An outdoor air conditioner unit is sensitive to power quality. Wrong cable size, loose contacts, an unsuitable breaker or voltage drop can cause trips and hard compressor starts.
An electrician should check the dedicated line, cable size, breaker, RCD, grounding and voltage during compressor start. Outdoor cable must be protected from moisture, sun and mechanical damage.
If the breaker trips, lights flicker at startup, the connection box gets warm or faults appear after rain, the line should be professionally inspected.