The AC (outside fan, condenser, etc) runs for 15 to 20 minutes then trips the breaker. When it is running it is blowing cold air. I noticed the other day the pad had settled, so I leveled the pad & unit and it ran for a couple of days w/o any troubles. Now it is back to blowing the breaker??

High current draw is the problem.

Could be the compressor run capacitor.
Could be a weak breaker.

If you take a amprobe reading you can compare it to the label on the outside A/C unit.