Changing the rated voltage of a VFD driven motor 2

[edison123]

A 220 V, 150 HP, 50 Hz, 375 RPM motor is being driven by a 440 V VFD. The motor has failed and I want to redesign and rewind the stator winding for 440 V operation. My reasoning is that the old arrangement, you would be seeing lot of harmonics (440 V VFD delivering 220 V). With the new voltage of 440 V, the output will see much less harmonics.

Do you, drive experts, see any problem with this idea ? I somehow got a nagging feeling about V/Hz issue but just could not pinpoint it.

 

[jraef]

If you are not needing to run in Open Loop Vector mode, you may not even need to have the drive tuned to the motor at all.

It's been a while since I programmed an ATV71, but I still have my manuals etc. I'll check to see if they show any details.

 

[edison123]

Jeff,

The client wants to run the motor at 160 RPM with the 415 V, 300 RPM winding (since the voltage is maxed out at 415 V for 150 RPM connection, he cannot go up to 160 RPM).

He also would like to have more torque at 160 RPM (it is a sort of vertical turning lathe). Can I advise him to increase the V/Hz from 415/50 to 440/60 so that he can get a higher voltage and torque at 160 RPM ?

* I would go green if only I were not yellow *