Loud Noise then Breaker trips when running Airconditioner

I've never seen a transfer switch underneath the RV
Never seen one that square size either or with a FAN

Never seem an inverter underneath the RV

do you mean AC as in the 120v input shore power House breaker
or A/C as in the 20amp breaker in the RV breaker panel, that is only for the A/C unit

Somebody could make weird mods, but it seems unlikely

PS
A/C is used for Air Conditioning
and
AC is used for POWER

so a statement like yours, can be a real Puzzler

are you tripping the breaker in the RV
or the one you are plugged into