how determine load wire on AC line

[Knobhead]

Your question was a bit unclear, so sorry if I answer what you have not asked =-)

On a 3 phase system (all normal trickery is generated 3 phase) if there is even load on the 3 phases the net neutral current will be zero.
So at the transformer, if the system is designed in balance there is no need for an expensive copper run back to the power station.
However as the balance is slightly off in practice they need to 'dump' the extra electricity, so the send it to ground.

So it is more that the N is earthed at the transformer, not the other way around.

So in your house (when everything is working well) you will have the same amount of trickery coming out of the N as comes in the L, and nothing going down the earth.
At the transformer there will be lots coming in and out of the lives, and a small amount in the N which gets dumped to ground.
Although there is a small amount of trickery in the N it will not go back up the E as the path of least resistance is too ground.

If you have an RCD in your house that 'measures' the amount of trickery coming in the L and subtracts the stuff going out of the N, if there is a net then it cuts the supply (as it means some it going out of earth).
If you had no earth, there would not be an imbalance and RCD would not work until an earth was introduced (eg you touching the faulty item and acting as an earth).

This is embarrassingly simplified, but I hope it gives a better understanding.

I just don’t know what to say, either you’re drunk or smoking something you shouldn’t.
Danieru, please ignore the above post, it’s utter rubbish.

 

[Inteificio]

I just don’t know what to say, either you’re drunk or smoking something you shouldn’t.
Danieru, please ignore the above post, it’s utter rubbish.

It is a gross oversimplification, that will unsurprisingly not fit with your understanding of 'correct'.
Most gross oversimplifications are false by definition.

However they can give a sort of understanding to someone who is not trained in the area.


He is not wanting a 3 day description of what is precisely happening with all the formulae, but that seemed OK.

Sorry it did not meet your exacting standards.

 

[Engineer54]

Within your house the neutral and earth must be separate wires, outside your house (back at the suppliers transformer) they are joined.

To supply the radiator you need Line1, Line2 and earth.

To supply sockets and other single phase appliances you need a single Line, Neutral and earth (though the earth may be omitted in some unsafe cases)

This diagram shows a depiction of how the wiring is arranged, this is just to show the principle not an actual layout.
View attachment 12463

Not absolutely sure here, but have a feeling that Sweden has in some regions, single phase 3 wire systems, similar to the Yank distribution system!! Still think it best for the OP to contact a local electrician to convert one of those phase lines to a neutral at the DB and the accessory plate changed. That'll give him the general purpose socket outlet that he wants....

 

[Knobhead]

Based on the figures our OP has given it is two legs of a three phase system. I will say my first thoughts were a singe phase centre tapped set up.