My grandfather worked for Penelec in PA, all his life and retired in`1965. When I was a kid, probably in 1967,68, I remember him telling me that after a heavy thunderstorm, back in the 1940s, someone called and said they were out of power. His crew went to the house and found power was available at the entrance. They went inside and there was no power. They started testing and found none of the knob and tube lines had power, he grabbed one of the wires and it fell apart, there was no copper in the insulation. They checked the whole house and most of the copper in the wires was vaporized by a lightning hit during the storm. The people needed to get their house totally rewired.
As a lineman for 25 years in a modern world I'm thankful for people like your grandfather who paved the way for us. I can just imagine him being called out. I also think about the first lineman who knew nothing and every death was a learning experience. Even though I didn't know him I can call him a brother.
I think the house needed rewiring before the lightening. The lightening would have destroyed any type of wiring so just a good push & justification for upgrade
I actually learned how to install knob and tube wiring when I was in vocational school in the 1960’s. I think it was just a way to introduce us to something we’d find out in the world, as well as to visualize circuits. Very cool.
My grandfather's two story house had this wiring. The first floor had wires to one leg the ceiling for the other leg. The ceiling of the second floor was the same leg in the floor of the first floor. The basement my grandfather wired
"They made things to last." What a concept, produce and use quality material and items and here a hundred years later they are still working just fine.
There is actually a big problem with the knob and tube insulation. The insulation, when repeatedly heated, becomes extremely brittle with time. You almost always see this around light fixtures. It is probably the reason why knob and tube is considered such a fire hazard. I’m guessing the insulation is also not very fire resistant.
@@TechHowden no the main thing that makes it dangerous is the coatings become decrepit and fall off leaving bare wires. I've seen it hundreds of times. I remodel houses for a living.
“They made things to last” is a bit of a paradox. They also made things poorly back then, but those items didn’t last so we don’t see them anymore. Hence why people tend to associate old items in general with quality, even if it’s just a few select items that were built well.
In "my days" in HVAC/R service, "the boys" were installing a retrofit system in a very old farmhouse. I was up there installing the AC tubing/ controls and part of it was back in a closet against the roof pitch. One of the guys says "what's this wire here for?" BARE WIRE. One look and I grabbed my meter. YUP!!! Still live, still being used. BARE knob and tube This was about 1985-90-ish
Found one of those little surprises doing renovation work on my 1922 house. Wiring had been upgraded to modern standards, new breaker box, but an end of run on one circuit had the old knob and tube (same situation, tiny spot that was hard to get to). No bare wires, but the insulation had degraded so badly that it might as well have been bare. Luckily, even as a rookie DIY guy, I had the presence of mind to check with the meter. To say this got my immediate attention would be an understatement. About 1997. Kind of scary to think how many of these time bombs have been left by past electrical contractors or homeowners just waiting to start a fire or electrocute the unwary. Note, the only reason I discovered this was because I was taking out some of the old lath and plaster walls - had the plans been different that hazard could well be hiding in that house to this day.
@@Intelwinsbigly Well I think that's a bit harsh, since not everyone (talking homeowners here) might not recognize it for what it is, and may encounter it when not intending to do electrical work at all. I'm willing to forgive ignorance to a point, but never out and out risky stupidity. I learned my lesson at 5 years of age by sticking a metal object into an outlet, so I have a healthy respect for what electricity can do and always test and retest anything I encounter, lockout, retest, then get to work. And I've learned never to trust someone else's work but to verify for myself.
I remember my great grandmother’s house had this type of wiring around 1960. The house was built around 1890 something. There was a hand water pump at the kitchen sink, and a cistern outside to catch rainwater from the roof. The cistern was divided through the middle by a wall of brick, two bricks thick. The water came into one side, and the brick wall acted as a filter. The water was drawn out from the opposite side from where it entered. The house had lathe and plaster walls. When she passed away, the relative who inherited the house had it gutted and brought it up to code.
