I'm in one of those areas where we prune back K&T by wrapping it around the last knob and covering with several layers of tape until we have an insulation as thick as everywhere else on the wire. On the other hand, we have to keep the loom covering when entering a junction box - the idea is that the insulation of the old wires tends to crack when bent or where it comes into friction contact (as with wire clamps). I see tremendous variation - some areas it seems in great shape - others the insulation is cracked and paired with shoddy add ons. My biggest problem with K&T is the complexity - because it is spliced outside of boxes it is often hard to decode. I have to be very careful in removing it that I'm not cutting off power to half the house. And sometimes it bridges circuits and shares neutrals - a recipe for destroying expensive fixtures when you think everything is done and flip the breakers back on.
Thanks for sharing. Having a lot of experience seems imperative when working in the situations you mention. Good point about leaving the "loom covering" in place. The insulation seemed fine in my case so I didn't think it was very necessary.
Well alot of homes use K&T as well as Fuse Pannels ! Then you will find people splice Romex into it to give the elution they did a Rewiring Job ! Also people just replace the 2 prong outlets with 3 prong outlets to give the elution the wiring was up greaded !
@@tww1981 There's a belief out there behind the hear-say that by putting a grounded receptacle into a two-wire system, then it's "grounded". It's another example of people believing what somebody told them and the bigger the LIE grows, the more convincing it is.
@@frankpaya690 There is alot of "lets say -- creative wiring " to be found in homes ! That is something Mike Holmes found out on a episode of his show ! Although being a big name contractor on TV ; Mike Holmes should have known there is more than one way to feed both legs of a 240 volt circuit ! Hay it makes the job more interesting !
Hey Frank: The house I renovated was built in 1920. It had 110v single phase service. The 110 input was divided over two 60 amp cartridge fuses. Typically, one circuit was for lighting and the second was for outlets. The wires were coated with a shellac type substance. There was no heat insulation placed into the wall. When we bought the house the kitchen had a refrigerator, a chest freezer, a clothes washing machine, and a gas dryer plus a light. In the attic, again no insulation, the posts were mounted on top of the ceiling joists and wires were strung between the posts. A parallel set of wires about a foot to 18" apart was on circuit. The house was doubled in size with a replacement kitchen and a master bedroom. The service to the house stayed the same. As part of renovation we rewired the entire house to current code in 2009. We were going to leave the knob and wire arrangement in the attic as it was no longer connected to anything but the inspector wouldn't allow it.
Well done, Ben. I'm re-habbing my son's "new" 1929 house and we ran into Knob and tube wiring. Insurance companies care about this. We are re-wiring the whole house so that we can properly insulate and establish proper grounding of our system. You hit all of the highlights.
Ben, LEDs are all driven by DC and they all flicker! If they didn't flicker, the diode would actually burn out. The strobe effect you're seeing is caused by your cam capturing at a frame rate that is out of phase with the LEDs. Some flicker slower or faster than your cam, so some are just fine. I agree with everything you said about K&T. Only thing I'd have done differently is keep the wire in the loom tubing, and push that wire and loom through one of the box clamps for added protection. I've used a screwdriver to push open those integrated clamps in the box wide enough to jab the loom and wire in it. One clamp per conductor as you did. I also like to put a band of white heat shrink tubing around the conductor I've confirmed as neutral. Bummer about messing up those Knipex. Think of it at it as a battle scar in your journey to be a sparky. I have messed up at least three pairs of side cutters cutting cables "I could have sworn" were dead.
Higher frequency PWM would make everything less or not noticeable though. Difference of a few cents. Just old fashioned thinking. I agree with Ben. We need to upgrade the PWM frequencies on all dimmers! Godspeed!
Um no. They don't all use pwm type of power sources and even if they did, obviously some brands have mastered the art. Leds must be current regulated but do not require pwm or pulsed power sources. They are used in all kinds of equipment including indicator lights and are most definitely NOT pulsed in those applications. Especially when using linear power sources . Pwm allows better efficiency of power usage because you are not wasting it as heat which is what happens when using a resistor of sort to lower the current to the LED. Milwaukee has not mastered it's use and are terrible across the board when it comes to their lighting.
