Edm Issues

[Dinge]

Hi all, first post so please forgive any muckups.

 

Any one have experience with SKF's TKED1 EDM bearing spark discharge detector.

I've tried one on a 400KW Pope motor with known EDM issues and found the detector was indicating a lot of activity (hits) at the DE and NDE ends. Was also picking up and registering hits from the motor cable and surrounding metalwork - so a bit confuesed as to how useful it will be.

[yuri]

Hello.

Is (only) one end bearing on the motor insulated? Then maybe the insulation is broken?

[marke]

Hello Dinge

 

Welcome to the forum.

 

The device is designed to pick up transient EMI pulses that are generated by a discharge in the bearings. It will also pick up the switching transients from the VFD is held close to the cables etc.

Have a look at http://www.eng-tips.com/viewthread.cfm?qid=231381

Best regards,

Mark.

[Dinge]

Thanks Yuri and Mark, the detector is senitive in the frequency range 50 to 200Mhz so I agree that it would pick up switching components from the cables. Problem is these radiated components seem to be coupling into the motor and creating false positives or masking the actual phenomena (discharge event) we are trying to detect.