Maybe I miss the right way to post this..
from mine experience and from the previous post, I understood, that VD (voltage drop) seems to be quietly "ununderstandable" in terms of calculation origin.
With a simple test based on 2 identical panels (230V), I found the reason that the cable setting (Ampere, dimension, diameter, used in calculation) represents the most important scenery to be taken into consideration.
Unfortunately, by the preset cable (revit 2014 default file, USA standard, es. THWN), the drop voltage has a sense, but by simple personalized cable, there is no way out to figure with drop voltage calculation different from zero.
What's gonna be the wrong/mistake/error?
waiting your response, I thank you.