本帖最后由 td456 于 2010-4-14 12:28 编辑 , Z3 L$ d- Z3 M }* C: F! n ) h2 x+ J9 z6 r8 yWe all know that if you want to change the rotation of a three phase AC motor. : Y- }& G$ D/ u6 ~" SJust swap any of the two phase leads.+ H* b- j% z. N) b
But for VFD application you need to do the swap after the inverter. 5 M5 L4 `" o! a8 h5 E% NIf you swap the leads before the inverter, it will not work.
/ @& C. x6 Q5 C2 t0 R( `As the principal of the VFD works, bascially from AC to DC, then DC to AC. : j. J) e |+ r/ T+ O- c7 O$ w- [0 c5 G3 y7 V. ]5 d k
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.( c2 F) V: N" ?+ @; E2 j
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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.