removing the ground from existing service

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dannyrzk

Member
Location
tulsa, OK
Morning, can somebody please explain the reasoning behind REMOVING THE GROUND FROM THE NEUTRAL OF AN EXISTING SERVICE ENTRANCE EQUIPMENT, AND GROUND TO NEUTRAL ON THE NEW SERVICE ENTRANCE EQUIPMENT?

Thanks!
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Morning, can somebody please explain the reasoning behind REMOVING THE GROUND FROM THE NEUTRAL OF AN EXISTING SERVICE ENTRANCE EQUIPMENT, AND GROUND TO NEUTRAL ON THE NEW SERVICE ENTRANCE EQUIPMENT?

Thanks!
Is the new service entrance equipment being installed on the line side of the existing service entrance equipment?
 

dannyrzk

Member
Location
tulsa, OK
"Is the new service entrance equipment being installed on the line side of the existing service entrance equipment?"



Yes that is correct, it is now the new service entrance equipment.

Thanks
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
"Is the new service entrance equipment being installed on the line side of the existing service entrance equipment?"



Yes that is correct, it is now the new service entrance equipment.

Thanks
The connection between the grounded conductor and the grounding system cannot be on the load side of the service disconnect, so you will have to move it to the new service disconnect. See 250.24(A)(5). You will have to separate the grounding conductors from the grounded conductor at the old service equipment and you will have to install a feeder between the new and old equipment that includes an EGC.
 

rlundsrud

Senior Member
Location
chicago, il, USA
"Is the new service entrance equipment being installed on the line side of the existing service entrance equipment?"



Yes that is correct, it is now the new service entrance equipment.

Thanks

That would mean that the new service entrance equipment would be the primary point of disconnect for the system if I understand your question. If that's the case the GEC should be connected there and the neutral bonded (with the supplied green bonding screw) to the panel. The original service now becomes a sub panel and cannot be bonded as this would potentially cause objectionable currents in the ground system. I hope that helps.
 

dannyrzk

Member
Location
tulsa, OK
The connection between the grounded conductor and the grounding system cannot be on the load side of the service disconnect, so you will have to move it to the new service disconnect. See 250.24(A)(5). You will have to separate the grounding conductors from the grounded conductor at the old service equipment and you will have to install a feeder between the new and old equipment that includes an EGC.


That explains it, thank you so much"
 

electricalist

Senior Member
Location
dallas tx
If this service equipment is fed from a xfmr( customer owned) as in a 480v -xfm- 208. The grounded and grounding conductors may be bonded there. Then they would be separated at the service equipment.
 

iwire

Moderator
Staff member
Location
Massachusetts
If this service equipment is fed from a xfmr( customer owned) as in a 480v -xfm- 208. The grounded and grounding conductors may be bonded there. Then they would be separated at the service equipment.

That is an impossible scnerio.

If there is a customer opened 480 x 208/120 transformer the service equipment would have to be located on the line side of it.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Mr.iwire what is it that I'm understanding in correctly?
That the secondary isn't called or considered service equipment.
If the transformer is customer owned, the secondary conductors are feeder conductors and not service conductors. Service conductors can only be
supplied by a direct connection to the serving utility. Any other source supplies feeders or branch circuits.
 
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