Slip, a crucial aspect of VFD operation, can significantly impact the performance and efficiency of electric motors. To monitor slip, one can use a VFD display, a multimeter, a tachometer, or a speed sensor. The VFD display shows frequency, voltage, current, power, and speed of the output; a multimeter can measure voltage and current of the input and output; and a tachometer or speed sensor can measure the motor's actual speed. By comparing these values, one can detect any deviations or anomalies from the expected range. Common causes of excessive or insufficient slip include incorrect VFD settings such as frequency, voltage, acceleration/deceleration/ramp time; loose/damaged wiring/connectors/terminals; faulty/worn-out motor components like bearings/windings/rotor bars; overloaded/underloaded motor/VFD; and environmental factors such as temperature/humidity/dust/vibration. To troubleshoot these problems, one should check and adjust VFD settings, inspect and repair wiring and motor components, reduce or increase load, and improve ventilation and cooling of the motor and VFD. By understanding how to measure, adjust, optimize, monitor and troubleshoot slip, you can improve your VFD skills and bolster applications that use VFDs.