Following on from the previous vector explanation tools we can use this approach with 3 vectors representing 3 currents at 120° to each other.
By dragging the arrowheads of the three vectors red, green and blue alter the lengths outwards from the centre point then slide the redraw vectors slider to reveal the resulting vector which represents the current in neutral.
Try a few combinations of differing current combinations and one where they are all identical and note how when they are similar in magnitude the neutral line is relatively short and when they are all equal the neutral line disappears meaning that no current flows in the neutral.
This demonstrates visually a concept which can be calculated by a number of methods (scale drawing, trigonometry, even rect and polar co-ordinates).
