Can i leagally install a Knob & Tubing installation?

You can extend an existing system, but it could create problems with the grounding requirements for switches & receptacles. You can also install it if your AHJ gives you special permission.

K&T is still in the code book, see article 324.

I don't have a clue where you could buy the knobs & tubes. As Red Green would say, you'll probably have to borrow a few from someomes old house, preferably when there is no one home.

Tom

hmmmm, well i have a K&T feeder ( a tad heavier wire) up to an attic. There it enters an exposed fuse arrangement.

The branches from there out need attention. This particular job has "for-now" aspects and "later-on" ones.

I only know how to rip this stuff out, not replace it, don't even know what type of wire it is...

sparky,
For heaven's sake! Why would you want to???

Gj;
i really don't, but these are the Q's customers ask. They don't know K&T can turn holy water to steam 8' away like we do!

These Q's do bring to mind, however, the NEC's K&T 'nostalgia article' . I would assume it to be more trouble $$$ wise than it's worth ( my cop out answer to the customer), besides, i really don't know how to run a 'compliant' K&T circuit! Do you?

I've seen methods of installation in older American Electrician's Handbook copies.

My guess is lots of knot tying!

If asked I would simply tell them that standard practice is to replace K&T with NM cable. And NO....I wouldn't know where to start with a K&T installation.

To me, it would be kind of interesting to do some K&T installation, just to see how it "felt" to use that method.
Couldn't see putting it in some structure for permanent wiring, but it would make a cool display, or maybe a company based tech lessons thingee done in the shop.

Install a few circuits, some switch legs, then heat it up.

Would be cool to say to myself "I have installed Knobs and Tubes, plus separate free air conductors, and in the K&T fashion".

Just my thoughts.

P.S. what's the Insulation type for K&T conductors?? i.e. what's the materials and the NEC / ANSI / IEEE / ?? recognized abbreviations [like THWN: T=Thermoplastic, H= Heat res. {75c}, W=Wet location, N=Nylon jacket]. Think these are correct [??] Feel free to blast away with the flame thrower if needed

Scott SET

Scott;
it would be kinda cool, huh?

I can't find much on this, materials wise.

Methods wise, i have only met one retiree how was around to install the stuff.

So we'd have to dress in era clothing and apply tools as was done!
-bit& brace
-knot tying manual
-coal fired soldering irons

I saw somethng like this once. Don't know if its O.K., but it looked good-

Entering into NM boxes through separate entries, each k&t conductor was supported with a knob within a few inches and protected with loom (the outer cloth covering found on k&t)at entry points. From there NM cable was spliced in to feed non-grounding receptacles in NM boxes. I would guess the best thing to do would be cut the ground wire short enough to make it unusable. It looked neat and sound, but I don't know if it is acceptable.

(Off topic question: Does anyone have a chart of insulation types?)


THWN would probably be better than whatever was used 50-60 years ago for K&T. But is that sufficient for areas with sunlight exposure?

Dspark;
oh no! not the [sunlight] code again!


that can be one pain in the A** of a code to meet!

dracula must have served on that CMP!