I was born in 1986 and the house we lived in had this knob and tube wiring. My father sold the house around 1996 as I recall. Also had lath and plaster walls.
Superb and simple explanation of early wiring technology - have seen it many times. My dear old dad was an electrician - finished his apprenticeship at Standard Telephones in England in 1919. After a spell in the British Army in India (1921-1933) in 1933 was employed by the Mount Royal hotel in London until his retirement in 1980 - having worked as ‘sparkie’ for 47 years. Electricity in all its forms is maybe the greatest modern invention.
I grew up in a Philadelphia rowhouse, the third floor was never rewired, it still had the original tube and knob, their was a junction under the floorboard in the hallway on the third floor,it looked as good as the day it was installed. However, my house was built in 1900, and wired in 1911 for electricity, according to the city records that I found in city hall. The city back then required that any modifications made to a pre existing property needed to be doccumented.
My parents bought a tenement flat in Glasgow in 1961 and there was still gas lighting in the hall and sitting room. The gas lines were still in the walls of the other rooms, the previous owners had removed the light units and just closed off the gas supply to the rooms.
Knob depth of 1" was good at keeping blind screws at bay too. Pound a nail in a wall to hang a picture. Boom. It was also nice to see the layout work, with both the hot and neutral running in the same void (plenums) between studs and trusses, but at the same time opposite each other on different studs. Professional electricians at the time, always kept the hot on one side, (I believe it was north or west), consistently throughout the house for reference
My old bungalow had hot wires in the ceilings and neutrals in the floors. Electrical receptacles had a wire of single conductor going down and a single conductor going up. Lights were similar, a wire from the ceiling to a bulb, then to a switch, then through the floor. Nothing ever backtracked... and that was 1940s.
as an electrician from 1967 to 1995 i've done a lot of work on knob & tube wiring. if it is left alone & not "messed with " it is perfectly safe, however, this is rarely the case. i spent a lot of time re-wiring buildings to remove knob & tube for nervous insurance agents & homeowners. my house was built in 1906 with knob & tube. i sleep just fine. from 1995 to 2017 i was a electrical safety inspector for a major ohio city. better inspecting than working on. most of the time needlessly. if knob & tube is inherently flawed, most of the houses in oakwood, ohio would have burned to the ground years ago.
I'm an electrician in Dayton, OH, started back in 2003, residential new construction and service. I hated working in Oakwood (damn Jenkins) with their city reality presale inspections and the large amounts of K&T that's still there. Have twice run into that hideous "Carter" or "California" Threeway as well down there. I concur on the "leave it alone". Once you start touching it, it crumbles away. Did you know any of the Mont. County inspectors? Bobby Spencer that passed, Gale, Neal? I've lost touch with who is out there now, after going to be a nameless Mook for commercial companies.
@@Salty_Balls if k & t insulation crumbles when touched, it should be replaced, probably from being overfused in the past. jenkins does not wok for oakwood, just does electrical inspections. oakwood does their own pre-sale inspections. knew all the inspectors you mentioned.
@@garybrown7044 If it was inside a box, we just heat shrinked it with tubing and then taped it (was usually just a service call situation). Outside a box, wouldn't touch it period unless it was to remove. I just hate Jenkins, as a general comment, add Neal to that, and the whole city of Oakwood. Never been a worse bunch of homeowners then that town. That city needs an enema. Ever bump into a guy named Jerry Deischer? One eye, big old drinker nose, tough as nails, a little scary? He's been dead awhile now, 8 years or so, but he was around a long time, not as long as Sheriff though.
I save knob and tube joints and look at the connections when i eliminate it.most folks dont realize(the joints are soldered). I agree if knob and tube isnt messed with or overloaded,it's fine for the most part.
@@benbradshawjr2856 my grandfather installed knob & tube before ww-1 & after until approx.1932. i still have his soldering "copper" & gasoline fired blowtorch. he drilled holes by hand. he bought solder in 5 lb. spools.
