You missed a spot in math. After removing parenthesis, you arrive back at p-g = p-gwhy phase-ground voltage = phase-neutral + ground-neutral Voltage ?
Shouldn't that be like this?
phase-ground = phase-neutral + neutral-ground
Just write it mathematically:
(p - g) = (p - n) + (n - g)
Then remove the parenthesis...
p - g = p - n + n- g
...and re-arrange the terms...
p - g = p - g + n - n
If we are talking about power distribution, such as to a receptacle, then ground should always be zero volts, assuming no faults, since it is there only as a safety, not a normal current path. That is the job of the neutral line. True, both wires may tie to the same buss bar in the distribution box but that same bar should, by code, be tied to a driven ground rod, therefore zero volts.The original question, I assumed, (yes, we know what that means),was that measurements were taken at the load point.Note: V(ground) may not be zero