On Thu, 10 Sep 2009 19:47:25 -0700, David Nebenzahl
wrote:

On 9/10/2009 7:34 PM spake thus:

On Thu, 10 Sep 2009 16:43:09 -0700, David Nebenzahl
wrote:

But there's one thing about the old wiring that's puzzling to me.
Usually K&T runs are done with pairs of wires (Hot & neutral)
running alongside each other, and in most cases that's followed
he a run up into a wall will have a pair of wires going up into
the subfloor.

But there are a couple of places where a *single wire* is routed up
out of the basement into the house above. In these cases, the wires
are all hots. No corresponding single neutral wire anywhere nearby.
Presumably the neutral side of the circuit is tied to the neutral
of another pair of wires.

This, of course, makes it difficult to map these circuits, since I
can only assume that the neutral connection is made to the neutral
wire corresponding to the hot wire. That's my operating assumption,
anyhow: my plan is to simply replace these single-wire runs with
Romex, using only the black wire. (Hmm, wonder if they make 12-1
Romex w/o ground? Probably not.)

Anyone ever seen this situation in an older house?

Typical "ring wiring" In the low current requirements of years gone by
it was not uncommon. The first house my folks bought in 1958 only had
2 circuits. All K&T, and the "live" was connected to the fuse at both
ends.

Apparently this house has a couple of partial "ring" circuits in
addition to more conventional (by U.S. standards) wiring.

What you soon learn working on old K&T houses is there is no such
thing as "conventional"