Funny thing about older homes is many craftsmen were stuck in their ways. My home was built in 1910 but the original woodwork screamed late 1800s. The flip side was the wiring was all BX, which was brand new at the time, along with a 30 amp service at 110 volts. There was no indoor plumbing or central heat when it was constructed. The BX cable I removed had tags on it from Montgomery Ward. (competing with Sears in the era) Odd to think the place had the "gold standard" for wiring but everything else was old school. Being an old mill town we had electricity and telephone long before many.... while still using a hand dug well and an outhouse. What a mix!
@@steveloux4709 ... true, but there was no user connection within the living area. It was strictly an engineering point within the installed system. Boxes grounded back to the mains panel was about it. I have never quite figured out if they even bothered to install a ground rod outside the home in that era... or if it was all bonded to neutral and returned to the transformer.
@@steveloux4709 But the further away from the source you got, the less effective the ground. Plus if the connectors weren't tightened properly, it becomes ineffective.
@@TheTurpin1234 sounds like you have done your own research? The ground of an AC cable is merely needed to provide an effective ground fault current path. I think casting doubt on its effectiveness due to the possibility of improper installation (loose/improperly installed fittings) could be applied to anything in electrical construction that might inhibit the establishment of an effective ground fault current path. Are there more reliable means to ensure an effective grounding program? I suppose that is why the Code recognizes certain installations require redundant ground fault paths, e.g. patient care areas. But if we confine ourselves to properly installed, code-compliant wiring methods, we can be confident in the safety of such installations.
@@rupe53 whether a grounding electrode exists or not, the benefit of the AC cable being bonded all the way to the main panel and to the neutral provides the most critical part of the grounding feature; that is the ability to fault large amounts of current to very quickly open the overcurrent device in a short circuit condition. The ground rod where present is primarily in place to dissipate the energy caused by a lightning strike and little more.
Thanks for sharing. I’m slowly replacing the knob & tube in my 1940 built home. When it comes to contemporary load demands, although the LEDs require a fraction of their predessors, they lighting is often shared with power or receptacles which are likely to be drawing more current than they’re designed to carry (such as a 30 amp water heater circuit being fed on maybe a 14 gauge wire). I have found several cases where the cloth insulation has warn through, exposing the conductor as it enters the box, so I suggest using the Supper33 you reference to wrap the insulation if you notice any deterioration and add a wrap of white on the neutral as well as a circuit number on the hot for future convenience. Where a splice occurs inside a box to mark the incoming hot so as to keep track of the direction of the current. The scariest thing I found was finding the Zinsco panel allowed some very hazardous circuits to hold, rather than trip the breaker- even after a hot and a neutral arched in a ceiling fixture, caused by the cloth insulation breaking down in a pendant light in the dining room. Fortunately, it was shortly after our first dinner guests returned home. PS- I would be very interested in a walkthrough of the old house you mention. Thanks again!
I will preface this by saying I wouldn't recommend this to anyone, but what I do when replacing fixtures on a ceiling that have had a history of being overlamped, I typically find the K&T wiring's insulation disintegrating in my hands. Usually the wire is #14 solid. I take a piece of scrap THHN wire and strip the insulation off a continuous length long enough to sleeve onto the existing wire where the insulation fell apart, then use a much smaller amount of 3M 33+ or 35 to tape where the old insulation meets the new insulation. Obviously if you get the opportunity, it would be better to re-feed the wiring with NM-B cable, but to make that legal, you really almost have to start over, rather than simply run the NM-B back to the next nearest K&T source, which technically is also a Code violation of greater issue.
Well of course your house at the most when it was built had a 60 amp service. My thoughts are if you have knob and tube abandon it yes it will be a chore but you will sleep better at night. Think about this I am certain you have seen old movies with those odd looking round light switches on the walls, well the wiring for those were most probably retrofitted in this buildings and the cuts to install them were plastered over. After a while you will get proficient at it.
I have ran into that old old wiring that replaced the knob and tube stuff and the cord wrap inside a box usually frays and if the wire is manipulated the least bit the black rubber just falls off the wires another thing you will find is copper coated steel wire from world war two. Found out about that when we did some junking in the early sixties and mixed a bunch of it in with good copper and burned the insulation off it to take to the scrap yard. Did not get squat for that load for sure.
We have so many Zinsco service calls, the bus bar always seems to burn out and breakers not tripping so they burn. I really do not like this knob and tube stuff. Eventually I'll change to commercial only.
