AC service disconnect keeps blowing fuses
The feed to the panel looks like #6 al and aluminum wire can loosen over time and with load. I'd check the connections in the panel. 
You can change the fusible disconnect to a non fusible one. Make sure it is rated for aluminum cable. You would need either a 30 or 60 amp depending on what you find when you get the name plate info. You've got breakers for the compressor and the air handling unit so make sure you know which ones are which, though the breakers for the air handler would be higher amperage if there's a strip heater in it.