Even though the A/C unit is outside, the breaker for it will be in the entrance panel box inside your home. It should be clearly marked.
That tells me the problem is with the outdoor unit. Most likely a dead compressor or fan motor. Additionally, your indoor and outdoor units are not on the same breaker.
The inside fan blows air through the ac coils to cool the air. It should be on a separate breaker or fuse circuit from the outside unit. See if there is a fuse box on the side of the inside unit and check the breakers in the house main breaker box. Also stand quietly beside the inside unit and listen for the fan motor running. If the motor is heard running then either the fan drive belt has broken, or the ac coils are clogged preventing air from flowing.
Yes
NO!
6millimeter square.
Read the literature for the ac condensing unit, or the tag on the outside of the unit. Minimum circuit ampacity= minimum breaker, wire and fuse size. Maximum circuit ampacity= the maximum size. Your circuit breaker, wire size and disconnect fuses should all be at or between those 2 numbers.
The wiring to the unit is either not on the right type of breaker switch or the unit is not hooked up directly to the breaker box at all.
RV AC units are interchangeable. This is true as long as you replace the whole unit and not just one part.
A commercial AC unit can be directly purchased from acdirect.com. They have multiple AC units both residential and commercial. They have many choices to chose from!
60amp
You will need to use #8 wire.