Grounding 400 A. C.T. that feeds 2, 200 A. main brk. pan

[skeet]

Do I ground the nuetral at the CT can and float the neutral at the panels or ground the nuetrals seperately at each panel? Seems to me the "service" is at the first point of disconnect which would be at the panels. But I feel like I should be doing my main grounding at the nuetral in the CT can. Any thoughts?

 

[ryan_618]

Re: Grounding 400 A. C.T. that feeds 2, 200 A. main brk. pan

250.24(A)(1) tells us that the main bonding jumper must be in the service equipment AKA "first point of disconnect".

 

[charlie]

Re: Grounding 400 A. C.T. that feeds 2, 200 A. main brk. pan

Ryan is correct with his statement. Additionally and as a general rule, everything on the line side (between the service point and the service equipment) of the service is grounded to the MGN (multi-grounded neutral).

 

[russ]

Re: Grounding 400 A. C.T. that feeds 2, 200 A. main brk. pan

I would allow you to treat each panel as a service.
Install the grounding electrode conductors based on the size of the service entrance conductor going to each panel.
Bond the GEC to the grounded neutral conductor in each panel.