Photos Courtesy of Electricmanscott:









Here is some knob and tube wiring. All wiring is still in use.

-Electricmanscott

[This message has been edited by Webmaster (edited 03-21-2003).]

A common sight here in the Northeast.

I would guess, from my experience, that the majority of older homes in New England (and other places as well, I'm sure) still have the original K&T in operation.

How common is the fused grounded conductor shown in the first picture?

Very common in old knob and tube installations. Why? I don't know. A little before my time!

Electricmanscott:

Thanks for the photos!

What are the connectors on the end of the armored cable called? Are they being used properly as pictured? Maybe it's the angle, but they don't look like the ones that I have seen (I've seen the ones used to bring armored cable into a metal box)...looks like there is a rubber boot or washer present to cover the metal??

What exactly is that lampholder in Picture #2???

It looks like some home-made kluge made out of a pony-cleat socket and one of those brass lampholders with the paper insert that are used for table lamps!! I've seen (and even have some at home) pony cleat sockets and surface mount lampholders with pull-chain switches...but nothing quite like that.

Any way to get a closeup? I'm curious.

As far as fused neutrals, I've read that that practice harkens back to the days of DC, where fusing both sides of a circuit was a good thing.

Naturally things stayed like that during the switch to AC...


[This message has been edited by SvenNYC (edited 03-23-2003).]

Those connectors are used as shown. They are to transition from bx to knob and tube. I will send in a closeup of the lampholder.



(Image inserted)

[This message has been edited by Webmaster (edited 03-23-2003).]

Fortunately,the only K&T that I have ever ran across was in old rundown farm houses no longer habitable !The old houses were in disrepair and usually being used to store hay bales.

[This message has been edited by txsparky (edited 03-23-2003).]

OK....now...to my inexperienced eye....that lampholder (extreme closeup picture) does look like a kludge.

Can anyone tell me otherwise?

All the pony-cleat receptacles (both bakelite and ceramic) I've run across, the screwshell is integral to the insulating husk - even the ones with a pull-chain switch.

Never seen some half-and-half thing like that...it does seem pointless. Creative...but pointless.

Also, am I alone in thinking that transformers for bells should be in a protective enclosure? I've never been comfortable with those things just nailed directly on a beam like that (first picture).

ThinkGood, those are transition fittings. They also were made to fit on EMT and rigid pipe. They are similiar to a weatherhead, with an insulated dome that the wires poke through.

Thanks for the explanation!

Sorry about bringing up an old thread, but should the butt splices in the 3rd picture down be enclosed in a box? It doesn't look like it was possible to do that here, though.

That fitting, from threaded female to insulated part with holes for wires, is called an "A Head". Creighton.

Sorry, I have to properly answer Thinkgoods question. It may be called a head but thats the first time I heard of that. I am an electrician from the Boston area so I see these quite frequently. They are called "ROSETTES" because they resemble roses before they bud. Now their could be a very tiny possisbility that i am wrong or maybe its a regional thing but seeing that my father is also an elctrician and also has has had the experience of hooking them up personally useing the old Western Union Splice hitch with solder,,, which by the way, taught me how to do one,,who am I to argue.

In the top photo,
What do them transformers feed?.

The transformers feed doorbells.

Steven, south of Boston we never called those "Rosettes". They were always called "A" connectors. I have installed some myself on knob & tube repairs. The last supply house that carried them around here has long since gone out of business.
Al

Never saw such a bell transformer around here. Even the oldest one are in a nice black bakelite enclosure with shrouded terminals. Modern ones are designed to fit a DIN-rail panel.

I think if something like the old stuff on the wood were mounted like that there would be a sheet of asbestos between the wood and the electrical stuff.
We had some light switches that were screwed to the wooden door casings and they had a hand-made asbestos backing. Carefully removed it...

Sven, to answer your question about the lampholder....
It was commercially manufactured, is being used as intended, and pre-dates the current type of "keyless."
It is also missing a ceramic tube, or funnel-shaped, piece that slipped over the bulb socket. The darn thing probably came loose during a bulb change, fell to the floor, and broke.

OH MY GOD, RENO; I had forgotten all about this thread!!!

Thank you very much for your answer regarding the lampholder I was posting about.

A little off topic, Harvey Hubbell received the patent for the pull chain type switched lampholder Aug 11, 1896.

Not to be bothersome, but is that a broken knob in Pic #2?

Hi there Hemingray,
Welcome to ECN!.
Looks only half broken to me.

[This message has been edited by Trumpy (edited 04-21-2005).]

lol, you're right. it IS half broken, the top half that is.

[This message has been edited by Hemingray (edited 04-21-2005).]

Could someone explain american 'knot and tube' wiring to me? I see a lot of references to this in posts.
Alan

"Knob & Tube" is the wiring method used (for the most part) in these photos. One of the older wiring methods, it was widely used from about 1919 until the late '50's.
In this method, the "hot" and "neutral" wires are strung separately along different framing members (appx a foot apart). Only at the device box do the two wires ever get close to each other.
When run parallel to the stud or joist, spliced, or changing direction, the wires are held in place by porcelain "knobs". When passing through, the wires are passed through porcelain "tubes." Likewise, when entering boxes, the wires are further protected by woven cloth tubes, called "looms."

And if you watch old Tom & Jerry cartoons, you'll often see a depiction of K&T wiring on those scenes of Jerry's pad inside the walls......

Paul, I haven't watched cartoons since I was knee-high to a grasshopper.....you've given me a reason to start again!

We in Maine always called those transitions from BX to K&T "Endo's"

K&T wiring also is a fairly good rat exterminator -- but does get the lights to dimming on their own a bit

in that last picture, is that a HOT wire spliced into a NEUTRAL wire? (black > white)

maybe it's a switchleg

In earliest times, grounded conductors were always fused wherever ungrounded conductors were fused. By 1922 (the oldest NEC in my possession), it was realized that this could cause major headaches in multiwire circuits, thus this practice was no longer required nor permitted. However, authorities were divided for many years thereafter over whether it was safer to fuse or not to fuse the grounded conductor of a two-wire circuit.

I have catalogs from the '30s that offer equipment in a choice of fused or solid neutral, depending on what your local inspector wanted. One 1936 catalog offers a "GROUNDED CIRCUIT PLUG-- Designed for permanently grounding neutral". It was to screw into an Edison-base fuseholder. (The professional alternative to pennies!)

The company where I apprenticed had two old porcelain 3-pole 30A fuse blocks on display in the shop. Each had a piece of 1/2" all-thread soldered into the neutral fuseholder.

I think in some areas, neutrals were fused into the '40s. I've never seen this in work from the '50s.

[This message has been edited by yaktx (edited 02-03-2006).]

Double-pole fusing was also used in Britain well into the 1930s, although I'm not certain the exact date that our IEE decided that it wasn't a good idea after all and specified that neutrals must not be fused.

Paul, I seem to think it was the 1937 Supply Regs that changed the UK to single pole fusing - I need to check to be certain, but it was certainly around that time.

Around my parts, those little ends are affectionately known as "monkey-faces".