Get an electrician to examine the circuit breakers (or fuses) & wiring.
Verify that the correct amperage circuit breakers/fuses for the A/Cs are in the fusebox.
If the fusebox is older than 10 years or has aluminum wiring,the electrician can examine the condition of the wires & breakers.
It's not unusual for loose wiring to cause the circuit breaker to become hot & "trip".