The acceleration time is to determine the time required for AC motor drive ramp from 0.0Hz to its maximum output frequency. The deceleration time is to determine the time required for AC motor drive to decelerate from its maximum output frequency to 0.0Hz. When an AC motor drive operates in a full load condition, large load inertia is likely to occur and cause motor continues to ramp when the output is stopped. Delta’s AC motor drive offers “optimize acceleration and deceleration function” that regulate the accelerating and decelerating speed. It moderates the vibration when activating and stopping the loading. As the motor detects a minimum level of torque, it will accelerate to the setting level of frequency in the shortest period of time with a smooth start-up current. For deceleration, Delta’s AC motor drive will estimate the amount of regenerative energy that will be produced and smoothly stop the motor in the meanwhile.