I have a number of places in my victorian where I want to upgrade from knob and tube to romex, but can’t get all the way to the final device.
My local electrical inspector says the only way to terminate the knob and tube is with a pigtail device that looks like a wire clamp with round phenolic bulb through which the hot and neutral wires pass.
Anyone know of a source for these pigtail/clamps? Or a reference in the electrical code with which I can suggest to the inspector that a junction box and tube insulation is okay?
Replies
I usually keep one or two of these fitting on the truck. Unfortunately seeing as that I have never seen these on sale at any supply house getting them from me would involve prying them from my cold, dead hands. To date I have been lucky to have just enough. Sorry.
Try a local electrical contractors who do lots of old work. When they rip out K&T they usually get a few of them. That where I get mine. Also try electrical supply houses. Some houses have extensive catalogs that can be ordered from. Don't be put of by employees who have no knowledge of the fitting or the contents of their catalog.
The most sound action would be to replace, or bypass, the K&T all the way to the boxes and eliminate the problem. Old work contractors have special techniques for getting the new wire there. Sometimes involving strings, tape, fish tapes, vacuums and not infrequently whips, chains, various precious bodily fluids and harsh language. Consider getting one to look at the situation. You might be able to act as a helper and learn something or at least get advice on methodology.
I will ask around to see if I can find some of these fitting for you.
I'm still looking for the fittings.
Along the way a friend reminded me that in one case we didn't have the correct fitting. After carefully reading the requirements and consulting with the inspector we ended up bringing the romex into a Bakelite switch box, a thermoset plastic as opposed to PVC or metal, and without cutting the wires running the neutral and hot through the two holes at the opposite end of the box. Picture a large "Y" made with romex stripped half way and the box situated in the center of the "Y". The box was nailed into place normally and a Bakelite blank cover, the stiff plastic ones not nylon or metal, was installed.
The inspector concluded that it was functionally equivalent if not superior to the regular fitting. Realizing that the K&T was far more hazardous, it was in especially bad condition, than our irregular "fitting" and knowing that this was a singular situation he went along. Your mileage may vary with the local authority.
Your best bet, IMHO, would be to replace all the K&T and avoid the problem altogether. If you can't do that ask the inspector if he would allow the solution I proposed. If not keep trying to locate the fitting from a local source.