I’m planning to get a Honda eu7000 (or possibly a Yamaha 6300) as backup (I’m in Northern California). My main electrical panel is located on the exterior of my house. I have a sub panel inside the house. There is a breaker on the main panel which is labeled “sub panel“. One electrician told me that powering the main panel circuits is no problem but powering the circuits on the sub panel would require running a wire between the two panels at great expense. Another electrician told me that such a wire wasn’t necessary...that both panels could be powered running a wire between them. I’m confused! Is anyone out there familiar with these things? If any additional information needed to answer the question, I can try. Thanks.