Earthing neutral

But how would current flow if there are no line to neutral connected loads?

You can connect single phase loads between any two different lines if you wish - they don't have to be connected L-N - that's just a usual convention. In the HV distribution world (in the UK at least) everything is connected between lines - N is never distributed. Because the three lines are out of phase with each other there's always an a.c. voltage difference between them. Almost all 3-phase loads are electrically just single phase loads internally (e.g. individual windings on a 3-phase are just a simple coil with one wire at each end)- even if they're mechanically linked.


You just need to be careful about voltage ratings - if you have a 230/400V 3-phase system then single phase loads connected between lines will see 400V rather than 230V - so equipment would be need to be suitably rated. Or you could have a 3-phase system with 230V between lines (so each line would be about 132V from Earth or N).


    - Andy.

But how would current flow if there are no line to neutral connected loads?

You can connect single phase loads between any two different lines if you wish - they don't have to be connected L-N - that's just a usual convention. In the HV distribution world (in the UK at least) everything is connected between lines - N is never distributed. Because the three lines are out of phase with each other there's always an a.c. voltage difference between them. Almost all 3-phase loads are electrically just single phase loads internally (e.g. individual windings on a 3-phase are just a simple coil with one wire at each end)- even if they're mechanically linked.


You just need to be careful about voltage ratings - if you have a 230/400V 3-phase system then single phase loads connected between lines will see 400V rather than 230V - so equipment would be need to be suitably rated. Or you could have a 3-phase system with 230V between lines (so each line would be about 132V from Earth or N).


    - Andy.