480V VFD problem 2

[cherryg]

In one of our projects, we have a bunch of 480V VFDs in LV MCCs, which have not been used for the past 6 years. What are the steps required to ensure that these VFDs can be made operational? I understand that there are some issues regarding the DC capacitors. Please advise, if you have experience of a similar situation. Thanks.

 

[eletest]

In my opinion you can power up the VFDs with certain precautions. Capacitor replacement can come later.In any case, for the VFDs it is recommended to replace the capacitors after a period of around 7 years.
However before you power up ensure that the insides of the VFDs are thoroughly cleaned .Clear all residual dust or moisture inside . Otherwise some of the control cards are likely to fail. Also for the capacitors, initially you can raise the voltage gradually through a 3-phase variac.
There is no way to check whether the VFDs shall be operational or not without powering it up. Once it is powered up, if any problem persists, you would get to see the error codes and you'll have to act accordingly as per the OEM troubleshooting chart.