Sizing GEC when ungrounded conductors upsized for VD

[Giark]

I need to provide a GEC for a solar carport. I have had to upsize the conductors from the carport to the service to compensate for voltage drop. What conductor size should I use from 250.66; the minimum size required by the system amperage or the actual installed conductor size?

 

[petersonra]

what is a solar carport?

 

[Dennis Alwon]

Are you talking about the ECG not the gec? If so look at 250.122(b)