Failed Inspection

[dsarvis000]

I failed an inspection today bc I landed my wire for the water bonding in a lug that I installed into my main panel (bonded) and not into the actual neutral/ground bars installed on the panel.

The reason I was given was bc the water system was coming from underground and was metallic turning into an electrode and not a simple bond

My question is one is this correct, two if so where in the code does it say this, and three what’s the difference if the panel is bonded ?

 

[infinity]

If the main bonding jumper is a wire or a busbar the GEC can terminate on the EGC bus. If you used a green screw as the MBJ the inspector is correct. I don't have the code reference handy.

Welcome to the Forum.

 

[Joe Villani]

250.24(A)(1) (2017)

 

[dsarvis000]

If the main bonding jumper is a wire or a busbar the GEC can terminate on the EGC bus. If you used a green screw as the MBJ the inspector is correct. I don't have the code reference handy.

Welcome to the Forum.

Thank you for the insight, I do have a question about the green screw you mentioned. Is it not sufficient enough as a MBJ to be able to do what I explained in my post above?

 

[infinity]

Thank you for the insight, I do have a question about the green screw you mentioned. Is it not sufficient enough as a MBJ to be able to do what I explained in my post above?

The NEC does not think that a green screw or a bonding strap is sufficient to the point where they will not permit the GEC to land on the EGC bus instead of the neutral bus. It is sufficient as the MBJ for the purpose of bonding the neutral.

 

[dsarvis000]

The NEC does not think that a green screw or a bonding strap is sufficient to the point where they will not permit the GEC to land on the EGC bus instead of the neutral bus. It is sufficient as the MBJ for the purpose of bonding the neutral.

I see. Thank you again. That actually makes sense bc I’ve tested from a phase to the cabinet for 120v and sometimes it won’t read 120v, specifically residential panels

 

[dsarvis000]

The NEC does not think that a green screw or a bonding strap is sufficient to the point where they will not permit the GEC to land on the EGC bus instead of the neutral bus. It is sufficient as the MBJ for the purpose of bonding the neutral.

On top of that though, you would think the manufactures would correct that to make things more efficient, NEC compliant, etc etc but that’s neither here nor there.

 

[kwired]

I failed an inspection today bc I landed my wire for the water bonding in a lug that I installed into my main panel (bonded) and not into the actual neutral/ground bars installed on the panel.

The reason I was given was bc the water system was coming from underground and was metallic turning into an electrode and not a simple bond

My question is one is this correct, two if so where in the code does it say this, and three what’s the difference if the panel is bonded ?

Why didn't inspector tell you what code section you were in violation of? Especially if he actually failed you and filled out any paperwork. If he made you correct it while still there then passed it - different situation.

 

[infinity]

On top of that though, you would think the manufactures would correct that to make things more efficient, NEC compliant, etc etc but that’s neither here nor there.

If you think in terms of residential service panels only the best practice is to always land the GEC on the neutral bus. For things like large service switchboards (which will likely have bus bar MBJ) then you have the option to land the GEC's on the EGC bus.

 

[LarryFine]

Is it not sufficient enough as a MBJ to be able to do what I explained in my post above?

For EGCs, it is; for GECs, it is not. It follows neutral rules, not EGC rules.

This is about re-establishing the neutral as the service's zero-volts point.

 

[kwired]

This is about re-establishing the neutral as the service's zero-volts point.

Which I have found it rarely actually does.

If you happen to have a volt or so of voltage to earth on your grounded service conductor, you still have that same volt or so to earth on all the EGC's leaving the service equipment. About the only place NEC seems to recognize this is for swimming pools and agricultural buildings, and maybe certain health care situations. Everywhere else that voltage rise is considered acceptable, I guess.

 

[wwhitney]

I failed an inspection today bc I landed my wire for the water bonding in a lug that I installed into my main panel (bonded) and not into the actual neutral/ground bars installed on the panel.

Is that wire "the" GEC, the one that 250.64(C) requires be continuous without reversible splice, or is it just an electrode bonding jumper, as some other electrode is connected via a continuous GEC to the service grounded conductor?

In the former case, all of the previous answers apply. But in the latter case, the bonding jumper may be spliced, so I'm not seeing the problem. What section says that the service panel enclosure may not be used as a bonding jumper?

Cheers, Wayne

 

[tortuga]

A few years back one of our guys was doing a resi panel swap and due to the length of the old wire the (existing) water bond ended up on the factory installed equipment grounding bar but the ground rods and neutral were on the neutral bar, and the inspector rejected it.
I am pretty sure he let me jump a piece of bare #4 between the bars, as then they are joined but something other than the MBJ screw. They really prefer it to be all on the neutral bar, which is easy in new work.
They also don't like the bare from old 3-wire SE range and dryer cables landed on the equipment ground bar, even if the service becomes a sub panel.

 

[Elect117]

Is that wire "the" GEC, the one that 250.64(C) requires be continuous without reversible splice, or is it just an electrode bonding jumper, as some other electrode is connected via a continuous GEC to the service grounded conductor?

