Measuring amps off a Flex70

I never trust the clamp-on or C/T readings on the load side of the drive. In my experience, the keypad amp reading is the most reliable measurement.

milmat1 said:

Is this a drive that has been in service or a new install ?

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mister x said:

Old install where issue went away with replacement by other used unit. But now might be repeated on another old drive. Just trying to make sure current troubleshooting is sound, or as sound as possible.

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My experience does not include the powerflex 70 series, but I have some experience with other makes. I have noticed however that different series seem to have their own distinct failure modes. The 1333 series had a very similar erroneous current sensing failure similar to what you are seeing. The internally measured current would gradually increase in time. I attributed this to corrosion on the DC shunt causing a higher resistance, thus fooling the drive,

Due to the measuring errors that other folks have mentioned the method I used was to measure on a "sister" drive with the same equipment that I was using on the "problem drive". My presumption was that the same error would be present on both drives.