One of the hard parts with finding the source to cut off old K&T is that several rooms (or half the house) may be on the one circuit. Usual electric service was 30 amp 110 volt meaning 2-4 15 amp circuits. Maybe one circuit to service all the bedroom ceiling/wall sconce lights upstairs; one circuit to service all the ceiling lights on the main floor and maybe one wall outlet in the living room for a lamp or two; one outlet in the kitchen for a mixer or iron and maybe a circuit in the basement for the lights. Typically when a house was built in the very early 1900's, the lights in all the rooms would be hanging down or have pull chains---no wall switches so everything would be live in the ceiling. A run from the fuse box might go north to south in the attic with drops or branches to the side spliced in to go to each bedroom light. You might have a hard time finding it to cut off without cutting the whole circuit (which isn't a bad idea). The mess you found is likely to be in other rooms as well.
I can tell you this much :: just because you have a newer home ,that does not mean it is wired right ! And watch out on buying any house ! Get a therough inspection done !
This... Is not accurate. Maybe a super cheap house wouldn't have switches, but here in the Midwest every K&T house ive seen has switches for the light fixtures in each room. Most of the time the neutral is switched for some reason, I know that was still legal until I believe about 1930.
I never trust anyone anymore when shutting off power. I also messed up a new wire cutter. I followed the wire from the switch to the bathroom fan box. I was aware there was power at the switch however I was not aware the switch was upside down. As a result I turned on the power rather than shutting it off. lol
Yeah, I started carrying a small padlock with me when doing work at friends houses to lock the breaker box. I was wiring my friends bedroom back in 2019 and the same breaker controlled the room I was wiring and the outlet in the bathroom on the other side of that wall. His wife(nice lady, but a bit of a ditz at times) thought something tripped the breaker when the outlet her hair dryer was in wouldn't work. She went downstairs and flipped the breaker back on, and I saw a flash... Luckily I was over their bed wiring the ceiling fan motor, because that put me straight on my ass.
@@Poptart133g I have a friend whose father, an electrician, was electrocuted that way. He was working on the wiring of a factory and had turned off the power and someone came along and turned the power back on while he was working on the circuits. NEVER RESTORE POWER UNLESS YOU ARE 100% SURE THAT NOBODY IS WORKING ON THE SYSTEM. ALWAYS CHECK -- YOU MAY SAVE SOMEONE'S LIFE.
First off, thanks so much - this video is very helpful. My 1916 built home has a mix of K&T, ungrounded BX from approx. the 1950's, and modern wiring. All the heavy hitters have been moved to the 100 amp service in the basement on newer wire. I had insulation blown into the house 20 years ago unknowingly and just learned this was a major risk, so am now doing a map and inventory of all my circuits to see what is the state of the state. Fortunately, the two remaining solely K&T circuits running from the sub panel in the attic (30 amps) have very few fixtures and only outlets and lights. But there are a number of circuits that are a mix of all three styles of wires. One with 17 fixtures on it - ugh. I'm currently moving as much off this circuit, with out having to open up the walls, all while trying not to curse the prior owners. My tone probe arrives tomorrow (yay!) and will be a big help. Also happy to have all LED bulbs at this stage. It's shocking (haha) that there hasn't been a fire. I will be doing as much as I can right now without opening walls, and will most likely leave some wire in the walls. Glad to know what can be done with the abandoned wire, and how to make it as safe as possible. For sure I will not be leaving any live segments.
If you can, I'd suggest moving all receptacles off the knob and tube. That way you don't need to worry about heavy loads. I'm on my second house rewire with knob and tube. I found similar mixing of newer wire spliced onto the knob and tube. In both cases the landlord said the house used to be knob and tube but was rewired. Not even close - they put newer wire where it was visible and left a lot of k&t. In the first house, I really think they had one circuit for all lights and outlets. Breaker labeling gets creative too. A breaker labeled Living Room was really the living room, the kitchen light and an outlet, an outlet in the laundry area, outside lights, and ungrounded outdoor outlet in a non-weather poof box (!), the light at the top of the stairs, the lights in the middle and back bedroom, the light and both outlets in the front bedroom. The house I'm working on now had the entire second floor plus lights on the first floor, and first floor bathroom lights and the flood light out back all on a breaker labeled First Floor. Lol. Watch out for lights fed from both floors. I thought I had everything off the first floor knob and tube, so I cut the wires that ran through the first floor ceiling. The light at the top of the stairs stopped working. The neutral was taken from the second floor, but the hot came from the first floor. I got that corrected, but there was a wall light in the back bedroom (the only light in that room) that fed up from the first floor knob and tube. One trick that helped me was to use my clamp on ammeter to see what was on the knob and tube going toward the kitchen. I turned on or plugged in various things and watched the ammeter. I could tell that the ceiling light, one kitchen outlet, the light at the back door, one laundry room outlet and light, and the outdoor outlet were all on that pair of knob and tube wires going from the dining room ceiling into the kitchen ceiling.
