Wait, I never thought about that. Are you sure Norway has an IT system? 'cause that would contradict everything I learned at school. We heard an IT system only works as long there is _no_ ground connection anywhere, which is pretty hard to achieve with appliances like water pumps, water heaters,...
So my personal guess would be Norway is on a 230V 3ph network, the transformer secondary star point being grounded, but no neutral supplied.
