Why Harmonics in a three phase motor ? 2

[COMAPRO]

recently I measured the electrical parameters of a 50 HP motor that has a wye delta starter , no electronic at all and my Fluke power meter registered 60% THD-R, Why ?
Thanks in advance for any tip you can tell me on the subject

 

[edison123]

COMAPRO

If your capacitor is connected at the motor terminals, could you disconnect it and then check your current again ?

 

[electricpete]

I'm sorry, I misread your first post and thought you had unbalance.

The only influence of the capacitors that I know can be to increase the (fundamental) voltage. Higher voltage pushes further into saturation and causes more current harmonics.

 

[edison123]

pete,

that was exactly I was thinking.

 

[COMAPRO]

Thank you electricpete for the tip . the motor belongs to a customer of mine . I will se if he wants to disconnect the capacitors. Remember that they are there to improve power factor. Lets say that the current harmonics decreases without the capacitors but he would be penalized because of low power factor