A tone probe ncvt is a useful tool, if you know it's limitations. I would highly recommend a tester or multimeter as well, if you're going to be doing anything with potentially energized wire (huge amount of information to be gained by metering things anyhow). Klein also makes a device that plugs into receptacles and lighting fixtures and tells you which circuit you're tapped into, at the breaker panel. It's like 30 bucks and may be useful for you.
Hey Benjamin. Great video. As for those LED lights, they are working as designed. To keep weight and cost down they use switching power supplies instead of transformers to drop the voltage, and then PWM to control the LEDs output with pulses of DC voltage instead of varying the voltage like on an older incandescent lamp. Usually not noticeable to naked eye, but will show up on your video at typical frame rate of 30 FPM.
K&T Wiring was designed to be "air cooled", so although the knobs "stand off " the wire an inch or so away from the combustable surface its run along. It also allows air to circulate around the wire. This is the reason some insurance companies now will not insure homes with K&T wiring. Most homes have had their insulation supplemented ( blown in,etc) in the attic and now that K&T wiring is surrounded by insulation. Frankly , the way the connections were completed back in the old days ( soldered!) The insulation is probably not going to be a problem IF the original installation ONLY exists. Problem is in 100 years there is any number of modification that typically happen in a house. And when it comes to electrical wiring there is a multitude of questionable practices out there. Many people think they can " do wiring". K&T wiring is extremely difficult to diagnose. You have possibly shared nuetral multiwire circuits, california 3 way switching or regular 3 way switching, switched nuetral circuits,etc, etc, etc...if you don't know what your looking at you can get into a lot of trouble. The " repair " part of K & T wiring is intentionally vague in the code because in many cases you really dont have a good viable way to repair it. I mean really , think about it, how many things do you own that you use on a daily basis that are 100 years old that have never had any maintanance on them? Well, if you have a house built in 1902 you may have (remnants) of wiring thats 121 year old and still being used. Its quite remarkable really when you think about it. I could go on and on, but I gotta go to work. Tim..
I played with MILES&MILES of knob&tube on Long Islands historic North Shore during my 30yr career. There is still plenty in service and in reasonable condition today. If the wires were never overheated. There is no teaching how to perform a repair. A volt ticker reads a broken neutral as if the wire is live. I hated going no power service calls at knob&tube homes. The last thing a customer wants to hear is, you have no choice but rewire the entire effected circuit in a finished 100yr old home. Consequently, I quickly learned what is restorable and what is not, through my efforts to restore power to 120yr old wires.
Thank you SO MUCH for this post. I have been searching for this information for almost a week. I have been back and forth from repairing or replacing the K&T in my 1900 home after I f**ked up and shorted the H&N. Even an electrician told me to cap it off and run a new line, but the entire 1st floor is on that one breaker. I had already run new 12/2 to the kitchen and bathroom, so I knew enough to be dangerous. The only issue I have is I am not sure where to fish all the runs to get them to the breaker box. The current breaker box is on the back porch and the K&T is coming from the basement. Do move the 100 amp breaker to the basement and/or run the wires from the attic through the space between rooms down to the basement and then back to the breaker box? Any help would be greatly appreciated 👏!
@@TheLowDownDog if the panel is on an outside house wall, run your cable into the basement and fish the cable up inside the wall behind the panel. If your plumbing vent pipe runs straight up from the basement. Drop a snake along the vent/drain pipe down to the basement and pull your circuit up. Leave a pull string along the pipe and you will not have to snake to the basement again. The gable end walls in your attic might be open to the basement. My house is 1920. Your house might be balloon construction, meaning there is no header plate to attach the floor of the 2nd floor, and block the path down the bay. The plate was called a ribbon back then. The last resort, if you cannot make an internal vertical pull, run the circuit up the outside of the building to the attic, sleeve your plastic case cable inside pvc conduit and install sil plates to protect the cable at entry points, top and bottom. If you use metallic conduit, bonding codes apply. I hope this helps you.
