The article of NFPA79 clearly state the following:
13.5.2 Percentage fills of Raceways (Ducts)
"The combined cross-sectional area of all conductors and cables shall not exceed 50% of the interior cross-sectional area of the raceway (duct). The fill provisions shall be based on the actual dimensions of the conductors or cables used".
My concern is the 50% filling include the space between conductors or only the cross section area of the conductors?
This filling concern only the metal wire way, how about the plastic one?