The existing building has a piece of switchgear fed thru a outside junction box then goes to the Poco transformer.There is now a addition and I am wanting to add another panel beside the existing and feed from same junction box, does this still qualify as one service. The transformer and secondary wires can carry the new load. The existing bond to the building steel is based on parallel #3/0cu , the new panel will have parallel #750al. do I leave existing bond intact and add another for new panel. The Gec system is 2 ground rods only and I don't believe I can access the rods(poured over with concrete ) so would you drive 2 new rods and loop both panels thru these. I am sorry for all the questions just dealing with old existing and trying to wrap my head around this. I am fine on the 6 disconnect rule.
Question on adding service
- Thread starter KWH
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JoeStillman
Senior Member
- Location
- West Chester, PA
- Occupation
- Electrical PE
It's one service with multiple disconnects. You need to see article 250.64(D)(1). There has to be a common GEC. If you have an NEC Handbook, there's a nice picture on page 244.
I have found the key when dealing with "old existing" is asking the AHJ.
He might accept you tapping on the existing GEC to the rods or he might, and probably will, want two new rods and a GEC bond jumper since thats the only electrode system you have.
Keep in mind GECs to the ground rod can be sized 250.66(A) (#6).
He might accept you tapping on the existing GEC to the rods or he might, and probably will, want two new rods and a GEC bond jumper since thats the only electrode system you have.
Keep in mind GECs to the ground rod can be sized 250.66(A) (#6).
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