Had about the same situation with a pair of side cutters. Working in a basement on a 240v water heater, my coworker said ''yea the breakers off'',,,,, BANG!!!,,, ''HEEHEEHEE,,, IT'S OFF NOW!!'' 24 years later I still have those cutters with the arc mark!! Scotch Super 33+,,, the only electrical tape I used, until I found the Scotch Super 88+!
In the basement of a bar, I watched two people disconnecting the electrical wiring from the oil furnace. They had turned off the circuit breaker identified as "furnace". One of them dismantles the wiring, without any particular precaution, and without problems. Then while he has the cable in his hand he pushes it away. The cable touches the metal furnace. Fireworks!
Better to have left the original over sheath insulation on the wires and enter box through two different holes. Also best practice to disconnect unused/abandoned knob tube wire at source when possible.
Abandoned wiring shall be removed that is accessible NEC 725.25 and 800.25 and so much more I could share with you most of all understand the difference between being or not being qualified to perform any type kind of work and be able to do it safely.
11:26 House built in 1928. Upgraded the service to 200A and uncovered a true rats nest of K&T. Decided to gradually replace it all. I’m disconnecting it from the service and just leaving the wire in the walls. Running new romex and bringing sanity to the circuits. That long ago they just had lights and so balancing loads wasn’t really a thing. It is a royal mess. My advice: motion activation and wireless switches. Save your sanity!😊
Nec 2020 394 concealed knob and tube wiring. Also 310.14. I've been working on my wiring built in 1929. Upgrading to leviton lp420mp and their smart breakers.
Our 1880s house still has knob and tube in the walls and probably to the ceiling fixtures on the 1st floor. Where it is accessible, the rest has been replaced with modern-ish wiring. (Still some places without equipment ground.)
Speaking of those Knipex pliers that got damaged @9:00, I once had a buddy ask to borrow my leatherman and then he used it to jump the starter solenoid on a riding lawn mower using my knife blade. The resulting arc caused a small chunk of the knife blade to blow out.
wow. i have not seen knob and tube wiring in a long time. i know a lot of electricians, once de-energized, will jsut abadon the wiring in place - unless the walls or ceiling is down for some renovation
If I have to partially abandon a run, I take it back to the nearest knob, loop it, then coil it back on itself, then tape it. Use the rubber tape, followed by the friction tape, like they did originally. I know when I see a potential hack job when I see shiney vinyl tape. If doing a complete rewire, I remove all the wiring I can get to as well as the knobs and tubes. The holes left by the tubes are used to feed new NM cable. Another pet peeve are those that remove knobs by bashing them with a hammer. It sends porcelain shards flying. Use a flat prybar, push the knob to get the bar underneath and pry up. They come out quick and intact. No mess and faster than hammering.
Save the loom for entering junction boxes . Use White tape to identify the neutral . If possible use dual function AFCI/ GFCI Breakers for Lights and Two wire receptacle circuits . Older style boxes will not accommodate GFCI receptacles , with a Dual function breaker , a standard receptacle will work and satisfy the GFI requirement for two wire outlets .
@@Bludcharg4214 That is an option , but using a dual function breaker can save labor depending , for instance if old boxes set in tile , or all the boxes in the house are old style . Good way to protect a Two wire circuit with out unduly disturbing old K&T wire which should be handled as gingerly as possible if it is going be to be used .
My experience with Knob and Tube goes back over 70 years and what I recall is mostly bare wires because the insulation had just crumbled off. Of course my area was still running on 25 cycle 110.
Sometimes there was no insulation whatsoever. In the oldest iteration, one side of the house was neutral and one side was hot. They would just pull a single wire over to the light fixture. The leads would enter on opposite sides of the fixture so no contact ever outside of the switch or lamp base. Of course, back then they one light, one switch and one receptacle. In my own house, they had the receptacle on the wall below the switch --- ABOVE the live gas jet for the space heater. Mm mm mmm.
@@ricoludovici2825 I am 83 now so I can remember when the only receptacle was an add on to the single wire pair with a light bulb attached and a pull chain switch. Darwins law was in full effect.
@@poorfesor I saw a lot of bad KnT splicing with 1st generation electricians tape. You know the stuff: tar impregnated sticky cloth. I still don't understand why they called it electricians tape. It was fire-starter's tape.
Walk around Lowe's, Menards, etc in their lighting department while using the camera in your phone. Flickering or scrolling is somewhat common although It's actually not near as bad as it used to be. LED manufacturers have been getting pretty good at circuits smoothing out the flicker. Really surprised all the Milwaukee lights do...
