Re: Line vs. Load
I vew the terms Line and Load as being applicable to a specific component. There is no line versus load concept in the wiring system viewed as a whole.
For example, there is a line side of a disconnect and a load side of the same disconnect. If you have several disconnects in line (series), then you can say the same about each in its turn. If you have several disconnects in parallel, then you could say they have a common line side, and individual load sides. Or you could still look at each as having its own line side and its own load side.
Is this what you are asking?