Dry camping last weekend with my 29h. It is equipped with a inverter to power tvs and player. Wanted to use microwave so I started gen. That got me thinking! How does the tv switch from invertor to shore/gen power? Only transfer switch I know of is for gen to shore power. it works great but just got me thinking.
The TV doesn't know your source of AC power and it doesn't care. It can be from shore, generator or inverter if you have one. The transfer switch detects the 120 source and shuts. If more than one source is present it has a priority.
So as was mentioned - there are really TWO transfer switches...
The RV main transfer switch controls whether power is being fed from Shore or Generator. That then passes to the distribution panel...
In the circuit for the TV you have an inverter - that also has two inputs - 110v and 12v - and its own transfer switch that determines what is connected. It will always give priority to 110v if present to conserve batteries.
So whatever combination of shore/generator/inverter you try - the transfer switches keep each supply source isolated - and only one powering a particular device.
The inverter will when you are not connected to shore, or the generator, convert 12 volts to 120 and supply the outlets and appliances they are wired to. When you plug into shore power, or start the generator, the invertor simply allows the voltage and current to pass through.