本帖最后由 td456 于 2010-4-14 12:28 编辑 4 X2 u# s) o2 T( l- K; I5 x" y+ D' b& c8 i% T! L
We all know that if you want to change the rotation of a three phase AC motor. . \& E1 ^; e1 @- cJust swap any of the two phase leads. E; V K6 f4 y2 G" m n8 R' {) I
But for VFD application you need to do the swap after the inverter. b% H9 b/ B2 G: p- t6 nIf you swap the leads before the inverter, it will not work.
Yes, Good point. & P) b* x2 m9 V- K* ^4 k : W# w& s( v' k3 D$ O" Y$ U9 JAs the principal of the VFD works, bascially from AC to DC, then DC to AC. 3 O e' G* l$ q$ D3 [0 C8 r
$ g- z- J9 L4 e. f% @+ b1 cThe 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.4 d& _/ H+ |/ s6 g
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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.