Even today, where K&T is frowned on and frequently removed when encountered, it generally works well as long as you NEVER TOUCH IT. As a service guy, I hated opening a box up and moving the old wiring around. As long as it just sits there and isn't moved it's really not an issue usually. But when you move K&T around, you find that as it moves the rubber insulation crumbles away and the woven sheath falls apart, leaving the conductor bare. Had to many a times apply heat shrink tubing back over the conductors to give it some form of insulation again. Best to leave it be if at all possible.
It’s mostly frowned upon by the Insurance Industry, due to losses. And it’s frowned upon by the BuildingOwner when they are told by the Insurance company to upgrade or no Insurance. Lol.
The house I grew up in had the remnants on knob and tube but had been “upgraded” to the two wire, tar and cloth cornered cable.... like Romex, but worse.
Tube and knob was a well engineered concept of wiring, the wiring itself stood the test of time, it was Nickel wire covered in rubber then cloth wrapped, and then placed in a loose casing of burlap tubing, I have seen where rodents ate this insulation, this caused numerous fires back in the day im sure. Great piece! I will subscribe.
Back in the 60's my grandfather dynamited stumps to clear a part of a field. In the 70's ( after he died ) they found his stash. 3 sticks and blasting caps wedged between the sealing and the wiring of an old shed. Yes it was safely removed. As a side note.....Yes it was fun watching the stumps go up into the air. Down side was cleaning up the mess.
Working on a bathroom renovation in Hewlett- New York about two years ago, 2019, saw knob and tube wiring running to the attic. Was told not to worry it was all in disuse for years. Put my tick to it, yep,still live running the attic light. My daughters house in Patchogue New York, around , five years ago, 2016, when the sheet rock was removed on the second floor, found the knob and tube tied into the Romex wiring behind the walls
I remember the nobs and tubes but the wires in our old house had almost no insulation left on them. Dad replaced them as he could but they were there long enough for we kids had plenty of time to find them in the attic as we explored our first home.
My family had a house that was built in 1903 at least that's the only records we could find of it. It had knob and tube wiring that still worked in the 1970's. The house also had a barn in the back yard with spots for 2 carriages and two horses with quarters for a stable boy above it. FLY NAVY!!!
The building which handles my data center actually still has some knob and tube in service, still in good shape. Maybe some day we will replace it. Then again we said that 10 years ago too.
@@renakunisaki Your question have two answers, yes and maybe. Yes as telegraph line indeed transfers date in form of dots and dashes or in binary if it is used for teletype service. Maybe if you had modern internet communication in mind. Old style lines don't have exactly the best inductance and capacitance parameters, but on limited length it is most likely possible.
Bought and lived in an old house in 1989. It had modern wiring but there were a couple of the old knobs in the basement. Now I've seen what the old system looks like.
dad and i rewired the house (built 1899) before i left for the marines. everything was on knobs as far as i remember. dirty works crawling through all those dusty spaces.
A couple years ago my childhood best friend and I inspected his (recently passed) grandparents' 1905 built home. The house had virtually no updating since being built. In addition to the K&T wiring, the outlets were mounted in the baseboards down at floor level and it had mercury filled push button light switches throughout. It had a screw-in fuse (4 of them!) circuit box. Everything still worked as designed, and probably would have kept on working but it needed (and got) completely gutted out and rebuilt.
Had this open wire in my mom and dad's house for years. As a kid with my brother involved in CB radio I always thought it was antenna wire. Until my Uncle dropped a test light over them and it worked. Needless when he found out the wires were live it was removed that night. But for 50 plus years it kept the lights on. On our front porch. Scary!
The house I grew up in was built in 1941. We had the ceramic round knobs in our attic. The wires had that woven fabric kind of material on the outside of it.
Many of the original Edison lightbulbs still work because the filament is much thicker than filament used in today's incandescent lightbulbs. That made them much less efficient (and bright) but far more durable. Interestingly, traffic lights of today (except for the LED ones) use a similar trick of thicker filament so that they don't need to be replaced very often, even though they use slightly more energy.
