I have an AC unit that I replaced the condenser fan in last year. This year during a storm the AC breaker on the inside of my house went bad. I replaced it and the AC worked fine for a few day. Last night I noticed the breaker had tripped. I reset the breaker and it runs for about 15-20 min. and then trips again. Does anybody have any ideas what might cause this?

Thanks

Take the garden hose and give it a good cleaning.

There are other possibilities. Since you mentionsed a storm, it's possible that windings of the motor/compressor were damaged.

A full diagnosis is required, particularly current draw and possibly insulation resistance testing.