本帖最后由 td456 于 2010-4-14 12:28 编辑 : s$ w' i' K" } ; E/ ~& N; j: R1 oWe all know that if you want to change the rotation of a three phase AC motor.4 z1 X" W6 m9 ]" [- v ?2 {
Just swap any of the two phase leads.5 b1 c6 c( Q, d$ E+ |- _
But for VFD application you need to do the swap after the inverter. 8 @2 I# M) ~6 j- E7 ^: |; V$ tIf you swap the leads before the inverter, it will not work.
Yes, Good point. 8 s- O2 T" h5 G3 K0 l ; @- k2 q7 z/ `$ P$ EAs the principal of the VFD works, bascially from AC to DC, then DC to AC. ( F$ X5 L% i3 A/ W+ ?3 T& n
' }. F3 E& {3 N& W8 B4 NThe 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. 1 q- P' A% @6 Z8 V$ X2 [) g& `4 \9 U8 ]
The only thing you can change the rotation of the motor is the output side of the VFD, NOT the input of the VFD.