KD4UPL
Member
- Location
- Swoope, VA
I'm working on a rather large residential solar system with battery back-up. The array is located on a pole barn roof 1,200 feet from the house. I've got a #8 copper EGC coming down off the roof with the PV circuit conductors (also #8 copper). At grade the #8 copper is spliced to 1/0 Aluminum for the run to the house. It seems like I should have a ground rod at this building per 690.47D but I know that's a very controversial piece of code. This building is served by it's own 200 amp AC service from the power company which has nothing to do with the solar system but I guess I could bond my solar ground to the barn's AC GEC.
At the house I have a large battery bank feeding 48v DC to 3 inverters with parallel 4/0 DC conductors. Each inverter has a 250 amp DC breaker. Does this size battery cable dictate that my DC GEC needs to be a 3/0? The DC GEC will connect to the home's AC grounding electrode which is just two ground rods connected with #6 bare copper. Given that the AC GEC is #6 it seems crazy to connect my DC GEC to it being 3/0. Wouldn't I only need a #6 DC GEC since it's going to ground rods?
Thanks for you help on this one.
At the house I have a large battery bank feeding 48v DC to 3 inverters with parallel 4/0 DC conductors. Each inverter has a 250 amp DC breaker. Does this size battery cable dictate that my DC GEC needs to be a 3/0? The DC GEC will connect to the home's AC grounding electrode which is just two ground rods connected with #6 bare copper. Given that the AC GEC is #6 it seems crazy to connect my DC GEC to it being 3/0. Wouldn't I only need a #6 DC GEC since it's going to ground rods?
Thanks for you help on this one.