Value of Impedance test on Rebuilt D.C. motors

[dyno40]

I would like to invite comments on the value of measuring impedance on rebuilt D.C. motors. I find that the impedance value of newly manufactured coil varies substantially compared to original coils. This is due to the coil manufacturing process. Although the motors pass all other statis & running test and stay within parameters, the impedance value has deminished on newly manufactured coils.
I can develop new specifications for the new coils but at this point I question the value of doing the test in the first place.

Can anyone comment?
Thanks

 

[light1]

Probably, coils are not wound as accurately as by the OEM. Also, conductor and insulation parameters can be noticeably off.