, and then there is no advantage of 12-2-2
over 12-3. In fact 12-3 is better because it reduces the voltage drop.


It does what?

Just what he said it does. A multi wire branch circuit will operate all
but the imbalanced portion of it's load at 208, 240, 480, or what have
you rather than at 120, or 277. Using a single phase multi wire branch
circuit supplied from a single phase 120/240 volt center tapped service
with twelve amps on one leg and fifteen amperes on the other the neutral
will only carry the difference or in this case three amperes. On a
circuit that is fifty feet long the three amperes has a voltage drop of
the round trip distance of one hundred feet the twelve remaining amperes
from both legs will have the voltage drop of only fifty feet because it
is using the other ungrounded conductors load to complete the trip. You
get the same amount of work done for roughly half of the voltage drop.
--
Tom Horne