roof air question

its tripping the air cond breaker sometime if it does not kick in and start blowing it will kick the breaker so this might be a compressor capacitor is what one person said how would i check these capacitors to see if their good i know its has two one for the motor and one for the compressor.i know they sometime swell up or leak . but how do i check it with volt meter.the motor run fine on high amd low on fan . but like i said when i switch it too low or high air it may take it a min to start blowing if it dont kick breaker first.