Is this why *LOW VOLTAGE* bulbs last so long, almost never burning out? Including for automobile taillights? I have 3V and 12V lights in the house that have been burning continuously about 20 years!
@@JungleYT This, but also some automotive lights are put through a tempering cycle to help them handle being on/hot. (at least the quality ones that most people buy and use.) House edison-style bulbs are not usually treated as much if at all and it's kind of expected and normalized that they'll quit in a year or two or three. Unfortunately it's true that if you make a perfect product you will make no money, and, if you make a good product that is only flawed in a slight way, you will sell a lot of them and people will come to expect the product to be imperfect.
@@KenzertYT Well, the 12V lamps I use in a small desk lamp are similar to auto tail light bulbs, and the 3Vs I use to illuminate a step might have a similar treatment having a "pilot light" utility? Low wattage bulbs, like 25W also have a higher resistance than say 100W bulbs, so that might be another relation. Still want to contact a lightbulb engineer at GE or something for explanation as well...
So this is a good video. Have a funny story. I do maintenance at some apartments in oakland and recently they did a seismic retrofit ordered by the city. Unfortunately one of the wires was damaged between 2 of the lights requiring the wire replaced. This building was built in like 69 after knob and tube was no longer allowed in New construction. The city inspector came and said that we had rewired everything without permits because this year building came with knob and tube wiring not romex wire. The owner is a close friend that I also look out for since her husband passed away so I called the city about it and told them what the inspector had said. They looked up the information on the building to confirm what I has said and sent a different inspector to check everything. Told him why some wire was replaced and he just looked to make sure the boxes were bonded to the ground and said good job you passed. First inspector was written up and made to attend some kind of training again. I'm not even a electrician and I know the basics.
Super video. Such a prevalent system even has a modern way to connect to it. By using a metal junction box, you can put ceramic tubes in for the knob and tube wires, and clamps or connectors for Romex or conduit. 💙 T.E.N.
The problem is as houses expanded, they simply added onto existing circuits. My kitchen is split into 3 breakers, which are shared by the living room ... 2 rooms away! I can't do anything electrical in the kitchen without messing up the TVs & computers in the living room. 2 outlets on the same wall are on 2 different circuits.
@@walterbrunswick Ecclesiastes 7:10 Do not say, “Why is it that the former days were better than these?” For it is not from wisdom that you ask about this.
I have ripped out the old stuff and install new, was a fire hazard insulation came off exposed wirings, these days it's all about speed and mass production unfortunately.
I still have this in my house, as someone who learned electrical wiring in 2018-19. I HATED replacing switches in my house, I was so irritated by no neutral wire and ground wire in every box. The breaker box is even more of a nightmare since multiple rooms are on the same breaker, my bedroom is on 3 different breakers.
@@gotioify I'm a person who doesn't like cutting corners when it's around safety. If money wasn't an issue, I would redo all the wiring, insulation, and plumbing in my house with my dad, bring the place upto code and then some. Like 15amp circuits would not run on 14AWG, but 12 AWG. I would go 1 level higher then needed just as an extra layer of safety since I'm a bit OCD when it comes to not having myself or my family injured.
I had my 1905 home remodeled and I saved some of the knob and tube as a display. It's funny how the main house was knob and tube, but the garage was stab lok . The garage was built in 1954. Both were updated, but I never realized how expensive electricians are.
@@skiumah06 The total cost was a little over 23k. It included a 200amp underground service for a 4,600 sqft. house, three car garage, adjacent workshop/gym and city permits. We trenched a city street to get to the pole. That by it self required additional permits, street closure fees and traffic control fees. The existing line did not meet current code so a new one had to be installed.
@@Jesse-gv9tf holy hell. We're looking at purchasing a 1900 home and had the inspection today. it "needs" some rewiring of knob and tube wiring and I'm just trying to get a sense of what it might cost. 1800 sqft. house, some of it is already rewired, but the entire upstairs is not.
