This on is a little off topic but here goes.
Got a call at 5 this morning to check a problem with an SEW servo. It was an old Movidyne drive and if it was fixable, it was too late since the first electrician on the scene damaged it while trouble shooting.
Had a new Movidrive as a spare, so decided to swap it over. After a little problem with the resolver caused by pin 6 and pin 9 being reversed (upside down 69 is still 69), got it running around 12:30.
Now this is the problem, at zero speed it was drawing around 30 to 50% current, the motor was getting hot and the unit was tripping out on 'Protection Fault'.
Try as i might, I couldn't get the current down. It didn't appear to be any of the parameters for the PI controller, or the hold controller. It was a conveyor positioning system, so it wasn't holding a load. The set point was only a few increments from the actual position. Changing the gain, intergral, feed forward had no effects.
Eventually, I added an 'inhibit mode' bit to allow the motor to rest when it was not in operation. This resulted in it cooling down to tolerable levels. This was enough for me to go home and get some rest. I will be having a second crack at it on Tuesday, unless it falls over between now and then.
If anyone has any ideas on what could be wrong, I would be most appreciative.
The only thing I havn't tried yet is replacing the motor.
Doug
Got a call at 5 this morning to check a problem with an SEW servo. It was an old Movidyne drive and if it was fixable, it was too late since the first electrician on the scene damaged it while trouble shooting.
Had a new Movidrive as a spare, so decided to swap it over. After a little problem with the resolver caused by pin 6 and pin 9 being reversed (upside down 69 is still 69), got it running around 12:30.
Now this is the problem, at zero speed it was drawing around 30 to 50% current, the motor was getting hot and the unit was tripping out on 'Protection Fault'.
Try as i might, I couldn't get the current down. It didn't appear to be any of the parameters for the PI controller, or the hold controller. It was a conveyor positioning system, so it wasn't holding a load. The set point was only a few increments from the actual position. Changing the gain, intergral, feed forward had no effects.
Eventually, I added an 'inhibit mode' bit to allow the motor to rest when it was not in operation. This resulted in it cooling down to tolerable levels. This was enough for me to go home and get some rest. I will be having a second crack at it on Tuesday, unless it falls over between now and then.
If anyone has any ideas on what could be wrong, I would be most appreciative.
The only thing I havn't tried yet is replacing the motor.
Doug