Neutral on a ground bar

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Emtziii

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Elecrician
The panel being bonded, why is it not okay to have the branch circuits neutrals on the ground bar and vice versa
 
Emtziii said:
The panel being bonded, why is it not okay to have the branch circuits neutrals on the ground bar and vice versa
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Whether it's OK or not, I have seen mixed G and N conductors on both bars many times.
 
ggunn said:
Whether it's OK or not, I have seen mixed G and N conductors on both bars many times.
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In the service equipment, often all of the bars are neutral bars and both white and green conductors are permitted to be landed on the neutral bar in the service equipment.

Where the additional bar in the service equipment is an EGC bar connected to the neutral only via the enclosure and main bonding jumper, it is not permitted. See 200.2(B)
200.2 (B) Continuity.
The continuity of a grounded conductor shall not depend on a connection to a metallic enclosure, raceway, or cable armor.
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The use of a neutral bar for the connection of EGCs on the load side of the service equipment is prohibited by 250.24(A)(5)
250.24(A)(5) Load-Side Grounding Connections.
A grounded conductor shall not be connected to normally non–current-carrying metal parts of equipment, to equipment grounding conductor(s), or be reconnected to ground on the load side of the service disconnecting means except as otherwise permitted in this article.
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don_resqcapt19 said:
In the service equipment, often all of the bars are neutral bars and both white and green conductors are permitted to be landed on the neutral bar in the service equipment.
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OK, but it's a real PITA for an installer when an ATS is installed ahead of an MDP with a bazillion EGC and neutral conductors all mixed on both bars.
 
ggunn said:
OK, but it's a real PITA for an installer when an ATS is installed ahead of an MDP with a bazillion EGC and neutral conductors all mixed on both bars.
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Not a code issue. You just have to add more time to your bid for that type of project. There is no electrical or code reason not to mix the conductors in the enclosure that contains the main bonding jumper, assuming that both bars are directly connected to the service neutral bar by busing or wires.
 
Emtziii said:
The panel being bonded, why is it not okay to have the branch circuits neutrals on the ground bar and vice versa
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"Objectionable current"
you don't want current on the ground from a distribution panel back to the main.
 
hbiss said:
The OP was talking about a main service panel with the neutral and ground bonded, typically residential. Nobody was talking about neutral and ground bars after that like in a sub panel.

-Hal
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Did he say "Main Panel" ? I must have missed that, but thanks for letting me know.
 
I have seen this a lot in sub panels on service calls ... always add a grounding bus to correct it.
 
For a main service, find the answer to your question by reading NEC Article 250.90.

Moreover, at the main service, one might consider the total metal enclosure (including screws) as a grounding conductor to the main bonding jumper, which is used for fault or ground currents. For this reason, the neutral conductors and equipment grounding conductors connect together.

However, at a subpanel the neutrals and equipment grounding conductors land on separate bars (408.41). By installing two separate bars, one for the neutrals and one for the equipment grounding, one controls the current flow in one direction back to the main service, which provides a path for fault or ground currents. Objectional neutral current could result when one errors at this point. Remember that the neutral is intended to and does carry current, and it needs to flow in one direction back to the main source.
 
LadyDi said:
For a main service, find the answer to your question by reading NEC Article 250.90.

Moreover, at the main service, one might consider the total metal enclosure (including screws) as a grounding conductor to the main bonding jumper, which is used for fault or ground currents. For this reason, the neutral conductors and equipment grounding conductors connect together.

....
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While everything is connected together in the service equipment enclosure, auxiliary grounding bars in the service equipment enclosure are often only connected to the enclosure and those bars cannot be used for the connection of neutral conductors. 200.2(B)
 
I think it's completely ambiguous whether the OP was talking about a service panel or a subpanel. Hopefully they come back, read LadyDi's reponse, and learn.
 
This is what the City of Los Angeles requires. See attachment
 

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  • City of Los Angeles - Water pipe bonding, 08-03-2015.pdf
    1.2 MB · Views: 22
This is what the County of Los Angeles requires. See attachment
 

Attachments

  • Electrical Service Detail - Los Angeles County.pdf
    58.1 KB · Views: 7
Emtziii said:
The panel being bonded, why is it not okay to have the branch circuits neutrals on the ground bar and vice versa
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1. Enclosure is not allowed to carry the neutral current. If you land the neutral on the cabinet ground bus the neutral current would have to travel on the enclosure to get back to the service neutral. No different than trying to use the grounding conductor as the neutral.
 
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