Phasor rotation

[AggiesNM]

Hello fellow engineers,

I need help with something basic.
If the phasors are rotating ABC counterclockwise. Is it possible to change this to ACB through a transformer? In other words, can the phasor rotation be changed at the transformer?

Thanks

 

[jghrist]

You can change the rotation of the secondary cable connected to the transformer by connecting them to different secondary terminals. For instance, if the primary is ABC counterclockwise and is connected to primary terminals A-H1, B-H2, C-H3 (using North American terminology), the phase rotation of the secondary terminals X1, X2, X3 will be X1-X2-X3 counterclockwise. If you connect secondary phases a,b,c to a-X1, c-X2, b-X3, then the secondary phase rotation will be a-c-b counterclockwise.

 

[HamburgerHelper]

You can fix phase rotation but you still have to get the phase angles correct on the secondary side if you might be fed from multiple sources or swap over loads. Transformer connections must have the correct rotation and angles. Most utilities have a +/- 30 degree connection between the high side and low side terminals of a transformer.

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If you can't explain it to a six year old, you don't understand it yourself.

 

[AggiesNM]

Noted. Thank you.