re: Generator tied into main fuse box - natural gas or propane powered

An automatic transfer switch will require a genset be large enough to run the entire house load per the NEC.

Anything smaller will require a manual transfer switch or some type of interlock kit which will not allow the power to backfeed to the utility company.


See below for code complaint interlock kits which allow you to tie the genset directly to your panel. They must be ordered for you exact panel.

Loadcenter Interlock kits