The users can select the adequate regenerative resistors according to the allowable frequency required by actual operation and the allowable frequency when the servo motor runs without load. The allowable frequency when the servo motor run without load is the maximum frequency that can be operated during continuous operation when servo motor accelerate from 0rpm to rated speed and decelerate from rated speed down to 0rpm. The allowable frequencies when the servo motor run without load are summarized in the following table. When the servo motor runs with load, the allowable frequency will change according to the changes of the load inertia and rotation speed. Use the following equation to calculate the allowable frequency. m = load/motor inertia ratio The users can select the adequate regenerative resistors according to the allowable frequency by referring to the table below: