ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Norwegian power?

Thanks! Id be very interested in the windings and data plate.

If you zoom on this picture: http://commons.wikimedia.org/wiki/File:Three-phase_distribution_transformator_IMG_8086_Hurum_Norway_23kV_240V.JPG

The data plate says Yyn0.

Which would come out as ungrounded wye primary with a wye secondary neutral brought out.

Now that I think about it, if the primary is wound wye, wouldn't it be so it can be solidly grounded? What would the IEC designation be for that?

I see what looks like a forth ground/neutral wire on the MV, so it would make sense then.

A primary grounded wye has the advantage of being resistant to ferroresonance, which Id imagine is more of a concern at 22kv and a long run.

Unless the primary is ungrounded wye? If ungrounded, than why wye and not delta? An ungrounded wye with a shorted secondary nullpunkt and one 230 volt phase faulted would make for some very interesting conditions.

Very interesting.