# How to calculate the neutral wire size of a home (department)?

I know that in electrical grid, Neutral wire is a non current carrying conductors so its cross section area is smaller than the cross section area of the live conductors. I think it has half of size of the live conductor.

Is this rule valid for a department or a small home that uses 1 phase only? If I'm buying the neutral cable for a home, Should it be less that or equal live wire ?

My country does not have grounding system. The wall outlets have two ports only (220V / 50Hz). But the neutral of distribution transformers is grounded.

Thank you,

• In a properly wired arrangement, the neutral conductor will carry exactly the same current as the live conductor. – EM Fields Feb 29 '16 at 17:23
• For single phase, the return current is carried by the neutral. You need equal size conductors. Half- or third-sized neutral applies only to three phase. – uint128_t Feb 29 '16 at 17:25
• @uint128_t Unless of course every home appliance comes with a 15m copper rod to hammer into the ground. :-P Jeez, would I hate having a tile floor in that system! – Asmyldof Feb 29 '16 at 18:46