It's something that I've definitely started watching out for. I feel like companies could stand to gain a lot by advertising lights that are "flicker free" although I'm not sure how many people actually care about that.
Super helpful! Just pulled a light fixture down. Surprised to find a knob and tube set up. We updated our electrical box when we moved in and well....anytime we pull something off the wall there's a new surprise. Do you have a video about connecting a new light fixture to this kind of wiring?
Hi Benjamin, I have been watching your RU-vid channel for over a year now and find you are among the best and easy to follow. I live in Thailand and doing some construction projects on the farm. I am from South Florida originally and have been in construction all my life. Here all electrical is 220v DC. I have one question, I have installed a separate 63a main breaker and a consumers unit that has a 63a breaker, as well. Is it a bit redundant to have the main breaker and the consumer unit both with 63a breakers? The reason I ask is I want to pull the 63a breaker from the consumers unit and replace it with two other breakers of 20a and 32a
I had an incident where my house remodel was denied insurance because the inspector documented it on the report, even though I told her it had been decommissioned from the breaker box and that I had not had a chance to remove it yet. It was stupid.
You do run across inspectors that have never actually worked in the tools and as a result don't understand how systems work in any structural sense so they're trying to memorize code rules, rather than going by a working comprehension personally of how something operates.
My home, built in 1959 has knob & tube (KT). When I renovate a room, I replace KT with Romex all the way back to the circuit box, if I can. But finished rooms and ceilings blocked that in some cases. In that case, I have installed a box to join KT with Romex leaving as little KT as possible.
Home built in 1959 with knob and tube??? are you sure the home was actually built in '59. That is very late for knob and tube. I've been in homes from the '30s that had the original cloth wire romex, all the knob and tube I'm aware of wad installed before WWII and never seen any installed after about the mid 40s at the latest.
@@markcrimmins1879 very cool. Seems they used K&T much later in certain areas of the country. In 1962 grounded romex had been around for a couple of years even before grounded receptacles were required, they would often wrap the ground wire , which was usually 16 gauge with 14 or 12 gauge hot and neutral during this period, around the clamp securing the cable to the box, you'd then have what is known as grounded two prong receptacles, this is where using the coverplate screw on the green tab of a 2 to 3 wire cheater plug will actually provide a ground, of course nobody used it like that.
Just bought a 1920 house with the lights still K&T. They seem perfectly safe and we will keep them that way for now. Almost all the outlets are romex wiring now with the exception of 2. Could we simply cap them off and keep them in a junction box where they are, even if power is running through them? That would be most ideal if its a good idea.
My house was built in 1887 (yes 1887). It was built with knob and tube wiring. I know this because I can some that is impossible to remove without tearing down walls which are all original. The wiring was hacked more way than I want to comment. There were splices from knob and tube to Romex back to knob and tube. Some in junction boxes connected to Romex and a few splices hidden in walls. I spent an entire summer Pulling 3,000 feet of Romex, installing a 200 AMP disconnect and 30 space panel board to get rid of all the knob and tube.
Those very early houses often had conduit exposed on the finished side of the wall and would go to a round switch with a twistable knob that you would turn clockwise to turn on and clockwise again to open.
I learned electricity using knob and tube at the Michealangelo school in Boston Ma. 1969 grade 9. went on to Charlestoen High School for grades 10, 11, 12. Maybe the best electrical school in Ma. at the time.
idk why but i like that idea and i like that light socket just because its ceramic and its repairable im familiar with the with k&t setup because my grandma and grandpas shed/house garage has that wiring setup never had a problem with that they said its original
My house still has capped off gas lines in the walls, and knob and tube. I don’t think gas is still in the pipes, but I’m not certain of that. I need to check that out for sure.
I think you should have kept the loom sheathing on the wires as it was intended to provide extra insulation when the wires came close together as when entering a fixture, and the wires had to come in through different holes. Otherwise the wires were to be kept a foot apart during their run from box to box. Splices could be done anywhere, not needed to be inside a box.
I replace post and wire. The inspector made me remove the disconnected post and wire. Post and wire used bare wires on porcelain posts so insulation or any contact with other surfaces was not allowed.
We have a lake house in NH built by my great grandfather and wired with knob and tube. In the 1950's, my father figured it was dangerous and also wanted to add more wiring (the old insulatiopn was dried up and cracking). So, we tore out all the old wire and installed new romex with all new fixtures.
