Is it Ok to have 2 different size fuses in the outside shutoff box? I have a 20 amp and a 30amp fuse. Could this cause the compressor to blow? The max amp is 30 on the AC cover
Both fuses should be 30 amps. The fuses should be dual element, slow blow type.
You likely will not hurt the system, but the 20 amp fuse will most likely open at the most inopportune time.