Still not following you.
Skip the 80% load facture. Start by explaining; “How do you follow a circuit.”
Sorry for the edit: This product has been discontinued. Replaced by CT70 - GFCI and AC Circuit Analyzer
To further my explanation of your analyses, Represents 80% loading on the circuit, and as I requested, avoid NEC, Branch circuit conductors shall have an ampacity not less than the maximum load to be served [210.19(A)(1)]. *Note: The term continuous load is in more than one article in the NEC. Article 100. A load is where the maximum current is expected to continue for three hours or more.
So again I ask, for the sake of learning, how do you measure Vd along a lighting circuit?