@Ranger
This is an issue I have never completely understood so far:
Not only completely ungrounded, but also systems grounded by means of an high earthing impedance (?) are called IT-systems. But in cooperation with cable capacities will result a sufficient earth fault current to trigger a standard RCD, in case of a fault. Something which is a completely different approach compared with the ungrounded local IT-systems you'll find in a hospital or delicate manufacturing industry. Here a permanent insulation check is required.
But yes, Norway is supposed to have in majority IT 3 x 230, look for instance at special surge products by phoenixcontact for this Norvegian system. And it is reported that quite a lot of French rural LV distribution is made up in a similar way, so being rather IT than TT, but working similar. Furthermore the Norvegian system seems to have French roots.
