Inspector correct or not????

[chevyx92]

One futher point. The PVC service conduits being 30 feet long makes me wonder if there isn't a violation of 230.70(A)(1). How far is the service disconnect from the point of entrance of the service conductors?

There is no issue with 230.70(A)(1). The 30ft of pipe is outside and then enters right into back of panelboard.

 

[chevyx92]

One last time: If a wire is in a raceway, then how can the rules for being outside a raceway apply?
RED TAG!!

If it's not IN a raceway then it's OUTSIDE of the raceway.

 

[Smart $]

Darn. Okay, y'all have me there. 250.102(E) does say what y'all are saying it says.

Okay, this is all pretty distasteful to me. Surely that can't be a legal means of bonding between the CT/trough and the service disconnect 30 feet away.

Here we go - time for me to throw this back on y'all. :wink: think carefully, this may be hard to follow.

300.3(B) gives the "in general" statement that all the associated conductors including the bonding jumper be installed in the same raceway except as permitted in (B)(1) through (B)(4).

(B)(2) says that the bonding jumper can be installed >>on the OUTSIDE of raceways<< in accordance with 250.102(E).

Now.... is that equipment bonding jumper on the outside of a raceway?

No. It is installed inside of a raceway. Therefore (B)(2) does not apply. (B)(2) is for OUTSIDE of raceways.

What we have here is 3 PVC conduits installed in parallel between the trough and the disconnect.

2 of those conduits contain phase and grounded conductors. The third contains only a bonding jumper. Therefore 300.3(B) is violated.

Do you see the logic there?

Now, if the bonding jumper was on the outside of a racewya and less than 6 feet, so be it. Putting it in a conduit negates the freedom to put it on the outside of a conduit.

One last time: If a wire is in a raceway, then how can the rules for being outside a raceway apply?

RED TAG!!

Your logic is oh so close to being impeccable...

However, the only "raceways" that 300.3(B)(2) can be referring to are those in the general requirement. Hence an EBJ not in a raceway(s) containing the circuit conductors is outside "the" raceway(s) of implicit reference.

Now that we've established the EBJ is outside the raceway(s) of reference, it now must be installed in accordance 250.102(E), which essentially mandates it to be installed in "a" raceway if longer than 6 ft., but not necessarily "the" raceway(s) containing the circuit conductors.

 

[Smart $]

If it's not IN a raceway then it's OUTSIDE of the raceway.

A conductor can be in a raceway and still be outside another. It is even possible to be both inside and outside of a single raceway. The only condition is the same section of conductor cannot be simultaneously both.

 

[Pierre C Belarge]

Of course the inspector is correct.:grin:

Now, what was the question?:-?

Excellent, I could not have stated it better!!!


An equipment bonding jumper is in affect, a portion of the equipment grounding conductor.



Bonding Jumper, Equipment. The connection between two or more portions of the equipment grounding conductor.

Grounding Conductor, Equipment (EGC). The conductive path installed to connect normally non-current carrying metal parts of equipment together and to the system grounded conductor or to the grounding electrode conductor, or both.

300.3(B) Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment ground conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (B)(4).


If one is considering this a bonding jumper, then it will need to conform to 250.102(C). And 300.20 (if installed as a single conductor)

I still say that this is not a conforming installation as per the OP.

 

[crossman gary]

I'm with you, Pierre!

I think 300.3(B) is self-explanatory and everyone can agree on that.

Now, 300.3(B)(2) gives us an "out" for the bonding conductor. "Equipment Bonding Jumpers shall be permitted to be installed on the outside of raceways in accordance with 250.102(E)."

Okay, I understand that some of you are saying that the bonding jumper isn't inside of the "service raceways", meaning the 2 PVCs that contain the service entrance conductors. That is certainly one way to look at it.

So then there is the restriction to six feet when outside of a raceway from 250.102(E). But y'all are saying that we can negate the 6 foot rule by installing the bonding jumper in its own raceway. Well and good.

However, I just don't agree that is what it says. By the exact reading of the code, if a conductor is "outside of raceways" then a conductor that is inside of a raceway is not "outside of raceways". I do not think that 300.3(B)(2) is implicitly referring to only the raceways containing the circuit conductors. To me, "outside of raceways" means absolutely positively not in a raceway. It doesn't say "outside of THE raceway", it says outside of A raceway.

If a conductor is outside of a raceway, and then you put it in a raceway, it is no longer outside of a raceway, so it can't be installed outside of a raceway by the rule in 250.102. Man, this is too fun. :smile:

In this installation, the phase wires, the grounded conductor, and the bonding jumper are all components of the same circuit according to 300.3(B). And as such, we have THREE parallel conduits which contain portions of the parallel service entrance. And, each of these three conduits must meet the parallel conductor rules. You can't have phases in some and no phases in the other.

This is good stuff.:smile: I hope we can get some more good debate.

 

[crossman gary]

If one is considering this a bonding jumper, then it will need to conform to 250.102(C). And 300.20 (if installed as a single conductor)

The only problem with 250.102(C) is that pesky "where routed with" phrase.

