Our system voltage is 380/220, 3phase 4wire. If I have a load of purely 220 single phase connected to L-N on a distribution panel 380/220 with solid neutral, do I have to increase the size of the neutral wire of the feeder?

<Moved from Electrical Engineering and fixed spelling of neutral - KISS>

The size of the conductors is determined by the load (amps) the conductor is expected.

Without knowing the amperage needed, whether the load is a continuous "ON" or not and the distance it needs to be run, we would all be guessing.

Please supply the necessary information.

our system voltage is 380/220, 3phase 4wire. if i have a load of purely 220 single phase connected to L-N on a distribution panel 380/220 with solid neutral, do i have to increase the size of the neutral wire of the feeder?

<Moved from Electrical Engineering and fixed spelling of neutral - KISS>

What you need to do is have a qualified electrician do this installation for you.

If you have to come to a "Home & Garden" DIY board to ask this then you are obviously not qualified to do this work.

Sorry for speaking the truth.

I also assume you are not in the US.

What you need to do is have a qualified electrician do this installation for you.

If you have to come to a "Home & Garden" DIY board to ask this then you are obviously not qualified to do this work.

Sorry for speaking the truth.

I also assume you are not in the US.

You don't seems to understand the question ask... technically if load are balance in a 3phase system the current in the neural is zero amps... if the load is purely L-N there is a tendency that unbalance current may occurs.. bigger current migth flow to the neural wire..

you dont seems to understand the question ask... technically if load are balance in a 3phase system the current in the neural is zero amps... if the load is purely L-N there is a tendency that unbalance current may occurs.. bigger current migth flow to the neural wire..
Oh, I understand perfectly.

What you don't seem to understand is that if you have to come here to ask this then you are not qualified to do the job. I suggest you go to a superior and get this information? Surely there is someone in your company that knows what they are doing.

I don't care what country you are in. Maybe this is why third world countries have such messed up electrical systems.