text: <s>[INST] Powerflex 40P Summary: motor burning up On a new conveyor line at the factory where I've been working a motor powered by a Powerflex 40P keeps burning out. I'm no motor expert but from what I can tell looking at the windings, I suspect that the motors have been subject to single phasing. The reports on the motor are that it will be running fine and suddenly heat up, smoke and die. I suspect a bad wire in the motor branch circuit or a loose connection between the drive and the motor - the disconnect was replaced thinking it might be a bad disconnect switch contact but it didn't solve the problem. I;m wondering if there is any fault that should occur on the drive quickly upon a single phase condition. I'd expect the overload fault to occur from the increased current on the remaining phases but I don't know for sure. I know that there are phase to ground and phase to phase short faults but what if it is a broken wire in the circuit? Thanks in advance for any comments, David Butler [/INST] What is the cable distance between the PF40P and the motor? If it is more than 40 feet, you may be experiencing reflective wave that will punch holes in the insulation of the motor and cause it to fail. It all depends on the insulation quality of the motor you are using. A motor that is rated for inverter duty that meets NEMA MG1 part 31 would provide protection from this problem. There are also output reactors or filters available to help in the situation. \\n </s>