounding conductor. If you install a jumper between any two of these parts, or from any of these parts to the grounded terminal bar, EGC, GEC, or enclosure of the service, it is an equipment bonding jumper.

I see you are confused yourself...

I am only confused about your statements, not with the code.

Say you have a non-electrical-powered machine, mostly metallic in design, sitting in the middle of a concrete industrial-space floor. It is powered by hydraulic and pneumatic non-conductive lines. This machine is quite large and has an operation and service cat walk with several flights built all around it. At this point, with no electrical power run to these structures, there is no connected EGC and all the metal is ungrounded. How are these to be grounded?

There is no requirement to provide an effective fault path on non-electrical metal parts and equipment of a building or structure that is not likely to become energized. So, if you have non-electrical equipment, it is not required to be connected to an EGC. That doesn't change the definition or purpose of an EGC. Now, if that equipment is likely to become energized, it may need to be bonded to the electrical system. Actual grounding of the equipment would be acccomplished with the use of auxiliary electrodes, which is also not required but permitted.

The definitions, in fact, are accurate and need no clarification.

 

[don_resqcapt19]

This is always a confusing issue because of the terminology used in the NEC. CMP 5 should have accepted the proposal for the 2005 code that would have changed this. The term grounding should be used only for a conductor that has a direct connection to the grounding electrode. All other conductors that are now called "grounding" should be called "bonding" because that is exactly what they do...they bond things to the grounded or grounding conductor as required.
The Canadian Electrical code changed their rules a number of years ago and, in talking with instructors, they have found the level of confusion for new students has been reduced.

 

[bphgravity]

I completely agree. At least they changed the phrase, "must be grounded" to "connected to an equipment grounding conductor". Plus, the FPN to the EGC definition clarifies the purpose is actually bonding.

 

[Smart $]

Wrong. All the normally non-current-carrying metal parts of equipment (LINE or LOAD side of the service disconnect) must have a conductive path to the grounded conductor, GEC, or both. This conductive path, by definition, is the equipment grounding conductor. If you install a jumper between any two of these parts, or from any of these parts to the grounded terminal bar, EGC, GEC, or enclosure of the service, it is an equipment bonding jumper.



I am only confused about your statements, not with the code.

I have to disagree, respectfully. Here's the simple argument to your comment. Anything grounded per Article 250 Part V Bonding uses Equipment Bonding Jumpers. Another example of an EBJ not connecting portions of EGC's is the bonding of metal piping systems and exposed structural steel as also covered under Part V Bonding, 250.104.


Grounding of normally non-current-carrying metal parts of service equipment is covered in Part V Bonding, not in Part VI Equipment Grounding and Equipment Grounding Conductors. Additionally, you will find no mention of service, service equipment, or the such in Part VI. Yes, there is mention in Part VII Methods of Equipment Grounding... but since it's not covered in Part VI, it just adds to the confusion.

There is no requirement to provide an effective fault path on non-electrical metal parts and equipment of a building or structure that is not likely to become energized. So, if you have non-electrical equipment, it is not required to be connected to an EGC. That doesn't change the definition or purpose of an EGC. Now, if that equipment is likely to become energized, it may need to be bonded to the electrical system. Actual grounding of the equipment would be acccomplished with the use of auxiliary electrodes, which is also not required but permitted.

Grounding of the machine and cat walk, as simplistically stated, is not required. Yet as you so noted if either is likely to become energized, the cat walk would be required to be "bonded" under 250.104 (as in EBJ not connecting portions of EGC's ), while the machine would be grounded with an EGC. There are several ways to accomplish both, but I'll not get into that... unless someone feels it necessary.

The definitions, in fact, are accurate and need no clarification.

I've already stated my position and stand by it. Yet with all that said, I wish the ambiguity was removed by classifying both as simply Grounding Conductors (GC's), and then subcategorize as perhaps line side, load side, or something similar, so as to size appropriately. Also, it stands to reason if a conductor connects two or more portions of GC's, it is thence a GC...???... not this EBJ/EGC bull crap

EDIT: Just read Don's post (it wasn't there when I started my reply). I'd be happy with "BC"

 

[Smart $]

Well, assuming the machine ...

Don't mean to avoid you but had to pull one of those got to have it done by morning all nighters and a bit exhausted. Hopefully my response to Bryan will suffice. If not, let me know...

 

[bphgravity]

Anything grounded per Article 250 Part V Bonding uses Equipment Bonding Jumpers. Another example of an EBJ not connecting portions of EGC's is the bonding of metal piping systems and exposed structural steel as also covered under Part V Bonding, 250.104.

Wrong again. Bonding in accordance with Part V of Article 250 can be accomplished using bonding jumpers and equipment bonding jumpers. EBJ's are not required for 250.104 bonding, bonding jumpers are.

Grounding of normally non-current-carrying metal parts of service equipment is covered in Part V Bonding, not in Part VI Equipment Grounding and Equipment Grounding Conductors. Additionally, you will find no mention of service, service equipment, or the such in Part VI. Yes, there is mention in Part VII Methods of Equipment Grounding... but since it's not covered in Part VI, it just adds to the confusion.

These statements don't change anything and there shouldn't be any confusion. Bonding is performed under Part V, not grounding. All the metal parts of the electrical premise wiring must have an effective fault path back to the source. Per definition, all the metal equipment of the system is connected back to the service via the EGC. Jumpers installed between portions of these EGC's are EBJ's.

Other conductors installed for the purposes of bonding are just jumpers.

 

[Smart $]

Wrong again. Bonding in accordance with Part V of Article 250 can be accomplished using bonding jumpers and equipment bonding jumpers. EBJ's are not required for 250.104 bonding, bonding jumpers are.




These statements don't change anything and there shouldn't be any confusion. Bonding is performed under Part V, not grounding. All the metal parts of the electrical premise wiring must have an effective fault path back to the source. Per definition, all the metal equipment of the system is connected back to the service via the EGC. Jumpers installed between portions of these EGC's are EBJ's.

Other conductors installed for the purposes of bonding are just jumpers.

I'll not debate the issue anymore, as I've already made my point and to rehash it over semantics would be utter nonsense.

 

[bphgravity]

I don't believe the discussion is over semantics but rather how the code defines terms and when those terms are used in the code. The understanding of the definitions is perhaps the most critical aspect for the proper interpretation of the code. The location of a comma in a sentence can change the entire meaning of a section, so just imagine how the difference a single word or term can make.