Capacitors play a major role in our Variable frequency drives (VFD), keeping them up-to-date and working properly can save us from major headaches down the line.
High temperatures, humidity, duty cycle and shelf time can attribute to the life span and performance of a capacitor bank. As a proactive and preventive measure evaluating the VFDs capacitors can prevent undesired downtime and permanent damage to the drive, resulting in costly repairs.
The most common mistake practices in today’s industry on replacing capacitor banks are: “Waiting until if fails”, going based on manufactures date code (not considering self-time), Operational hours and deformities or signs of leakage.
By evaluating your VFDs capacitor’s ESR (Equivalent Series Resistance) we can determine if it’s over or under the specific resistance value. Higher resistance may cause higher frequency noise, higher operating temperature, decreasing filter effectiveness and increasing ripple affecting stability of a control loop application. So let’s make sure we keep our “Caps” in order to prevent any major blow outs.