@@skiumah06 my advice would be to schedule multiple electricians and have them submit bids. Remember, the lowest bid isn't always the best bid. I'm in Los Angeles, CA and prices here are ridiculous. The street trenching was shy of 9k by itself. I'm guessing you won't need to dig up the road and sidewalk so it might be considerably less expensive.
I have a modest collection od early Edison/G-E, Westinghouse incandescent carbon and early Tungsden light bulbs. I have a few Wert Dimmers as well. The Wert Dimmer when used with a 40 Watt light bulb which was the recommended wattage max for the dimmer, still heated up extensively, it felt like an iron. There was no limitations, their was no Underwriters Laboratories, and many homes burned down as a result.
My Grandparent's house built in 1900 had it (later removed, can still see the holes), and the 150 year old house I lived at in college STILL had active knob and tube in the basement when I left 12 years ago.
I'm a service electrician living in a 1936 home. Still has knob and tube wiring. Only real issue with it is that the insulation will begin to crack and leads to open copper in spots.
It wouldn't surprise me if Edison was the first to market porcelain insulators for use in lighting circuits, but he didn't come up with the idea; these were already in use when Thomas Edison was a child (back in the 1850s) - primarily on telegraph systems but also in electrical experiments alongside glass insulators. Just worth noting as a lot of people will interpret this video as "Edison invented porcelain insulators" just like many people think Edison invented the incandescent lightbulb. It's amazing to think that the first sets of wiring regulations/codes came out in the 1880s. What we call the "First Edition" of the wiring regulations in the UK was in place from 1882 (we're now on the 18th edition), and New York had regulations from 1881 (with the first US national code in 1897).
there is a house not far from were i live that was built in the early 1900s and was wired with knob and tube at the time it was built 4 years before power was run into our village they knew electricity was on its way and planed ahead as far as i know all of it is still in use today and in excellent condition along side with the modern wiring although all 4 original circuits were are arc fault protected with modern arc fault breakers a few years ago after the 60s 60 amp entrance was replaced
@@WalterKnox There is no ground, surge protectors will not work so you can't protect expensive electronics. Also, if a device was to short out the whole thing could be energized.
@@Aholeintheozone right, so if a device fails then it could be dangerous. Knob and tube is not dangerous, it was used for many years and ungrounded systems even longer. If you have an old house with K&T maybe run new circuits for the kitchen and where large appliances and stuff are and for electronics. But really for the most part it is fine and there is no reason to freak out like everyone does.
@@WalterKnox Walter, There certainly is a reason to freak out when a building (with today's power-hungry appliances in them) is wired with K&T. I've been an Electrician for 30 years and pulled out miles of this crap. In one building I worked in (which was a school for kids with special needs!) there was a roof leak and when the clean-up crew unknowingly plugged their dehumidifier into an outlet fed with K&T, they caught the attic on fire !!!! The reason was, the K&T had a shitty splice added to it years ago (VERY common problem) and the attic had been insulated with cellulose around the wires (another very common problem). K&T needs to breathe (as the old insulation sucks) to dissipate heat. When there is a bad connection and the wire can't dissipate heat, it is a recipe for disaster ! Hence the reason why insurance companies will not insure homes with K&T today. I won't even get into how bad K&T wires are degraded in fixture boxes, due to over-lamping over the last hundred years !!!
@@mattywho8485 like I mentioned before, it it HAS NOT been screwed with by idiots then it is fine, if it has been tapped into and messed with then it has to go, but originally it is fine. And believe it or not out here in the country where I am there are a bunch of little farm houses with original wiring that has not been messed with over the years.
Definitely an interesting demonstration. I've seen lots of K&T wiring, some still in good condition and service, but never have I seen those cleat things.