But 300.20 is spot on. If there is a fault, the bonding jumper could certainly be carrying alternating current. Therefore, at the time of the fault, there would need to be slots cut in the metal trough to minimize the inductive heating and impedance effects.... it is probably best to have this done before the fault occurs.

 

[crossman gary]

I just ran across this too.

250.92(B) Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be maintained by one of the following methods:

1. Bonding equipment to the grounded service conductor...

2. Connections using threaded couplings or threaded bosses on enclosures....

3. Threadless couplings and connectors...

4. Other listed devices, such as bonding-type locknuts, bushings, or bushings with bonding jumpers.

So, simply running that 30 foot long bonding jumper in PVC between the trough and the panel doesn't meet the requirements above.... unless we put a "bushing with bonding jumper" into the equation.

Someone early in the thread mentioned that the grounded conductor must be used for the bonding. At that time, I was thinking it wasn't mandatory, just permissible. Now, considering the PVC, it seems to be a requirement.

 

[Pierre C Belarge]

Bonding jumpers are typically "short" (or at least shorter) conductors than are equipment grounding conductors, hence the definitions I posted.

On the supply side of the service, the issue I keep going back to in my mind is parallel paths and 250.102(C)/300.3(B)/300.20.

If, in the OP's installation he is not using the grounded conductor as the bond conductor on the supply side of the service, he has then installed an "EGC". With that said, it would be required to be installed in parallel with the ungrounded conductors.

If he has bonded the grounded conductor, then the "other conductor" installed is in parallel and will carry current, which makes it a current carrying conductor. With that said, bonding conductors and EGCs are not current carrying conductors. These are the issues that keep going through my mind.

So, if those of you who are disagreeing with my thoughts, educate me as to how I am thinking incorrectly.


P.S.
Draw this installation out on paper and you may see what I see.

 

[Pierre C Belarge]

I just ran across this too.

250.92(B) Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be maintained by one of the following methods:

1. Bonding equipment to the grounded service conductor...

2. Connections using threaded couplings or threaded bosses on enclosures....

3. Threadless couplings and connectors...

4. Other listed devices, such as bonding-type locknuts, bushings, or bushings with bonding jumpers.

So, simply running that 30 foot long bonding jumper in PVC between the trough and the panel doesn't meet the requirements above.... unless we put a "bushing with bonding jumper" into the equation.

Someone early in the thread mentioned that the grounded conductor must be used for the bonding. At that time, I was thinking it wasn't mandatory, just permissible. Now, considering the PVC, it seems to be a requirement.

I agree with this statement, as a consideration that needs to be addressed.

 

[hurk27]

If your on the supply side of the service disconnect, these are still service entrance conductors.
Just bond the CT cabnet to the grounded circuit conductor like you would in any meter can, remove the "bonding conductor" installed to the disconnect and be done with it. 250.142(A) clearly allows for this type of insulation, and most CT cabs I have installed have a means to bond the neutral or a phase conductor (delta) and there is no reson to run all the way to the service disconnect to do this bond.

I have never seen it done this way as in the OP

 

[Pierre C Belarge]

Hurk,
I said the same thing several posts back.
I am not sure if all here are reading the same thing though.

 

[SEO]

I agree with Hurk27 that would be the preferred method of bonding.

 

[crossman gary]

I just want to throw this out there again:

On the line side of the service, there is no prohibition against parallel paths for neutral current.

A simple example is a residential service with a metal nipple between the meter can and the panel enclosure. Neutral bonded to meter can and to panel. Parallel neutral current can/will flow in the enclosures and nipple.

 

[crossman gary]

I have never seen it done this way as in the OP

Me either, and using the grounded conductor is definitely the preferred method.

But the question is, does the installation in the original post meet the NEC requirements.

I say no.

 

[augie47]

and I say "yes"... in the end, the OP and his AHJ will make the determination :smile:

 

[chevyx92]

and I say "yes"... in the end, the OP and his AHJ will make the determination :smile:

Well in the end of all the arguing the inspector still wouldn't allow the install. We had to use the grounded conductor to bond the troughs. He also mentioned that the meyers hubs we used needed to be bonded but he wasn't going to push that and let it slide. I argued that the locknuts that come with are not a "Standard" Locknut and the teeth are there for a reason which is to dig into the metal and make a better bond than a standard locknut. He said they were not listed for bonding. Then why do meyers hubs have those slotted locknuts? And don't like this inspector. I still say he's wrong about the original install. IMO.

 

[Pierre C Belarge]

Meyers Hubs are listed as suitable for bonding purposes.

 

[chevyx92]

Meyers Hubs are listed as suitable for bonding purposes.

Not according to him. He said the locknut was suppose to have a screw in it.

 

[augie47]

More input would be interesting. At the Myers website, I found no mention of the "grounding standards" but did notice that the hubs I was checking had "bond screws". The only referece as to listing was UL 514 and I don't have a copy of that standard.