[jmr5x]

I have found tons of useful information on the site since I began working at an automotive manufacturer that produces engines. I could not find the answer to this question and wanted to post a brief description of what occurred at my plant.
Is there a correct way to trouble shoot a servo motor, amp, and encoder system that would pin point the correct failed component? We put a lot of parts on the thing and are still not sure in our trouble shooting even when looking back with all the data.
Any help would be much appreciated!
If this would get more response anywhere else on the web, please do let me know, thanks!

These are the faults that would repeatedly happen (s03, servo alarm NR 0050 2 overload) (Y20 Safety OBS Err 0008 0001 contactors welded) (s03 servo alarm nr 0052) Very strange noise growling or resonance and extremely high currents on the servo monitor screen.

Very loud resonance/ growling noise coming from a motor/ ball screw area of a horizontal tool changer.
The shift before me changed the amp and it ran for about 6 hours and faulted out for the same faults as before (s03, servo alarm NR 0050 2 overload) (Y20 Safety OBS Err 0008 0001 contactors welded) (s03 servo alarm nr 0052)
The noise would happen and the ball screw would stop moving but the noise would stay. You could NOT turn the ball screw by hand when this noise was happening and the current on the servo was over 500%. You would have to pull power to stop the noise.
As soon as power was cut, the ball screw turned freely.
Changed the motor out but did not have an encoder available so re used the original encoder (we did not make sure the orientation was correct)
Machine ran 6 hours
Machine then faulted out again but with NO noise for (s03, servo alarm NR 0050 2 overload) (Y20 Safety OBS Err 0008 0001 contactors welded) (s03 servo alarm nr 0052) had extremely high currents when ramping up speeds or changing directions
We then changed the encoder and made sure the orientation was correct.
Machine has been running for several shifts now with 130% current.

[underthetire]

First thing, buy a mega ohmer. Test cables and motors for shorts to ground with the mega ohmer. If that checks good, make sure servo rotates smoothly by hand, and check windings on servo with multi meter, to make sure they all read the same. All that is good, order a replacement drive.

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[jmr5x]

Thanks for the feedback underthetire! Do you have a method or source for directions on checking the cables and motor with the meg ohmer?

[bluegrasschips]

Cable assessment involves measuring the continuity of each wire in the cable from end to end, and then checking the resistance between each individual terminal and every other terminal to see if the wires within shorted to each other. You need to determine what the cable construction is prior though - ie is it straight through or more complex.

From there are you absolutely sure that it's not a mechanical issue? How does the unit behave if disconnected from the mechanical load?