A Tip on changing 3 phase AC motor rotation

td456

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$ e) N0 A/ i3 J) Z: q5 F( rWe all know that if you want to change the rotation of a three  phase AC motor.
Just swap any of the two phase leads.
% u- {- P8 o, F7 ^' l7 q: K/ qBut for VFD application you need to do the swap after the inverter.
# H' u0 M8 P- e! UIf you swap the leads before the inverter, it will not work.

nw123

go go go

MrElectrician

Yes, Good point.
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As the principal of the VFD works, bascially from AC to DC, then DC to AC.
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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.
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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.

jiodiangong

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