本帖最后由 td456 于 2010-4-14 12:28 编辑 : N8 @2 q7 z: F, [7 ?. A6 [6 U8 B5 x
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We all know that if you want to change the rotation of a three phase AC motor. - X& \7 Y9 s* i. qJust swap any of the two phase leads. & N# a. S# J. d& @+ K, B+ CBut for VFD application you need to do the swap after the inverter. : w: _5 y9 K) w3 B% AIf you swap the leads before the inverter, it will not work.
Yes, Good point. * w" a' p& ~5 X) P * ]) @! s4 R2 U' k9 R M! `+ u+ TAs the principal of the VFD works, bascially from AC to DC, then DC to AC. 6 |8 i" g% `3 c3 x5 p & _0 ]- M# k b. I6 a& B! F* q+ OThe phase rotation of the output of the VFD connecting to the motor is based on the sequence "open" or "close" controlled by the inverter pre-set inside; any changes to the phase rotation of the feeder will not affect the DC rotation, as DC is NO phase at all.8 [' q6 [5 j- B7 }' ]
* `/ D+ T' d D* F; CThe only thing you can change the rotation of the motor is the output side of the VFD, NOT the input of the VFD.