Does anybody have a wye-wye connection diagram for a step up transformer. The transformer is fed 208V and the secondary feds a panel at 480V. It would be great if the diagram also shows the grounding and bonding connections.
Thanks in advance!

 
If 480Y/277V service is needed, the most common transformer configuration will have a 208V-delta winding, served by a 208V 3ø 3-wire source — a neutral conductor is not used.

See “Group A” units at www.acmepowerdist.com/pdf/Page%2014.pdf

See connection 46 at www.acmepowerdist.com/pdf/Page%2055-63.pdf

Grounding of the HO terminal is the same as for other separately-derived systems, such as the more common 480-delta—208Y/120V unit.

Low-voltage wye—wye transformers can have problems with triplen-harmonic currents, so are not too common and should be carefully applied.




[This message has been edited by Bjarney (edited 11-10-2004).]

Thanks for the info! Does anyone have a drawing for a wyw-wye transformer?As per my post.

I found this thread in the "technical reference" area of this forum. If this isn't what you're looking for, you might search there.

https://www.electrical-contractor.net/ubb/Forum15/HTML/000065.html