I've always removed the knob and tube that I've encountered. If you don't someone will likely try to use in the future. If you knock out the insulators the hole is ideal for 12/2 or 14/3 cable, so no drilling.
Just bought a house built in the 1920s. No insulation and prior to doing insulation we need to have active knob and tube wiring removed. I'm a fish out of water on this and it could be expensive!
Now I need to go see if any of this is still in operation or at least present. This house was remodelled in the late 1990s so I doubt there's any, but now I'm curious. First time I've ever heard of this though.
I would not have put both of those wires through the same hole in the junction box. Although the insulation on knob and tube is generally pretty tough stuff and has stood the test of time I have seen it crumble and turn to dust and more than a few occasions depending upon the location. For that reason, I would personally feel much more comfortable having those wires separated going into the box.
I have knob and tube and I have two switch and they are powered by two wires and then to the hall light and then to the yard light how to wire to have it done so I can control each one by it's own switch
If I have partial knob and tube wiring in my home, and the rest is up to date wiring, all being fed by the main breaker. Kind of hard to tell what is feeding what.
35 year electrician. I'd never add a box if my goal is to abandon the K&T. Take it back as far as you can, cut a 6-8 inch tail, wrap it back around the last knob, and wrap it around itself. Tape well and call it a day. That's how the original system was terminated.
If in great shape, still needs a ground but can continue to use and heavy enough. A lot of old houses only had the one light in center of the room and some were powdered by 36volt generator and glass lead batterys. Other appliance would plug in to the light with an adater. I use to pull out all the old if not able to use. Then on day was asked why. Waste of time. I still make it totally disappear any where around the new service panel as to eliminate temptation.
My 1910 house is a conglomeration of knob and tube, cloth braided insulation two wire romex, and three wire romex. With most things connected to the knob and tube. 😬
I worked on a house with knob and tube. In one instance the entire wire lath wall was electrified by failed tape termination. The box was filled with newspaper and plastered over. Discovered when i scanned before Hanging a painting. Wasted power for years. The next instance almost killed me. I was fixing lowered ceiling tiles and was shocked. Two burns on my arms.. Romex was patched into knob an tube and it rubbed on the furnace. Electrifying the whole grid . Now i test everything before doing my Non-electric work. If it is metal it can be energized.
Great Video! Regarding work lights... To Dim a AC to DC LED work light usually uses PWM. The higher the frequency the higher the price. Better options are definitely available, but more expensive. I agree with you however. Not sure why $1 more of parts and labor would result in a price increase that is beyond what most people would pay (Just because their lights are video compatible). Anyways, don't worry good dimmers are going to go more in fashion soon. Partially thanks to people like you who complain about dumb cheap lighting driver decisions. Spend a dollar more. Charge us two dollars more. Companies need to start making high quality again, without 1000% markup. Why make garbage? Granted, most people don't care about whether their work lights are for video, other repercussions of LED dimmer shortcuts are buzzing, EM interference in sound-systems, and bad dimming profile. Anyways, thanks! Your videos are helping me a lot. First time new construction plumber and electrician! I'm used to smaller systems!
It seems like those Milwaukee lights use a PWM controller for dimming rather than using resistive dimming. When you had the one on its brightest setting, I didn't see flickering. They may have went with that method for battery life longevity. I'm thinking that using rapid switching with a constant voltage may be more energy efficient than using resistive dimming which just pumps out more and more wasted energy as heat the dimmer you make the lights. Using PWM may allow the light to run substantially longer on it's dimmest setting. If you want to use those lights still, you may be able to find the brightness you like best and then adjust the recording framerate and shutter speeds to best match the frequency of the light if your recording equipment allows it. Someone also mentioned that LED's flicker in order to not burn out. That is not correct, but a flickering LED would stay cooler while looking less bright. LED's can run on constant current without issue as long as a sufficient heat sink is used when needed. In essence, they work from electrons leap-frogging across atom valences that makeup its semiconductor material to fill "electron holes". Most LED's have a normal P/N junction temperature of around 30 to 60°C with ambient room temperature (20°C). I believe LED's can reach about 70°C before degradation starts. If a heat sink is used, you can keep them from reaching that temperature to a point and run them brighter.
My house was built in 1916 with K&T wiring. Most of it has been replaced. I tried changing insurance companies a few years ago to California Casualty and they would not insure my house. Their policy is if it has any K&T they will not insure a house no matter how well the conversion was done.