Just south of Edison’s Menlo Lab (in Metuchen, NJ) saw old house with a seemingly odd glass panel on an otherwise time-appropriate (old) wallpapered plaster-and-lath wall. It revealed the original knob and tube wiring as 1 of the first homes to be electrified.
Those cleets and knobs wiring looks almost exactly like what i found a couple of years ago in a cellar here in Germany. Still in proper working condition even with an original carbon fibre bulb, though way out of code since the end of WWII. But what do i care? I'm a plumber not an electrician. ;-) Edit, typo.
4:17 Holy smokes, a cutaway of a GE MS-5001 gas turbine unit. I worked on plenty of them all over the world. It doesn't have knobs but it had crossfire tubes.
I know a couple who had a house that was built early 1900's. He cut away part of a wall and put a picture frame with glass, his window to the past, showing the bare wire wiring system.
Iv'e seen these in old houses with no insulation on the wires. If you wanted to add a light or an outlet, you would just twist the wire to the line and tape it. You could attach a new circuit anywhere along the line. Kinda scary but cool at the same time.
Kevin W, it's probably ok to do this, but the wires should be soldered after they are twisted to the wires they are spliced to. Any corrosion would otherwise heat up the wrapped splice and eventually cause a fire, if the splice was not soldered.
cool stuff, I'm curious how the switch actually works.. And its really awesome they are getting this info put together while its still possible.. another 30 years and it would probably just have to be all from book and no first person stories.
My mother bought a houseboat in Seattle that had knob and tube wiring. Since she needed to upgrade the power to the house, she hired an electrician friend. He was perfectly willing to do the job, but he normally worked on commercial buildings, he rewired her houseboat to commercial code.
In Canada, back in the 70's, there was still a section in the electrical code on knob and tube wiring. It was in recognition that it was encountered in the field, and provided rules for repair and splicing into it. Others here have commented that rodents liked the insulation. I have never seen rodent damage to K & T. I have, however, seen the insulation eaten off the later paper and tar "Romex" cable - right down to the bare wire.
These arrays actually worked okay. One of the classic problems was people putting metal clothes hangers over the wires. Seemed like a convenient place to hang wash, but the insulation didn't hold up well over time.
Some years ago I had to go into the loft of an old country house here in the UK and the wiring in the loft was bare copper held in cleats some porcelain and others lignum vitae, this dated from when the house had its own low voltage DC lighting set but at some time in the past the mains was laid on (250 volts AC) the downstairs wiring was modernized but the loft was not but it had been connected to the rest of the house so that there was a lamp up there. I went straight don frm the loft and pulled the fuse before I would go up there again.
The history of electric power is fascinating. I shudder when I think of how insanely dangerous it must have been for them to be testing and learning things for the first time. No doubt electrocution and fires were common.
Retired from 45 years in the electrical trade, I live in a 1940 house that still has a little knob & tube upstairs. I’ve always felt it was designed to take aging and degradation of insulation into account. Properly installed knob & tube will work if all insulation falls off the wire and it’s bare, just don’t touch it! Knob & tube often fares well in floods, due to taking the “up and over” route, usually running in attics.
The last house my mom owned had knob & tube wiring in the attic. 1949 to today and no problems, but when I was young and had a reason to go into the attic I had to be very careful. I think I put some insulation up there.
The paper is used as a spacer/gap filler to keep the conductors from shifting or kinking when the cable is bent. The nylon/PVC jacket on the conductors is the actual insulation, although paper is a decent dielectric/insulator if used properly.
There's a place I have visited on the NY / PA border along the Delaware River that is now a campground but was once a grass airstrip. The original hanger still has this exposed wiring, although most is no longer in use. OTOH, last I looked the original fuse box was still hot. Up near the ceiling there are wires running the length of the building (at least 75 feet) kinda like a clothesline. It may have had more support at one time. These wires are about 10 feet apart and have the remnants of twisted connections, as if there may have been a series of suspended lights at one time. Guessing one is hot and the other is neutral, and you could just twist in another light fixture as needed, wherever you wanted. The reason I was there was to figure out how to disable those hanging wires. It wasn't too hard to follow them back to the panel and do away with the circuit, so nobody got hurt.
if you have an old house with knob and tube still intact leave it. if you want higher loads run a new electrical panel with new outlets and just leave the k&t for the already existing stuff like light fixtures. it is perfectly safe.
