Re: [CAD_CAM_EDM_DRO] Re: 3 phase motor math

rainnea wrote:

>How important is it to match the VFD to the motor ?
>Can using a motor with a higher or lower inductance than the VFD is
>designed for cause damage to either ?
>
>

Yes. A motor with too little inductance can draw huge currents, and
may pop transistors in the VFD. As long as the inductance is within the
right range, the overcurrent safety circuits can respond in time. With
too low an inductance, the current can rise so fast the transistors get into
thermal runaway and secondary breakdown before the current sense
circuit can shut it off.

>I was hoping to use an old AC servo motor to power a spindle, so my
>main concern is if the VFD will spin the motor without blowing either.
>
>

Well, it depends. If the motor has current, voltage and HP ratings similar
to the VFD's ratings, it most likely will work.

Jon