; Y$ \ f; h: W5 s* S& h6 CWe all know that if you want to change the rotation of a three phase AC motor. + x9 o6 O5 G' k3 @: oJust swap any of the two phase leads.7 k$ `& J; ]8 ~, Y
But for VFD application you need to do the swap after the inverter.3 w, O; b& n9 x/ i
If you swap the leads before the inverter, it will not work.
Yes, Good point. ; ^: u8 H1 Q4 n0 X1 R- n ( ^" P9 b" L3 y8 eAs the principal of the VFD works, bascially from AC to DC, then DC to AC. 9 i; @2 |) i; b% `: `; Z
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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 n/ x- p L5 J& e2 w) ~+ K) V / `& t4 m4 L6 R# Y6 d4 xThe only thing you can change the rotation of the motor is the output side of the VFD, NOT the input of the VFD.