We have an 8 yr old Miller 5 ton 13 SEER AC unit, just about two weeks ago it blew one of the two 45amp fuses that are located between the unit and the house, we replaced the fuses and now it is blowing a fuse every couple of days. What are the possible causes?

The unit is drawing too much current/power and in turn blowing the fuse. It could be loose electrical connections or something as simple as the unit needs a good cleaning of the outside unit. Now it is possible that a electrical component is starting to go bad or if your unit has a hard start kit installed the relay or capacitor could be on its way out. Sorry but there is not a simple solution to this type of problem.

Thank you. Is there any way for the home handyman to check any of the issues you've mentioned? We do not have a hard start kit installed. We are in the desert southwest if that makes any difference...

Is there any way for the home handyman to check any of the issues you've mentioned

Not unless the home handy man has the proper tools and knows how to use them. You have a intermitent problem to start with so finding the exact cause will be difficult for a professional. Might start by tightning all the electric connections from the main panel all the way to the unit.