I have an installation here in NY (2008 NEC) with a subpanel in a detached garage. I have not done a job with this architecture, and would appreciate feedback from the forum. Thanks.
This subpanel currently has a 100A breaker (busbar rated at 125A) with #2 ALU (100A) feeders.
The feeders come from a 100A breaker mounted in the a 200A service panel in the main house about 70' away.
I have 40A of inverter output (32A x 1.25).
I'd like to simply backfeed the breaker in the subpanel...downsizing the subpanel breaker to 80A will keep me to 120% regarding the subpanel busbar. One concern I have is whether or not I have to calculate the load on the #2 ALU feeder conductors at 120%, as it will still be a 100A breaker "supplying power to the conductor" from the main service panel.
It seems to me that I might have to also downsize the breaker in the main service panel in the house to 80A.
This subpanel currently has a 100A breaker (busbar rated at 125A) with #2 ALU (100A) feeders.
The feeders come from a 100A breaker mounted in the a 200A service panel in the main house about 70' away.
I have 40A of inverter output (32A x 1.25).
I'd like to simply backfeed the breaker in the subpanel...downsizing the subpanel breaker to 80A will keep me to 120% regarding the subpanel busbar. One concern I have is whether or not I have to calculate the load on the #2 ALU feeder conductors at 120%, as it will still be a 100A breaker "supplying power to the conductor" from the main service panel.
It seems to me that I might have to also downsize the breaker in the main service panel in the house to 80A.