本帖最后由 td456 于 2010-4-14 12:28 编辑 8 ~7 |( w1 ^) X2 @( u: i0 F 8 Z l, O" `# G8 iWe all know that if you want to change the rotation of a three phase AC motor.* j/ p8 B8 x/ U- b; Q
Just swap any of the two phase leads.6 [3 x; w& U4 _: h
But for VFD application you need to do the swap after the inverter.3 C# o' ~5 F$ S
If you swap the leads before the inverter, it will not work.
Yes, Good point. 9 b2 T. b% w5 l " @7 ]5 @% I" Q3 ]5 G% Q3 ~As the principal of the VFD works, bascially from AC to DC, then DC to AC. $ D/ }3 Z5 Z5 e' [
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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. 0 b! `) z( _% _( F& L& h- ^" W" x8 t3 I6 e1 m& Y
The only thing you can change the rotation of the motor is the output side of the VFD, NOT the input of the VFD.