Question about bonding in a breaker panel

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Hi I considering buying a home in Loganville, GA. and had a home inspector look at the electrical system in the home that he said it was fine. I was looking over his shoulder during the inspection and am not sure he is correct about the panel being wired correctly. I have some questions about the neutral and ground bus bar bonding at the service panel.

Outside the home there is a 200A single phase Meter Base that has a service disconnect. From there is 4 wire feeder cable going to the service panel inside the home (separate ground and neutral and the two 120V legs). Both the ground and the neutral wires of the feeder cable are bonded together in the meter base box on the outside of the house. Inside the service panel in the house the feeder cable connections are as follows: ground wire connects to the ground buss bar and the neutral wire connects to the neutral buss bar. Also there is a #4 AWG bare copper ground wire going from the ground buss bar in the service panel to two ground rods outside the home. The ground buss bar and the neutral buss bars are bonded together in the service panel inside the home. I also noticed that the neutrals and ground wires from the individual circuits were mixed on the ground and neutral bus bars.

So my question is, since the meter base outside has the disconnect shouldn't the ground and neutral buss bars in the service panel be separated (remove the bonding bar that runs between them), the bare #4 AWG copper wire for the ground rods be moved to the meter base where the neutral and ground feeder cables are bonded together, and the mixed neutral and ground wires in the service panel be installed on the correct buss bars? I'll have the current home owner get an electrician to make the changes if this needs corrected before I close on the home.

Chris
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
You are correct in that the neutrals and grounds should be separated at the sub panel inside the house. They should be bonded together at the service disconnect only
 

kwired

Electron manager
Location
NE Nebraska
And any grounding electrode conductors need to be moved to the service disconnect or any point ahead of the service disconnect.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
I agree about the set up not being code compliant, but have a couple questions since I have seen similar set ups in the past.

Was it ALWAYS a requirement to keep the grounds and neutrals separate in the sub panels?

What is the real life hazard of current flowing on the ground conductor going from the disconnect to the breaker panel?
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I agree about the set up not being code compliant, but have a couple questions since I have seen similar set ups in the past.

Was it ALWAYS a requirement to keep the grounds and neutrals separate in the sub panels?

Yes. I've have yet to see documentation that states that this not required.
 

kwired

Electron manager
Location
NE Nebraska
I agree about the set up not being code compliant, but have a couple questions since I have seen similar set ups in the past.

Was it ALWAYS a requirement to keep the grounds and neutrals separate in the sub panels?

What is the real life hazard of current flowing on the ground conductor going from the disconnect to the breaker panel?
Was acceptable to use a grounded conductor only (no separate EGC) to supply separate buildings/structures.

What is the hazard(s)?
Potential unintended paths carrying neutral current.

Rise in voltage (because of voltage drop on current carrying grounded conductor) over "true ground".
 

tom baker

First Chief Moderator
Staff member
I agree about the set up not being code compliant, but have a couple questions since I have seen similar set ups in the past.

Was it ALWAYS a requirement to keep the grounds and neutrals separate in the sub panels?

What is the real life hazard of current flowing on the ground conductor going from the disconnect to the breaker panel?

Neutral and ground are in parallel. If the neutral was to open that would put all the neutral on the ground, potential for shock and fires, improper operation of electronic equipment, loss of 0 volt reference..
 
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