Offset Nipple between Meter and Disco

[e57]

Mark, is it that you refuse to believe what is written in the NEC or that you just do not agree with it?

Because it is very clear that a service raceway only has to be bonded to the neutral once. Nothing you have said ......... and God knows you have said a lot...... :grin: has shown that not to be true.

No matter how you like to do it or how you are used to seeing it done changes the basic NEC requirement of one bond required per raceway. It almost seems like you are trolling here.

I think its clear I dont agree with it. I believe the code as written is flawed, and ignores the other path that is not aknowledged in the code section 250.92(B) specifically. By pointing to only 250.92(B)1 alone - by itself ignores the requirements stated in 250.92(A), and 250.90 and the words by thier definition in them. Again IMO the code is flawed in that way.

Am I 'trolling', or baiting anyone into conflict by stating that opinion. On or with purpose of doing that - no I am not. Have I ruffeled a feather or two in the process - it would seem so. You may feel free to close the thread if you do not believe me on that - in fact I have used the "report at thread' link to do just that and even asked if George can have the last word.

But has it changed my mind - no. You and I have agreed to dis-agree in the past, and I am not above doing the same with anyone else.

 

[wwhitney]

As a definition of "bonded", this NEC definition leaves a lot to be desired. It is really only a definition of "bonding". The definition of "bonded" based on this is "having bonding to the common reference point", which would be the GEC or thereabouts.

I have no idea where you get that? How would you apply that to an ungrounded system? "Bonding" still applies in that case - does it not?

Sure, bonding still applies to an ungrounded system. My understanding is that in such a system the non-current carrying metal parts are still all bonded together and still bonded to a grounding electrode system so as to be at earth potential. That's why I suggested the GEC is the common reference point. But perhaps my understanding is mistaken.

Cheers, Wayne

 

[e57]

Sure, bonding still applies to an ungrounded system. My understanding is that in such a system the non-current carrying metal parts are still all bonded together and still bonded to a grounding electrode system so as to be at earth potential. That's why I suggested the GEC is the common reference point. But perhaps my understanding is mistaken.

Cheers, Wayne

In a multiple enclosure ungrounded system example what are the methods of bonding each enclosure to the GEC? I wont try to offer an opinion on the matter. Answer that for yourself.

 

[wwhitney]

In a multiple enclosure ungrounded system example what are the methods of bonding each enclosure to the GEC? I wont try to offer an opinion on the matter. Answer that for yourself.

Sure: everything still needs at least one low impedance fault path. So if you want to use a metallic nipple as part of a low impedance fault path, then certainly you would need bonding on both ends. Alternatively, you could use an equipment bonding jumper between enclosures, and then you only need bonding on one end of the nipple.

And in the case of a grounded service, you can use the grounded service conductor in place of the equipment bonding jumper. So if the grounded service conductor is bonded to both enclosures, you only need bonding on one end of the nipple.

Here's a related question. Bonding bushings (or the like) are required under certain conditions after the service disconnect. Suppose a metallic nipple meets those conditions at both ends, and that nothing on either side of the nipple depends on the nipple itself to be part of the required low impedance fault path. Do you feel that such a nipple requires bonding bushings on both ends?

Cheers, Wayne

 

[e57]

Sure: everything still needs at least one low impedance fault path. So if you want to use a metallic nipple as part of a low impedance fault path, then certainly you would need bonding on both ends. Alternatively, you could use an equipment bonding jumper between enclosures, and then you only need bonding on one end of the nipple. (1)

And in the case of a grounded service, you can use the grounded service conductor in place of the equipment bonding jumper. So if the grounded service conductor is bonded to both enclosures, you only need bonding on one end of the nipple. (2)

Here's a related question. Bonding bushings (or the like) are required under certain conditions after the service disconnect. Suppose a metallic nipple meets those conditions at both ends, and that nothing on either side of the nipple depends on the nipple itself to be part of the required low impedance fault path. Do you feel that such a nipple requires bonding bushings on both ends? (3)

Cheers, Wayne

1. As mentioned (alot) IMO if you have two or more paths - one being the low impedance neutral (a normally current carrying conductor) - IMO the other high impedance one(s) should at least meet 250.66 with a bonding jumper or other listed means to provide the equivenent. On the service side of the disconnecting means... Without quanifying the minimum that connection could be anything.... (this is sure to raise some irk - but not intended for that purpose) For that matter - does the other side (high impedance side) even need to be considered grounded? Does it need to even have locknuts at all apart being held in place? It is grounded on one side.
2. See comments above.
3. Not sure I quite follow you - or can think of a situation fitting that - could you elaborate more or provide an example? Is it part of the current path requiring to be low impedance.

