Greetings could someone post an anwser to the group for the following:

I have a home that is about 20 years old. The sub-panel in the
basement is a 100 AMP panel. I have an aluminum wire that runs from
the panel to a new airconditiong unit I had installed recently. The
wire reads:
SE Cable Style U Type XHHW CDRS 600V 3 CDRS 6 AL (UL) 1983

I currently have a 40 AMP breaker installed that keeps tripping after
the AC unit cycles on and off a few times. The AC guy that installed
it said to put in a 50 AMP breaker but I can't find the information to
see if this wire can take that size breaker. If someone can help me
find the info or if you know for sure that a 50 AMP breaker is OK,
could you please let me know?

PS The AC unit says it can take a max breaker of 60 AMP.

Thanks

Joe