Yahoo Message Number: 64106 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/64106)
Ron,
In my coach the low/high voltage protection is set at 106 and 132 volts. Both of these values are at the extreme end of the safe operation of virtually all 120 volt equipment You do not want to run appliances for very long under these conditions so the cutoff opens until the voltage is back in it's normal range.
However various appliances are sensitive to low/high voltage at different levels. While some can run almost indefinitely at 109 volts others would suffer loss of life operating at that range. The idea of an autotransformer is to remove the risk of operating with marginal voltage by regulating it back to the midpoint value of 120 volts. The autotransformer itself has an operational range so it can not regulate extremely low voltage. One still needs the low/high cutoff switch.
While both pieces of equipment focus on voltage levels they do it from an entirely different perspective and are not redundant. They complement each other.
Don Seager
2004 Allure 31046