3 Phase 4 wire

[lloydy304]

Hi, quick question about 3 phase 4 wire systems.

If I was wiring a single TP+N board all circuits running 230v very and well balanced and had a max load of 234A / 3 = 78A per phase.

So removing all correction factors and sizing the connection tails a wire size of 16mm br/bl/gr/bl should be sufficient?
The main question is can the neutral wire also be 16mm as the loads are balanced and neural should be zero current?

 

[snowhead]

Even if the phases aren't balanced the Neutral only needs to be the same size as the phase conductors.

 

[pc1966]

It also depends on the sort of load. If you have non-linear loads like computer power supplies they result in harmonic currents and the 3rd harmonic in particular is trouble as it adds at the neutral, not cancels. But it would be quite extraordinarily bad to need a neutral above the phase size!