 

[George Stolz]

Quit acting stupid.

Look George, It is obvious that we (you and I) are not going to agree. But please knock of the 'stupid' type comments - they only serve to belittle yourself. Really whats next 'momma jokes'?

I apologize for the disrespect. What I meant to say, and then vein I meant it in, is "Quit act--" did it again, no joke-- "Quit playing stupid."

In a discussion, especially one of this length, pulling something someone has said out of context and twisting it is just a tactic to confuse and prolong a conversation. Is it really necessary at Post 135? I am making every attempt at understanding what you write, every post, because I know you're an intelligent man and up until this conversation ( ) I thought you made sense for the most part.

The only reason that I still participate right now, is because I hold some hope that your intelligence and reason will overcome your will on this issue.

You know damned well I was referring to the fact that the raceway is also bonded by the locknuts securing that raceway to the can.

"Standard locknuts or bushings shall not be the sole means for the bonding required by this section." The connection on one side has a bushing and jumper, the other side does not.

Jeez o Petes - it flat out says "shall not be the sole means" - which tells me that the writers were well aware that the locknuts perform a bonding function.

This is where I point to when I say that you are attempting to confuse the issue. Use proper terms. I'll let you call it "connected" when you want to communicate that you don't trust the bonding connection, but flopping over to "grounding" is useless.

Not flopping - anything... one side is grounded by definition, the other is bonded by definition. As a fault current path - it is not fitting the definition of "bonded".

This part of the discussion is pointless distraction, I say we drop it.

Your issue is not the presence of two paths, so why keep harping on it? You're just confusing your case.

My issue IS the two paths, ALWAYS has been from the very beginning. One fits the definition of bonded, the other does not. (IMO it is '1/2 bonded', you and many others will say it is 'ALL bonded' - 'just a little bonded = BONDED'....)

Dude, they are one and the same. There is only one nipple. It is bonded.

Only you have disconnected it from it's meaning.

It's 'meaning' is there in black and white. IMO it's meaning has become a 'description', a 'label'. One word - removed from its definition.So you don't have to look it up....

Now ask yourself. Without the neutral, is the metallic conduit path "Bonded"?

Because with, or without the neutral - it needs to fit the definition IMO. It is still 'an electrically conductive path that needs to ensure electrical continuity and the capacity to conduct safely any current likely to be imposed.'

Without the neutral, they're going to have a heck of a time blowing up dishwashers, light bulbs, I don't think there's much of a chance they're going to take it with them when they move out.

You're just not making any sense.

 

[George Stolz]

Am I 'trolling', or baiting anyone into conflict by stating that opinion. On or with purpose of doing that - no I am not. Have I ruffeled a feather or two in the process - it would seem so. You may feel free to close the thread if you do not believe me on that - in fact I have used the "report at thread' link to do just that and even asked if George can have the last word.

That was an odd email, to say the least. I'd say it's the first time a participant in a conversation has demanded that their opponent get the last word in before a lock.

I chalked it up as another bizarre diversion, ala "good enough for grounding but not bonding."

 

[DesignElectric]

Ahj

Ahj

1st; Perhaps he was ingnorant in as far as a parallell bond?
2nd; Was the E > 250V?
Design

 

[e57]

That was an odd email, to say the least. I'd say it's the first time a participant in a conversation has demanded that their opponent get the last word in before a lock.

I chalked it up as another bizarre diversion, ala "good enough for grounding but not bonding."

Was that your last word? Or should I address the previous post?

 

[wwhitney]

On the service side of the disconnecting means... Without quantifying the minimum that connection could be anything.... (this is sure to raise some irk - but not intended for that purpose) For that matter - does the other side (high impedance side) even need to be considered grounded? Does it need to even have locknuts at all apart being held in place?

