Answer / ramendra shukla

If the cross sectional area of three phase(R,Y,B) &Neutral
are -

Cross sectional Area of Conductor,R = Cross sectional Area
of Conductor,Y = Cross sectional area of B; but the Neutral
size is half of phase then it is 3.5 Core.

And when -

Size(cross sectional area of Conductors R,Y,B & Neutral are
same then it is know as 4 core.

Answer / k.prakashchandra

If the currents in all phases are equal ,the current in
neutral is zero.Hence if the currents are almost balanced
the size of neutral conductor can be reduced to 50 % in
view of economy

what is diffrential relay used in generator plz give brief explanation

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I do wonder why current is present in neutral wire?i check single phase lead current feeding air conditioner...on its phase its current was 10A while same was 10A in neutral...as we know in neutral voltage is zero so if voltage is zero then how current appears on amp meter? my second observation is (just imagination)when I touch phase wire it give me shock but when i touch neutral nothing happens although as above its carrying current(amps) third but with same logic...as in simple Alternate current sine curve there is + and there is negative peak.means every time phase changing so how come every time same phase and same neutral stand (pardon for english mistakes)

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