In article , Pavel314 wrote:
This is a theoretical electrical question, not something I actually
plan to do. Say somebody wants to run a new circuit from the breaker
box to one special outlet, like for a microwave oven or window air
conditioner or something like that. Being an ecconomical sort, this
guy decides that instead of buying the proper gauge wire for the job,
he'll use up some 14 gauge wire which is lying around from a previous
job, but run two hot lines and two ground lines

Hold it right there, cowboy.

If you don't know the difference between neutral and ground, you have no
business mucking about with 120VAC.

in parallel, as
diagrammed below.

Code violation. Conductors are not allowed to be run in parallel below a
certain size -- I think 2/0, but I'm not sure without looking it up.