My parents bought a house in 1970 that was k&t since the early 1900's. The house was built in 1890. My dad installed a new panel and ran outlets to every room, eliminated the old k&t powered outlets, but kept all the ceiling fixtures on k&t. It worked perfectly fine, but was all completely rewired last year by an electrician who bought the house. It lasted nearly 50 years though like that without an issue.
@@njwags95 cloth covered BX wire is normally okay but if the cloth covering the wires is crumbling whenever slightly moved i would replace it because the 2 wires are so close together and in a metal tube so it would be a lot easier to short out than knob and tube, knob and tube has the wires far apart from each other and anything else, so even if it gets a bare spot it generally does not cause issues.
Walter Knox thanks for the info, it’s only safer that KT cause it’s grounded correct? Next week I’m opening up the ceiling and I know I’ll find some KT also. Not sure if I should swap out the BX.
@@njwags95 in most cases yes, it is only grounded if it uses all metal boxes and is all connected properly, but generally you will be okay, just dont overload it and it should be fine.
Selling our house that was built in the 1950’ an addition was added to the back of the house in the early 60’s. The inspector wrote that the knob & tube wiring needs to be replaced. 2 years ago when I bought the house this was never even mentioned. Must this be replaced??
I just went to look at a home and found out it had k&t after the inspection. Immediately terminated the agreement. 50-100k to pull the walls down and rewire the place, then put up new drywall. These are old homes too, so you may as well re-insulate and straighten out any structural issues while your walls are removed. People looking to buy could not afford a home that would not qualify for a mortgage.
*Knob and Tube = Bzzzzzzt!!!* Especially if the house was 80 - 100 years old and those wires sagged enough to touch from over-heating by modern appliance or broken insulators. In the daze of radio and lightbulbs, less of an issue. I still remember houses with thoze screw in fuses some people would sometimes replace with a penny, dime, etc. = Bzzzzzt, Fire!
i grew up in a house built in 1907 that had knob and tube wiring and there was nothing really wrong with it except that it was a 3-story house with a 60-amp service and only 1 or no wall outlets in each room.. the house also had no insulation in any of the walls, so we eventually replaced all of the wiring with romex and a 200-amp service with plenty of wall outlets everywhere and breakers instead of edison-base fuses which were getting hard and expensive to find. the insurance company was happier and the house was much more liveable afterwards.
Why didn't they want the wires touching the wood? Was it due to heat from the current? It couldn't have been too hot since he was touching it with his bear hand.
Knob and tube was very safe for it's day. The wires never come together except at the device. The drawback is the coating and the fact that joints were soldered together. I've found places where the joints between wires failed from the solder melting away.
Would the safest way to run wires be to run them like knob and tube but using proper connections and modern insulation, and having a third wire for earth? I can't help but think myself that keeping wires separate is safer.
Very nice presentation. Those antique bulbs should only be burned on reduced voltage though. There are only so many left, and once they're gone, they're gone forever. It also would be good to point out that knob and tube wiring is at least as safe as modern wiring, to dispel the myth (no doubt spread by unscrupulous electricians looking for work) that it should be replaced.
***** Rubbish! California and many other states have never seen a single fire caused by Knob and Tube wiring. Myself I would be more concerned by cloth covered romex!
EdwardsStation onSif Even the early thermoplastics found in 1950's and up cloth romex hold up very well, and should last for decades yet. But as with all types of wire, it's good to inspect in and around fixtures where incandescents have been used for years.
realvanman1 I believe the reason why knob and tube is so unsafe is because all the returning load was being put on one neutral. they could get away with running one neutral basement to attic and all the circuits through out the house connect to the same neutral at the easiest location . eventually neutral will have to much load and heat up and fatigue untill the point of broken wire or arc in the wall.
