Powerflex 70 / HW OverCurrent Fault #12 - What is the common reason for this fault ?

Good Afternoon ,

I have a Powerflex 70 Drive . It faulted out with a #12 HW OverCurrent Fault .

With your experience , what is the common cause of this fault ?

Thanks so much .

That means the output current of the drive exceeded the limit. If it's been running fine for a while and then started faulting, I would first check the load. If possible, de-couple the motor and see if the motor bearings ok and if there's any mechanical wear or binding in the driven load.

Have had this same fault caused by loose/bad wiring, bad motor & bad remote disconnect. As I recall, HW Overcurrent means the drive is seeing 2.5x the motor nameplate current.

The F12 Hardware Overcurrent is an "instantaneous overcurrent" protection feature built into the transistor section of the drive, rather than analyzed by the firmware running on the main control board.

Typically it means the drive is observing 220 to 300 % of the output current rating of the drive itself; the percentage depends on the frame style.

The most common reason for that fault is a wiring or motor failure that is turning a lot of current into heat.

But there are other reasons, which can include motor selection and basic drive configuration. Which is the most likely can, of course, depend on where you are in the drive's application lifecycle.

The RA Knowledgebase has a good general troubleshooting guide for F12 HW Overcurrent (Access Level: Everyone).

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/107475/loc/en_US

Separate the motor and check if the motor bearing is normal

F12 fault

To be more clear, the most common cause of this fault is a shorted wire (L1 L2 L3/UVW inside the pecker head. What I do is set auto retries (A092) to 9 and watch for the phase loss fault to show, (F41/F42/F43). I’ll bet it’ll be right there when you open the pecker head. Sometimes you’ll have to look beneath where the wires go inside the shell of the motor, but it’s there.