"Existential Angst" wrote in message
...
"David Nebenzahl" wrote in message
s.com...
On 10/26/2009 11:02 AM Existential Angst spake thus:

wrote in message
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On Mon, 26 Oct 2009 11:38:56 -0400, "Existential Angst"
wrote:

Of course, the wiring is old, cloth covered, but in BX, and
super-high quality. The wire seems to be nickel or silver
coated/tinned -- not just ends, but the whole wire. Curious as to
what the purpose of that coating is.

The wire appears to be only 14 ga, but still more than ample for 15 A,
AND each splice is wire nutted AND soldered!!

You answered your own question. They tinned the copper wire because
it usually was going to be soldered.

So you mean the whole spool/reel of wire was tinned before the
insulation was added, in anticipation of soldering?
To avoid the local application of flux?

One would still need to use flux (most likely rosin, as in rosin-core
solder), but the tinning would prevent corrosion to some extent, plus
make soldering easier.

At least that's my understanding ...

By the way, I'm glad you expressed your appreciation of this antiquated
wiring, which is often in much better condition than people give it
credit for.

Yeah, that wiring and the brass plumbing was a big part of the decision to
buy.
That and the incredible attic ladder -- I figgered anyone who took the
trouble to install *that* quality ladder in a g-d attic had to have done
the rest of the house right. I was mostly right.

I once expressed the opinion that some significant percentage of
electrical fires *must* be due to wire nuts, because cross-sectional area
of electron flow is greatly reduced, even on a properly twisted/nutted
joint, while solder virtually completely eleminates this conductive
bottleneck.

Ditto the spring-type clips on the backs of some outlets (which spell
disaster, imo, having seen a number of these melt out). Wire nuts present
the same problem, just not as egregious as these spring-contact outlets.

I was, however, sort of shouted down, but I still don't see wire nuts as
anywhere near as effective or safe as soldering.
The bottom line would be, I guess, to do IR drop samplings, under
increasing I, see what happens. Or measure temps at the wire nut joint
under high I, of various quality splices.

I believe it is NEC code that no wire-nutted joint -- and perhaps no joint
at all -- can exist without access to it in some kind of box/panel. It
was a NYC code.
--
EA




--
Found--the gene that causes belief in genetic determinism

I don't believe there has ever been any issue with the integrity of wire nut
splices. The real danger, and the reason that William Marr invented the wire
nut in 1914, was tripping around people's houses with a hot pot of lead,
while trying to dip the splices.
The particular type of cable you have will last and remain in good condition
provided it doesn't get overheated and dried out. Where you have it in
ceiling lighting outlets, where very high wattage lamps were installed close
to ceiling, is where it degrades especially badly.