A/C flipping circuit breakers while travrlling

First thing that I would do would be to shut one off and see if the one runs. If then I would switch A/C units to see if the other one operates by itself. Next, I would start one with an amp meter in line to see what kind of amperage you are drawing at start up. Usually, A/C's take up to three times the running amerage to start. If everything looks good on both of them, I would check all of the connections in the breaker box, then work my way back to where power enters. Also, I would feel the breakers and see if they feel warmer than the others. If one is a lot warmer then the other then you may have a bad breaker. Since I don't know who the bus is wired, I can't tell you more than that. One thing that you might ask your dealer or repair person is does the A/C's have a soft start kit on them.