We have an application with a 10hp motor controlling a 10hp motor on which the VFD is protected on the line side by 20A fuses. There is an occurance happening where the motor load is getting jammed and is blowing the fuses on the VFD.
I would think that the VFD itself should trip in such an instance rather than blowing these fuses? I also belive that the NEC requires fuses protecting VFD's to be rated at 125% of VFD, in which case I would think that 20A fuses should be more than adequate for this drive, but maybe I'm wrong.
Should these fueses be blowing on extreme overload? Is there a setting in the drive that may not be correct? Do fuse sizes seem correct for drive?
I would think that the VFD itself should trip in such an instance rather than blowing these fuses? I also belive that the NEC requires fuses protecting VFD's to be rated at 125% of VFD, in which case I would think that 20A fuses should be more than adequate for this drive, but maybe I'm wrong.
Should these fueses be blowing on extreme overload? Is there a setting in the drive that may not be correct? Do fuse sizes seem correct for drive?