To the last question, no, the locknuts are not there to serve any bonding purpose. They are there for the mechanical execution of the work. You could use a non-conductive locknut (if such locknuts exist and can be used with RMC).

BTW, you once asked for an insulated termination for RMC. If there are insulated reducing washers and insulated locknuts, you could make an insulated termination using an oversized knockout. Again, I have no idea if such products exist.

Not sure I quite follow you - or can think of a situation fitting that - could you elaborate more or provide an example? Is it part of the current path requiring to be low impedance.

If I understand 250.97 correctly, then for a circuit over 250V, when a conduit enters a concentric knockout, then standard locknuts are not adequate for bonding. So if you have two 480/277V panels with a nipple between them with concentric knockouts at both ends, you need to provide additional bonding at one end, like a bonding bushing. If the nipple is to provide the EGC connection between the panels, you need additional bonding at both ends, certainly. But if there is a wire EGC in the nipple, do you feel that additional bonding should still be required at both ends?

Cheers, Wayne

 

[lakee911]

If I understand 250.97 correctly, then for a circuit over 250V, when a conduit enters a concentric knockout, then standard locknuts are not adequate for bonding. So if you have two 480/277V panels with a nipple between them with concentric knockouts at both ends, you need to provide additional bonding at one end, like a bonding bushing. If the nipple is to provide the EGC connection between the panels, you need additional bonding at both ends, certainly.

Also applies to eccentric knockouts, and the 470/277V condition you list above applies to services (even if less than 250V).

But if there is a wire EGC in the nipple, do you feel that additional bonding should still be required at both ends?

I think this is where the debate starts ...

 

[e57]

Not trying to start in to any long drawn out stuff - as - it's pretty dran out already.... I'll PM you.... So as not to offend.

 

[iwire]

So how about those Bruins?

 

[flashlight]

Thanks, everyone for all your comments. It prompted a deeper reading of
article 250 for me, to say the least. :roll:

We had follow-up inspection, had installed jumper as inspector requested. I had planned to ask guy for his exact code citations, but it was a junior guy subbing for original inspector working off his notes, so I just shut up and passed.

 

[augie47]

Thanks, everyone for all your comments. It prompted a deeper reading of
article 250 for me, to say the least. :roll:

We had follow-up inspection, had installed jumper as inspector requested. I had planned to ask guy for his exact code citations, but it was a junior guy subbing for original inspector working off his notes, so I just shut up and passed.

probably the best route, but I think I would have asked him "why" just to make him think. Would have been eduational to him.

 

[George Stolz]

...so I just shut up and passed.

Which is ironic on two counts: the path this thread took, and the fact that I would probably have done the same.

 

[wwhitney]

Not sure I quite follow you - or can think of a situation fitting that - could you elaborate more or provide an example?

OK, I guess I still wasn't clear, let me try one more time.

There are two places (I'm aware of) that Article 250 requires bonding for RMC beyond a pair of locknuts at an enclosure. One is before the main disconnect, the other is anywhere the voltage to ground is over 250V and the RMC is entering concentric, eccentric, or oversized knockouts.

Now for a nipple in either case, everyone agrees that if the nipple is to be part of the required low impedance fault path, then this additional bonding applies at both ends. Your main point as I understand it is that you feel that for a nipple before the main disconnect, even if it is not part of the required low impedance fault path [because enclosures on both sides are bonded to the neutral], the additional bonding should still be required at both ends.

So how about the other case, after the main disconnect but over 250V and concentric, eccentric, or oversized knockouts at each end of the nipple? If the nipple is not part of the required low impedance fault path, because an EGC is installed in the nipple and bonded to both enclosures, do you feel that the nipple ought to still have the additional bonding at both ends? If not, what is it about the difference in the two situations that accounts for the difference in your proposed requirements?

Thanks,
Wayne

 

[flashlight]

probably the best route, but I think I would have asked him "why" just to make him think. Would have been eduational to him.

Honestly, I should have. But we were under heavy pressure to sign this one off so a business could open and I just didn't want to stir anything up. Cluck, cluck.

 

[stafelectric@yahoo.com]

What did you do to make this guy mad? Never in my life would i think that would play,with it megged.

 

[cpopinc]

You need a bonding jumper inside the meter enclosure or the mail gear, Not both places as you will be paralleling the neutral current.