Separating Neutral and Ground in Main Panel

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SAS

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During the home inspection for our new house, the inspector noticed that the neutrals and grounds in the main panel were wired together under the same screw, which is not allowed. The problem I have in separating them is that there are not enough available slots on that side of the panel, and the existing wires are too short to bring around to the other side. Do I have to add a jumper for each ground wire I remove, or can I tie more than one together? If so, how many can be combined on one jumper? What size copper wire do I need to use for 2, 3 or 4 grounds combined togehter?
 

wwhitney

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Turn off the main breaker before you start lifting neutral conductors, unless you know how to recognize an MWBC and can identify all the breakers associated with a neutral conductor to turn off just those breakers. Read the torque ratings on the panel label inside and use a torque screwdriver.

The panel manufacturer may have an EGC terminal bar kit that you can bolt onto the backplane of the panel near the neutral bar, then you can just move all the EGCs to it.

1 neutral (grounded) conductor per terminal bar hole. Do not pigtail them together unless you know what an MWBC is and know how to create one.

The number of allowable EGCs in a single hole should be on the panel fine print label inside. It's usually at least 2 and may be 3.

If you have a wirenut or other connector (e.g. Wago 221) that is rated for, say 5 (or N) #12s, you can take 4 (or N-1) #12 or #14 EGCs off the terminal bar, connect them together to a #12 jumper wire, and land that jumper on the terminal bar.


Cheers, Wayne
 

SAS

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Thanks for the responses. I won't have access to the house, and therefore the panel, until next week. All I have right now is the photo from the home inspector, and it only shows a portion of the panel wiring.

So, next step will be to find out the make and model of the panel and the allowed connections per lug for that panel. I'll also then how many EGC's I need to move. If it's OK to to bundle as many as 4 EGC's together, I think I'll be able to do this without having to add another terminal bar, particularly if I can put two ECG under one screw.

And I never work on the main panel without throwing the main breaker. I'm not sure that anyone ever should, although my late father, a licensed electrician, routinely did.
 

wwhitney

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As to the bundling question, I picked 5 out of a hat. You can put as many as you like in a connection, and run one jumper sized equal to the largest EGC back to the ground bar. But adding a ground bar would give you a neater result.

Cheers, Wayne
 

SAS

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As to the bundling question, I picked 5 out of a hat. You can put as many as you like in a connection, and run one jumper sized equal to the largest EGC back to the ground bar. But adding a ground bar would give you a neater result.

Cheers, Wayne
Thanks, Wayne. Do you use a jumper to connect the additional ground bar or is it grounded via it's connection to the panel box? Or does it vary by manufacturer?
Steve
 

wwhitney

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The cabinet is an acceptable bonding path between the additional ground bar and the primary ground bar. I might still add a jumper between them for a warm fuzzy feeling, but maybe I've gotten beyond the idea that EGCs should be of the wire type.

That is not the case if you were adding an additional neutral bar in a service panel, even though neutrals and grounds are often mixed on the same terminal bar in a service panel. The neutral path for any circuit can't rely on the cabinet, so a neutral conductor needs to land on a terminal bar connected to the neutral service conductor directly or with jumpers. Not sure about whether in a service panel the additional neutral bar could still be mounted to the cabinet, rather than insulated from the cabinet. [It would create an additional neutral-ground bond, but as it's all within one panel, maybe that's OK.]

Cheers, Wayne
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