What is amazing is how long electricity had been around when K&T wiring was implemented and they still had no idea what a ground was. I wonder what the life expectancy of an electrician was back then?
Speaking of Milwaukee tools I bought a Milwaukee door knob drill kit for installing door knobs and dead bolts and it was junk also, the Ryobi kit worked much better. It's too bad they've gone down in quality and they have to know it.
The biggest thing with knob And tube is, it’s perfectly safe as long as you don’t insulate around it. I’ve Been going to a lot of houses to rewire attics so they can insulate.
Where I am, when I encounter knob and tube wiring, it's mandatory to disconnect it and run new cable for the circuit. Makes it difficult when you're in an old house with a fused distribution box. (Which is also required to be changed out..!)
We have knob and tub wiring in our bathroom. We have no outlets in the bathroom just s switch and you can see how the knob and tub is run from the switch to the light. I just hope its not like that through out the whole house. I know that the cost of rewiring is between 8k to like 30k at least here in California.
There's better heat dissipation, being as the conductors are not encased in any sort of raceway- (Conduit), The drawback is since they're not in a raceway, rodents and the elements could deteriorate the insulation on the wires. In that era, there weren't as many dedicated circuits or fault grounds, that's what makes those old systems not as safety- sound as today.
The question was "Why do button and tube wiring need better heat dissipation?". Electrical wiring heats up, even modern wiring. By the way, there are still some rules to follow for the heat dissipation of modern wiring. For the button and tube wiring, I believe the rubber insulation was more fragile to heat.
@@sg39g correct. Because knob and tube systems almost always date from before WWII , they are at least 75 to 80 years old at the newest, there's no tell what the temperature rating of the insulation was. Modern NM aka romex, is rated 90°C but we size the circuit protection using the 60°C column, so modern wiring has a pretty good margin of safety. Older pre 1980s NM was typically rated 60°C. Overhead light fixtures would make the insulation on the conductors very brittle and are known to crumble off with the slightest movements, especially when homeowners using 75 or 100 watt incandescent bulbs in fixtures designed for 60. The new NM solved that.
I know this is at least a year old but incase no one has given a solution to the LED's. All LED's flicker, its just doing it so fast that our eyes don't pick it up. Cameras aren't like our eyes and what you are seeing isn't flickering per say but a rolling shutter effect. It kind of like what you'd see when videoing a spinning wheel or propeller. Most cinema/video lights aren't LED for that reason and the ones that are are usually of a very high frequency. The frequency of the light isn't agreeing with your camera so the simplest way would be to adjust the shutter speed and/or framerate that you're shooting at. I had this issue with some LED bulbs I used to use and was able to find the sweet spot with my camera.
Now you know why those lights were on sale... Sad to actually see the Milwaukee name on a turkey. So it flickers like that to the naked eye? Or just to the camera? I was pretty lucky with my house because all of the remaining K&T circuits began at a junction box, with Romex leading from the main. So I replaced all of that K&T with Romex. I ain't goin' in no main box! My house is from 1910, and I think electric lights and receptacles were added around 1920. All of my near 100 year old K&T insulation was still in good shape, except around some light fixtures, where heat had degraded it. Imagine doing all of that 100 years ago, with hand-drills, and replastering holes...
Hi Benjamin ! I have some knobs and tubes like 3 circuits I just gonna disconnect them in the main panel and run new romex what do you think about this approach?
I got the same issue , I can tell you it’s different in every location Here where I am it is allowed by code but insurance will be hard, there are some that are fine with it some are not . So like buddy said remove it when possible and call your insurance provider and ask what there policy is
@@waytospergtherebro increasing the frequency would actually resolve the issue. But there might be reasons this can't be done. In any case there won't be a firmware update.
Dimming of LED lighting can only be done with Pulse width modulation which is effectively adjusting the duty cycle of the light. Just by non dimmable led lights if you don’t like the flicker.
And the customer doesn't even stop and think about the conflict of interest, of having the person who's going to do the work- tell you you need to replace what's existing.
I have encountered a few knob and tube systems but the insulation was always bad and needed to be replaced. The wire gauge was also smaller than I like.
I've noticed the opposite, it's number 12- throughout the house, rather than number 14, Even though originally it wasn't any greater than a 15 amp- overcurrent, as well as some silver- clad copper conductors.
Since you are killing the K&T line, why didn't simply twist the two wires together and wire nut them so nobody else can think of reusing this line. Besides, electrical tape is useless with wire nuts.
