Don Fearn wrote:
I think it was Nate Nagel who stated:


You do not want to pull more than one cable through a hole;
theoretically the currents in any given cable sum to zero but if you are
pulling a LOT of current and there's a cable smack up against another
one, you could get some induced voltages.

True, in theory. And in practice in some places, homes not being one
of them for typical home wiring, which is, I believe, what the OP is
talking about.

The amount of induced voltage in home installations is irrelevant and
can be ignored, as evidenced by MANY power cables sharing MANY holes
with impunity in every home I've ever lived in.
--
"Trust me, there is NO way to nonchalantly conceal the fact that you have a
power tool in your head, no matter what you do." -- El Gato


That's for sure. If just having one AC cable next to another was a
problem, there would be a lot of screwed up houses, including new
constructions. Any induced voltage is going to be so small that it's
nothing compared to the fluctuations caused by normal powerline
transients, turning on/off large loads, etc.