On Mon, 25 Jan 2010 11:58:59 -0800 (PST), Half-Nutz
wrote:

On Jan 23, 1:54*pm, Ned Simmons wrote:
On Fri, 22 Jan 2010 20:19:46 -0500, Wes wrote:
Bruce,

The Brits use a scheme when a branch circuit starts and ends in a breaker panel. *In other
words, you feed a branch loop from both ends. *This has the effect of doubling the wiring
feeding a device.

I've wired my recepts with 12ga which sucks compared to 14ga. *I asked my brother that is
in the trade why 14 is popular and he told me it is because it is way easier to terminate.
I belive him. *My last garage improvement project wtih 52 year old fingers didn't like
working with 12 ga.

Somewhere I read that loop wiring is illegal. *Do you know where that reference is in the
NEC? *If I ever run another branch string, I'd be willing to run 14 out and back if it is
legal.

As far as I know there's no specific prohibition, but there are
several restrictions on parallel conductors that would make a loop
connection unacceptable.

See Articles 300.3 and 310.4.

--
Ned Simmons

What about an Edison circuit?
Are they still legal?

Two hots and one common. IIRC

Sure. If you have 120/208V Wye 3-Phase, you can go three hots and
one common if you want. All on different phases, of course.

The restriction is, you can not use a receptacle or other device to
splice through the neutral wire if it's a multi-phase circuit - you
have to pigtail the neutral with a permanent splice (wirenut) and take
the single pigtail wire out to the device.

Way too many receptacle screws go loose after many years, or worse
they use the Quickwire stab-ins that go high resistance... Then you
develop an unbalanced circuit, and the fireworks begin.

Tracked one of those down a few weeks ago - and if they did it in
three condo units (that I've found so far...) they probably wired the
majority of the ~1,000 units in the complex the same way.

To do it right, you need to ty-rap or otherwise tag that the neutral
is shared among those hots only, and be careful not to mix and match
hot to neutral relationships when you hit multiple-feed boxes like the
Kitchen Sink - where you have the three-wire circuit passing through
for Dishwasher and Disposal, and a Lighting and an Appliance
Receptacle circuit or two, all meeting in one two-gang box.

If you don't show discipline you can overload one neutral by
throwing the returns from a few more circuits onto it. Neutral wires
should not glow.

-- Bruce --