ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Are European neutrals multigrounded?

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.

@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.

@Trumbaschl,

I don't see why not. The live conductors are never connected to the protective earth. Sure, it will leak everywhere and probably like Wolfgang says trip the RCD. But it could still be IT'ish.

We have isolated IT supplies for shaver outlets in British bathrooms. In that case though, we're only talking about a short system: The transformer is normally right behind the plate on the outlet itself and feeding only a few feet of cord and the shaver. The opportunitites for both resistive and capacitive coupling to earth are rather minimal.

Yeah, and that's what I was thinking about. According to Austrian code IT is limited to small local systems fed off their independent transformer of generator.
Shaver outlets have been around here too, I think standard sockets in bathrooms are allowed since the mid 1970ies or even 80ies. Many old shaver outlets can still be found.