本帖最后由 td456 于 2010-4-14 12:28 编辑 8 c3 G* \8 G+ f1 g' G: \$ u3 k; J
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We all know that if you want to change the rotation of a three phase AC motor.# a5 t# W M. {" R- x
Just swap any of the two phase leads. " d! B4 V" S) w+ l' I8 \But for VFD application you need to do the swap after the inverter. . R2 ?3 p5 ^+ N6 ZIf you swap the leads before the inverter, it will not work.
Yes, Good point.5 s% |( ]( P& k' @* V6 U) v
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As the principal of the VFD works, bascially from AC to DC, then DC to AC. : f; i5 w% P% [# x Q+ P1 @
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The 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.* L0 m' v3 X4 y2 O% H2 ?
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The only thing you can change the rotation of the motor is the output side of the VFD, NOT the input of the VFD.