Regenerative Overvoltage Trip During Constant Speed

[BuffaloB219 0]

I have a Mitsubishi 740-120 VFD. I am using it to move a conveyor with a load up and down. When the load reaches roughly 2000 pounds the VFD will trip out and signal an error message. E.0V2 which is "Regenerative overvoltage trip during constant speed" VFD and motor has been changed and brake has been adjusted on the motor but the problem keeps occurring. What would be a reason(s) that this would keep occurring and what else could be checked out? Thanks for the help.

[Chris Elston 79]

Do you have a regen or a braking resister attached to this VFD?

[kaare_t 155]

Correct! Regenerative means that the motor suddenly acts like a generator sending back to the inverter and the inverter cannot handle the incoming current. You need to set up an external brake resistor connected to the inverter and set up the inverter to "burn off" regenerative current.

[drforsythe 15]

Check for a good ground for the vfd supply and make sure the motor is grounded at the vfd ground connection. I have seen this before. I have even seen a drive show this fault when the motor was not commanded to move and the motor de-energized. The drives are set up to protect both the motor and vfd. Sometimes this sensitivity can lead to nuisance faults. I don't guarantee this is the problem, but I have seen this problem disappear after ensuring good grounding practices were used. Good luck, Derek

[BuffaloB219 0]

The customer forgot to mention they had a Brake Resistor connected to the VFD. I had them measure the ohms and it was 14ohms on a 75ohm brake resistor. They will be replacing the brake resistor. Thanks for the help everyone!