Tom, we use the Hughes Auto former when voltage is low along with an external Southwire 50 amp surge protector. You can use the Hughes voltage booster but it is not an active surge protector, in other words it will not monitor and shut down if voltage is low or unsafe. Your built in Southwire transfer switch will actively monitor voltage and give your coach protection. The Hughes Auto Former will give you another layer of protection and sacrifice if a major electrical event happens.