Meter base to main panel board. Egc or not?

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wwhitney said:
Agreed on the above, but I didn't read #2 to imply improper use of lugs in the meter base. Assume all lug use is proper, with perhaps an extra lug bolted to the meter can for the extra SSBJ.

Cheers, Wayne
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The poster said this, which implies the lug had two conductors.
2.) Meter can on exterior of structure with GEC on Neutral lug in meter can, 4 wires in metal conduit to main panel, (#4 green insulated conductor from neutral lug shared with GEC to an added grounding bar mounted inside main panel).
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wwhitney said:
To which I would ask why unintended current on an SSBJ would be "objectionable" but unintended current on a metal service conduit is not?
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Remember the saying that the NEC views a meter as "a lump in the service cable." In every meter base I've seen, the neutral terminals are bonded to the can; thus, any metallic conduit connected to it becomes a part of it.

The entire assembly of service conduit(s), meter enclosure(s) and service disconnect(s) essentially are part of the utility neutral, receive electrode connection(s), and collectively define the zero-volts reference for the premises.

That's why I often say that there is no EGC ahead of the service, because there's nothing that needs bonding (other than some nipple or conduit terminations), and the premises EGC system only exists from there downstream.
 
LarryFine said:
Remember the saying that the NEC views a meter as "a lump in the service cable." In every meter base I've seen, the neutral terminals are bonded to the can; thus, any metallic conduit connected to it becomes a part of it.

The entire assembly of service conduit(s), meter enclosure(s) and service disconnect(s) essentially are part of the utility neutral, receive electrode connection(s), and collectively define the zero-volts reference for the premises.

That's why I often say that there is no EGC ahead of the service, because there's nothing that needs bonding (other than some nipple or conduit terminations), and the premises EGC system only exists from there downstream.
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If you would have other enclosures in the service conductor pathway they will be required to be bonded to the grounded conductor as well, that bond may or may not occur within the enclosure but if there is the chance of said enclosure being a parallel path with the grounded conductor simply because it is bonded.

Most typical overhead supplied services you don't bond anything until you reach the meter socket, all you have ahead of it is raceway and a weatherhead and they are naturally bonded by being connected together and to the meter socket, so that mostly leaves the raceway between meter and service disconnect as the only portion that normally has a potential parallel path.

If you have multiple service disconnects and/or multiple meters and a metal wire way between them, there is another somewhat common situation where there is a potential parallel path.
 
kwired said:
If you would have other enclosures in the service conductor pathway they will be required to be bonded to the grounded conductor as well, that bond may or may not occur within the enclosure but if there is the chance of said enclosure being a parallel path with the grounded conductor simply because it is bonded.

Most typical overhead supplied services you don't bond anything until you reach the meter socket, all you have ahead of it is raceway and a weatherhead and they are naturally bonded by being connected together and to the meter socket, so that mostly leaves the raceway between meter and service disconnect as the only portion that normally has a potential parallel path.

If you have multiple service disconnects and/or multiple meters and a metal wire way between them, there is another somewhat common situation where there is a potential parallel path.
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Agree with all, which is what I mean when I say that the metallic service enclosures and raceways are seen as part of the service neutral, rather than a separate, parallel pathway to it.
 
I'm not seeing anything in the text of 250.6 that would distinguish between neutral current on metal service conduit and neutral current on a bonding jumper inside that conduit. Seems like either they both are objectionable or neither is objectionable.

Cheers, Wayne
 
wwhitney said:
I'm not seeing anything in the text of 250.6 that would distinguish between neutral current on metal service conduit and neutral current on a bonding jumper inside that conduit. Seems like either they both are objectionable or neither is objectionable.
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What about paralleled-conductor rules?
 
LarryFine said:
What about paralleled-conductor rules?
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I agree that would/could be an issue if the unnecessary SSBJ were terminated on the same multi-hole lugs as the neutral conductor at both ends.

But if at either end conductivity between the neutral and the SSBJ depends on the metal case, then they are not "electrically joined at both ends". (*)

Cheers, Wayne

(*) That phrase "electrically joined" is not used elsewhere in Chapter 3. IIRC I submitted a PI for the 2020 NEC that would have amended the phrase with the word "directly." The CMP response was to the effect that "electrically joined" was different from "electrically connected" and implies a direct connection, as opposed to just having some conductive pathway.
 
wwhitney said:
I agree that would/could be an issue if the unnecessary SSBJ were terminated on the same multi-hole lugs as the neutral conductor at both ends.

But if at either end conductivity between the neutral and the SSBJ depends on the metal case, then they are not "electrically joined at both ends". (*)

Cheers, Wayne

(*) That phrase "electrically joined" is not used elsewhere in Chapter 3. IIRC I submitted a PI for the 2020 NEC that would have amended the phrase with the word "directly." The CMP response was to the effect that "electrically joined" was different from "electrically connected" and implies a direct connection, as opposed to just having some conductive pathway.
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I believe that still qualifies as electrically joined. The panel's bonding screw or jumper makes that extra conductor redundant (and thus parallel), even through the enclosure.
 
LarryFine said:
I believe that still qualifies as electrically joined. The panel's bonding screw or jumper makes that extra conductor redundant (and thus parallel), even through the enclosure.
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You made me look up my PI. It was for the 2023 NEC, 3482-NFPA 70-2020, and it proposed changing "electrically joined at both ends" to "electrically and physically joined at both ends" in 310.10(G). To clarify that those parallel conductor rules only apply to conductors directly joined at both ends, not conductors that happened to be electrically connected via some other route.

The panel response was "Electrically joined conductors will also be physically joined." I.e. in their view "electrically joined" already means "physically joined." And I would say that implies that a SSBJ that is connected at each end to the neutral service conductor via lug-enclosure-neutral bar is not subject to 310.10(G).

Cheers, Wayne
 
ok
Help me with Supply side bonding jumper?
In the previous scenarios, the only one qualifying as a SSBJ would be in scenario 2 which I think most of us agree is not compliant. (unless you consider the metal conduit connection)
If the conductor in scenario 2 was landed to a conduit bonding ring, then it would be compliant?
 
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