On Sun, 27 Dec 2020 09:57:54 -0500, Ralph Mowery
wrote:

In article ,
says...

The magnetic field of the hot and neutral cancel each other. Otherwise
steel conduit wouldn't be usefull.

I agree with Ralph, high current with wire wrapped can overheat the cord.
You are correct with a pure resistive load but with a capacitive or
inductive load (high power factor) if I remeber correctly there is a
reluctance issue



I doubt that the metal would be much of a factor if any. I worked in a
plant that had miles and miles of wiring in conduit. Much of it
powering large motors.

Some installer did make a major mistake on one wiring job. On a 3 phase
circuit he ran two wires in one piece of conduit that was about 5 feet
long and the third wire in another piece. Did not take long for those
wires to over heat and melt out some plastic terminal strips.


The interaction seems to show up as capacitive coupling on the
grounding conductor be it a metal raceway system or in a grounding
wire. It is not important until you install GFCI protection.

*********

"The circuit is too long for the equipment being protected by the
GFCI.

This is common in GFCI circuit breakers with circuit lengths over
150. Capacitive leakages due to the wire length of the circuitry may
exceed the threshold of the GFCI. (The actual length limitations vary
depending on wire type and size.) To prevent this issue, place the
GFCI device close to the equipment it will be protecting €“ this may
mean using a GFCI receptacle or blank face GFCI device near a normal
receptacle."

https://www.hendersonengineers.com/i...fci-nuisances/