本帖最后由 td456 于 2010-4-14 12:28 编辑 6 L( X* |2 j2 ~6 C- b/ c, v7 b! J+ Y! d$ E/ E% n
We all know that if you want to change the rotation of a three phase AC motor. 6 L0 H6 j: Q, _. T3 \% GJust swap any of the two phase leads. . e; E- U# z, f% k0 RBut for VFD application you need to do the swap after the inverter. _) H0 u9 ] ]+ o
If you swap the leads before the inverter, it will not work.
Yes, Good point.! l- E& Q: m9 k
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As the principal of the VFD works, bascially from AC to DC, then DC to AC. . Y6 a( \) U# I- \
; F( d) Y' W8 x1 d" P* k7 I; \% v% xThe 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. ' V( Z7 t6 Q% C3 D+ \5 F- e* {0 E2 s4 l6 ~( u- ?
The only thing you can change the rotation of the motor is the output side of the VFD, NOT the input of the VFD.