In the former case, all of the previous answers apply. But in the latter case, the bonding jumper may be spliced, so I'm not seeing the problem. What section says that the service panel enclosure may not be used as a bonding jumper?

Cheers, Wayne

Other than 250.24(A)(1)-(5).

250.68, 250.53(C),

GECs can only bond to each other in limited circumstances, busbar (250.64(F)/250.53), and where they terminate in 250.24(A).

If the water pipe is not a GEC and is just being bonded, then 250.104 for equipotential bonding.

None of the locations permitted are the service equipment enclosure. Though, when you use bonding bushings for metal conduit, on both ends of the conduit, you would be bonding it to the service enclosure before the conductor is terminated to the neutral bar.

I expect the use of the enclosure as a bonding conductor that is bonding the grounding electrode(s) to the neutral would to be an issue of objectionable current. Where more than one service / separately derived system is present and bonded to the same electrodes it might become a unintended path. In the instance of an open neutral you would be making the enclosure a path for neutral current as it tries to make it's way back through earth. I also wonder what effects that might have on lightning strike / surges.

 

[don_resqcapt19]

Which I have found it rarely actually does.

If you happen to have a volt or so of voltage to earth on your grounded service conductor, you still have that same volt or so to earth on all the EGC's leaving the service equipment. About the only place NEC seems to recognize this is for swimming pools and agricultural buildings, and maybe certain health care situations. Everywhere else that voltage rise is considered acceptable, I guess.

That voltage rise is still there in those locations, but you have simply raised the voltage of all conductive items within reach to that same voltage. A measurement to remote earth from those bonded locations will show the voltage rise.

 

[wwhitney]

Other than 250.24(A)(1)-(5).

250.68, 250.53(C),

GECs can only bond to each other in limited circumstances, busbar (250.64(F)/250.53), and where they terminate in 250.24(A).

OK, I didn't check all your references, because I don't believe you have addressed my point. Not every electrode has to be connected to a conductor that meets the rules for a GEC. In fact, only one electrode has to be so connected. The other electrodes can be connected to a conductor that meets the rules for an electrode bonding jumper.

So if the wire in the OP is in fact not required to be a GEC, but needs only be an electrode bonding jumper (unknown but plausible), then my question is, what specific section of the NEC is violated by using a bonding jumper to the neutral bus that consists of a wire, a lug on the enclosure, the enclosure itself, and the screw-type MBJ?

Cheers, Wayne

 

[LarryFine]

Which I have found it rarely actually does.

I'm actually referring to the neutral/EGC-system bonding, and service enclosures and conduits being part of the neutral and neutral-current pathway, not necessarily earthing it.

The main bonding jumper location is the point in the service that is considered the zero-volts reference for the premises, regardless of any voltage between the neutral and earth.

 

[LarryFine]

They also don't like the bare from old 3-wire SE range and dryer cables landed on the equipment ground bar, even if the service becomes a sub panel.

Especially if. I have been allowed to tape the bare wire white. It definitely belongs on the neutral bar.

 

[Elect117]

Not every electrode has to be connected to a conductor that meets the rules for a GEC.

"All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system. "

250.53(C) - "The bonding jumper(s) used to connect the grounding electrodes together to form the grounding electrode system shall be installed in accordance with 250.64(A), (B), and (E), shall be sized in accordance with 250.66, and shall be connected in the manner specified in 250.70. Rebar shall not be used as a conductor to interconnect the electrodes of grounding electrode systems."

250.64(A) is for copper or aluminum conductor.
250.64(B) is protecting the conductor.
250.64(E) is for the choking effect (bonding and both ends).
250.70 is for connecting the conductor

The enclosure is not a method allowed in 250.53(C) nor 250.64(F). Every part of the grounding electrode system would need to meet those requirements. 250.104 is for when there are metal pipes and other structural metal that do not meet the requirements of being an electrode.

then my question is, what specific section of the NEC is violated by using a bonding jumper to the neutral bus that consists of a wire, a lug on the enclosure, the enclosure itself, and the screw-type MBJ?

Maybe I am misunderstanding the question. But a grounding electrode system or grounding electrode conductor should not terminate to the enclosure prior to landing on the neutral terminal bar or the equipment grounding terminal bar (where allowed by 250.24(A)(4)).

The specific section is 250.24(A).

 

[wwhitney]

The enclosure is not a method allowed in 250.53(C)

250.53(C) does not provide an exhaustive list of methods/types of bonding jumpers. None of 250.64(A), 250.64(B), 250.64(E), or 250.70 explicitly rule out using the enclosure as a bonding jumper.

Let me draw your attention to 250.68(C). It says in effect that we can use the following items as bonding jumpers as part of interconnecting the electrodes: the first 5' of interior metal (not necessarily copper) water pipe in the building; the metal structural frame of the building; or a piece of rebar extending out of a concrete foundation which qualifies as a CEE. I would think the metal enclosure of a panel would be at least as good a conductor as any of those.

The specific section is 250.24(A).

Sure, if the wire in the OP is a GEC. But I don't see any requirements in 250.24(A) that apply to an electrode bonding jumper.

Cheers, Wayne