Separating EGC and Neutrals in Main Panel & Sub Panel?

[death900]

To preface this, i have had an inspection fail before because the ground wires and neutral wires were not separated on isolated terminal bus within a panel before.

I have a main panel which is the service entrance of a dwelling unit, with a sub panel wired from it. There is no dedicated ground bus terminal in the main panel, all of the EGC, GEC and Neutral wires are terminated on the same common bus that also has the incoming service Neutral connected to it.

I understand that the service entrance needs to have a bonding jumper between the neutral and ground bus terminals;

https://www.whittinspections.com/wp-content/uploads/sites/51/2021/05/E15-Service_Panel-445x500-1.jpeg

, but there is no dedicated ground bus terminal in my main panel. Everything; service neutral, GEC to ground rod, EGC from branch circuits, Neutral from branch circuits, Ground bond to sub panel, Neutral bond to sub panel, are all terminated on the same neutral bus. And all of the GFCI breaker pigtails are also terminated on this same neutral bus as everything else.

First of all i dont believe that this is correct, despite that the service entrance needs a neutral → ground bonding jumper between the busses, but i also think this is why my GFCI breakers keep phantom tripping ALL THE TIME.

The GFCI pigtails should be terminated to the ground bus, NOT THE NEUTRAL BUS. Its detecting current and tripping because its terminated on the CURRENT CARRYING BUS.

Would like to know if i have this interpretation correct, thanks.

 

[infinity]

Where the MBJ is installed (which is what you're calling the main panel) the neutrals and EGC's can all terminate on the same bus. Any panel downstream of the main panel needs to have the neutral bus isolated from the enclosure and a separate EGC bus connected to the enclosure typically by two screws. GFCI pigtails are white because they get connected to the neutral bus.

 

[jaggedben]

What you've described is not why your GCFIs are tripping.

 

[death900]

There is no ground bus on the main panel (service entrance). Im reading that combining is ok, but idk i dont think that this installation is correct.

Ground rod, Service ground, Service Neutral, Branch circuit neutral & ground, Sub panel neutral and ground are all connected to the same common bus.

 

[jaggedben]

Looks okay from here.
As infinity said, in the panel where you'd have the main bonding jumper, i.e. where the service disconnect is, it's okay to have one bar. Electrically there is no important difference between one bar and two bars connected with a jumper.

 

[acrwc10]

There is no ground bus on the main panel (service entrance). Im reading that combining is ok, but idk i dont think that this installation is correct.

Ground rod, Service ground, Service Neutral, Branch circuit neutral & ground, Sub panel neutral and ground are all connected to the same common bus.

View attachment 2573856

the green screw in the upper right side of the neutral buss is the bonding jumper.

 

[LarryFine]

the green screw in the upper right side of the neutral buss is the bonding jumper.

Yes, it normally is, but since the EGCs are on the neutral buses here, it's only bonding the enclosure.

 

[death900]

I dug into the code and looked at more diagrams. It looks like this installation is correct. Will need to dig into the appliances more to figure out the GFCI issue, but it looks like this is right. Thanks all.

 

[Little Bill]

Yes, it normally is, but since the EGCs are on the neutral buses here, it's only bonding the enclosure.

It's still the bonding jumper. If the EGC had a separate bar, which would be connected directly to the enclosure, then the BJ would be bonding the EGC and neutral, and the enclosure.

 

[LarryFine]

If the EGC had a separate bar, which would be connected directly to the enclosure, then the BJ would be bonding the EGC and neutral, and the enclosure.

Absolutely. The neutral bus is the MBJ in this case, which is the only point I was attempting to make.

 

[infinity]

There is no ground bus on the main panel (service entrance). Im reading that combining is ok, but idk i dont think that this installation is correct.

Ground rod, Service ground, Service Neutral, Branch circuit neutral & ground, Sub panel neutral and ground are all connected to the same common bus.

View attachment 2573856

Everything is normal and code compliant. A separate EGC bus is not required where the MBJ is located.

 

[jap]

Not that it matters, but, is the red phase coming in being on the right of the main actually the top phase of the panel circuit's 1 &2 ? or
is the black phase 1 &2?
Red branch circuits wiring is landed on 2 and 6 and black is on 4 an 8.

Jap>

 

[infinity]

Not that it matters, but, is the red phase coming in being on the right of the main actually the top phase of the panel circuit's 1 &2 ? or
is the black phase 1 &2?
Red branch circuits wiring is landed on 2 and 6 and black is on 4 an 8.

Jap>

Eaton main breakers often cross the connections between the lugs and the bus. It likely that the red which is on the right is slots 1&2.

 

[jap]

Thanks,
Jap>

 

[PaulEd]

I'm sorry but it makes me a little suspect and nervous that the op doesn't know the difference between the main panel and subpanel neutral and bonding. It's pretty rudimentary

 

[jaggedben]

I'm sorry but it makes me a little suspect and nervous that the op doesn't know the difference between the main panel and subpanel neutral and bonding. It's pretty rudimentary

And yet it's one of the top reccuring subjects that people ask about here, and something I've also seen come up in the field repeatedly.
Must not be quite as straightforward as it seems to some of us. And this forum is here to answer peoples' questions and help educate. I think a lot of people these days get into the field without formal education or apprenticeship which is definitely something we could also talk about but in the meantime this forum might be one of the better resources these guys have.

 

[PaulEd]

And yet it's one of the top reccuring subjects that people ask about here, and something I've also seen come up in the field repeatedly.
Must not be quite as straightforward as it seems to some of us. And this forum is here to answer peoples' questions and help educate. I think a lot of people these days get into the field without formal education or apprenticeship which is definitely something we could also talk about but in the meantime this forum might be one of the better resources these guys have.

Agreed. Not trying to be a jerk.

 

[electrofelon]

It's still the bonding jumper. If the EGC had a separate bar, which would be connected directly to the enclosure, then the BJ would be bonding the EGC and neutral, and the enclosure.

Absolutely. The neutral bus is the MBJ in this case, which is the only point I was attempting to make.

Just to dive into this a little deeper: I have always thought the code wording is not so great in this area. Much of the wording in the code implies there is a grounded terminal bus, and a separate EGC bus, and they are connected by the MBJ (at the service disconnect). IF you look at the definition of "bonding jumper, main" and the photo from the OP, the green screw doesnt seem to be the MBJ.