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I tried to find explanation over this - maybe my terminology is wrong, couldn't find anything.

I wondered if it's important the for 3rd harmonic, intensity of voltage of Phase A is almost half the one of Phase B?

Also, if there is data about it on the Internet, I would need terminology to find it, since I couldn't find anything after 40 minutes.

This is a drive for a pump.

Here is a picture of the harmonics (each color is a different phase)

enter image description here

Mathias Boulé
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    for what device or power source? and what conditions or load – Tony Stewart EE75 Mar 18 '22 at 20:09
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    Mathias, perhaps provide a picture of what you are considering? A simple sentence isn't really cutting it for me. – jonk Mar 18 '22 at 20:17
  • @TonyStewartEE75 I added the information – Mathias Boulé Mar 21 '22 at 16:57
  • @jonk picture added!! – Mathias Boulé Mar 21 '22 at 16:57
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    @MathiasBoulé That doesn't look like half, to me. Just down a little. And even if I did agree that it looked like half, I still would have no context with which to understand anything about the system. I know it is a "pump." But there is a whole world of context missing here. I don't even know why you are "concerned" about your readings, yet. Is there something wrong happening that caused you to take these measurements? I don't mean to put down the picture. I'm glad you added it. It's just that I can't see how I can be of any help, yet. – jonk Mar 21 '22 at 17:50

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From my experience with soft magnetics in large transformers with very high permeability with CRGOS steel laminate, that over-voltage saturation will cause the significant rise in 5th harmonics in single phase. But this is 3 phase and imbalanced currents might also correlate with excess vibration and partial saturation of some phases will reduce the inductance and increase the relative harmonics.

We have no idea what type of motor this is, the ratings, tolerances, load factor or the quality of the voltage source or commutation or even what components are used. So if you want better advise, please offer a better question with details.

Tony Stewart EE75
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