What is the difference between service rated and non service rated?

When installing a transfer switch that will supply power to your entire home, the transfer switch needs to be installed between the "SERVICE ENTRANCE DISCONNECT" and the main distribution panel. If your home utilizes a main breaker that's part of the main distribution panel, then you'll need to have a "SERVICE ENTRANCE DISCONNECT" installed, either separately, or as part of a "SERVICE ENTRANCE RATED" transfer switch.