A Tip on changing 3 phase AC motor rotation

td456

We all know that if you want to change the rotation of a three  phase AC motor.
- X& \7 Y9 s* i. qJust swap any of the two phase leads.
& N# a. S# J. d& @+ K, B+ CBut for VFD application you need to do the swap after the inverter.
: w: _5 y9 K) w3 B% AIf you swap the leads before the inverter, it will not work.

nw123

go go go

MrElectrician

Yes, Good point.
* w" a' p& ~5 X) P
* ]) @! s4 R2 U' k9 R  M! `+ u+ TAs the principal of the VFD works, bascially from AC to DC, then DC to AC.
6 |8 i" g% `3 c3 x5 p
& _0 ]- M# k  b. I6 a& B! F* q+ OThe 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.

* `/ D+ T' d  D* F; CThe only thing you can change the rotation of the motor is the output side of the VFD, NOT the input of the VFD.

jiodiangong

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