Schneider VFD Issue

Hi all, I am using Schneider VFD ATV312HU55N4 in my system, which will provide 5.5 kW for my motor.

I have tried using the system in two different places, once a 440 VAC and the other time 380 VAC. There was no issues with the VFD or whatsoever.

However this time, I am using at another place which provides 415 VAC. But when we try to start the system, the VFD displayed an error on its panel, "OSF", meaning line supply over-voltage. We couldn't understand why, and the VFD finally emit some smoke and we stopped using it.

We changed a new VFD, and on the first starting of the system, the same error, "OSF" displayed again. And then some smoke emitted.

We then removed the VFD, and checked the voltage at the voltage input terminals with multimeter. It is indeed 415V.

Hence, I hope anyone can provide any insights into this problem. Is the voltage supplied the main culprit?

Thanks.

But did you check the voltage from each phase to ground? The three phase power may be corner-grounded (one phase grounded) or it may be floating at some unacceptable voltage to ground (the whole network floating). Check in the drive manual for how to deal with unbalanced or floating power networks. You may need to disconnect some CE noise suppression filters.

thanks dickdv.

just checked with oscilloscope. realised its producing pulse waveform output instead of sinusoidal type. no wonder...