Backfeeding SubPanels from Solar Arrays

[NorthwestPV]

With a 100A 240 volt service you could backfeed with a maximum of a 20A 2 pole or double breaker.
However check with the manufacturer it generally costs them more to produce different rated buss assemblies than to use the same buss bars in say a 100 amp panel and a 200A panel.

This is almost correct, actually no it's not. If your shop only has a 40A load, you could install a 40A breaker on the feeder in the service and install a 80A backfed breaker for the PV. The shop feeder and bus would need to be rated for 100A and would need to backfeed a 40A breaker for the main of your shop. This would satisfy the 120% rule for the service panel, shop panel, and shop feeder conductors.

[green]

This is almost correct, actually no it's not. If your shop only has a 40A load, you could install a 40A breaker on the feeder in the service and install a 80A backfed breaker for the PV. The shop feeder and bus would need to be rated for 100A and would need to backfeed a 40A breaker for the main of your shop. This would satisfy the 120% rule for the service panel, shop panel, and shop feeder conductors.

He was actually answering my question about just a main service panel and not a sub. Sorry to the OP I kinda jumped in with a related question, didn't mean to confuse.

Green

[Belldiver]

Sorry to the OP I kinda jumped in with a related question, didn't mean to confuse.

Green

No worries! I'm soaking up information too!
I got my basic question answered. It's possible, but would just have to make sure the installers electricians know how to read the NEC and get everything safe and legal.

I don't plan on doing this myself, just want to know enough to make sure the guys are doing it correct.

Jim

[Naptown]

This is almost correct, actually no it's not. If your shop only has a 40A load, you could install a 40A breaker on the feeder in the service and install a 80A backfed breaker for the PV. The shop feeder and bus would need to be rated for 100A and would need to backfeed a 40A breaker for the main of your shop. This would satisfy the 120% rule for the service panel, shop panel, and shop feeder conductors.

Actually it is correct. I was not responding to the question of backfeeding the shop sub panel but backfeeding the main 100A service not the sub panel.
This was another question by another poster that was a bit off this topic.