I am not a contractor but I bought the WGen9500DF for peace of mind! I live about 1/4 mile off the road and the power to my house has been there for many, many years. I'm sure if there if there is an outage and a problem with the lines coming from the road, I would be one of the last to have it repaired. The generator was easily set up and the directions were easy to follow. It runs like a charm! Peace of mind, thank you.