A transfer switch with a relay to automatically switch when an extension cord is attached can switch back and overload the 30-amp circuit breaker causing a complete loss of power. If it is too hot to take your pet with you in your car, it is too hot to leave your pet in an RV without power.
The solution is to have an RV transfer switch that uses a switch instead of a relay. Safe RV Power transfer switches incorporate two circuit breakers interconnected to form the switch. These circuit breakers are UL 489 certified to interrupt 5000 amperes and the Safe RV Switch has been tested to operate 5000 times without failure. The circuit breakers are Hydraulic/Magnetic style to provide reliable starting of air conditioners. They act independently of outside temperature from -25 to 125 degrees Fahrenheit. They provide protection should the auxiliary power cord be connected to a 30-Amp or 50-Amp receptacle by use of adapters. An automatic transfer switch may not provide this level of protection.