I'd imagine part of the risk involves people expanding K&T circuits far beyond the loads they were designed to handle. If it was so inherently under the loads of the day, I can't imagine it would have been nearly the prevalent standard it is remembered as today. Of course, it was designed for mostly lighting. No large AC units, no TV in each bedroom, no 800+ watt gaming PC's.
My light switch suddenly stopped working, found no voltage going to switch. All circuit breakers were still on, all lines out of panel box are romex. I went into attic to look for the line, it's knob and tube and the line had been electrical taped and it came apart. Live line was under insulation ugh...
Some of the insulation was asbestos, and would last forever. Mice love that rubber and fabric insulation. I lived in a house that had knob and tube insulation...one weird thing they did was put a fuse in both hot and neutral. If the neutral fuse blew, the light went out, but if you came into contact with live and ground, you'd know it. As long as you don't overload it ( by putting a 30 amp fuse in a 15 amp circuit, and the wiring isn't rotten, the knob and tube stuff is probably fine. One place I lived in back in the '80s was wired in 1922, and it was fine. Wall outlets had been added in the '30s. Originally, it was just wired for lights..
Scott Thomas, just as a precaution, I would locate every splice on K and T wiring, and check to see if each properly soldered. Redo, if necessary. Consider adding ground wires to every box where this circuit runs. This would help a lot. Every such installation I have seen uses 14 gauge wire. This must be fused to not more than 15 amps.
To place a ceiling light there was a 1×4 backer board between two joists laid flat with with 45 degree holes drilled next to and opposite each other to place the wires in, using pieces of loom to go through the board and lathe and plaster.
The house im in now has this type of wiring. The computer i'm using to post this message is running on power that goes through knob and tube style wiring.
The owners of Exxon in Asheville North Carolina had this wiring in their house and they had red horse hair insulation in the attic they also had the first air conditioner unit installed in North Carolina posh house .
@@Intelwinsbigly Hahah love that and am definitely stealing it, but still, most likely (99%) balloon framed house and it's gonna go up like a roman candle.
I have a question about knob and tube, and hoping someone here might have an answer! My house was built in 1925, and originally was all k&t. When it was refurbished in 1976, modern Romex replaced all the k&t, except for the the light over the staircase. That light and it's two switches were left untouched, for reasons unknown. When I replaced the light bulb with a CFL type, it burned out immediately. A second bulb did the same. LED bulbs burn out immediately as well. Regular incandescents work fine. I'm just wondering why this is. Someone once told me this could be due to a lack of a neutral wire, and that a single load wire passing through the incandescent bulb will make the filament glow normally. I don't know if this is true. Hope someone here can shed some light on this!
@@chrismc7205 it is AC not DC, reverse polarity will cause the hot and neutral to be reversed, but there is no positive and negative, so it will still work the same. and as for there being no neutral wire, there is a neutral wire, just not a ground. without a neutral there would be no current and no light.
First thing you need to do is look at the incandecent bulb you removed. Either printed on the top, or stamped along the screw just below the glass part there will be a rating. Most circuits in a house should be 120v however this may have been wire 240 volts. A 120v incandecent can work on 240 but a CFL or led will not. Go to the hardware store and buy a regular 240v 50 or 60watt incandecent bulb, if it glows full brightness in the socket the light was wired 240 volt. If 240v, you need to get an electrician to come change it to 120v. Diagnosing it yourself will save you some time and money with the electrician. However, if the bulb does not glow full brightness, there is something very suspicious going on, and an electrician will need to come cut holes in the wall and figure out what exactly is happening. Other than that there may be some other reason that I don't know of but someone else here may be able to help further.
I just ripped a ton of this stuff out of my house. Pennies jammed into the fuse panel, a excess of things tied intoa single circuit, what a fire hazard......
Each switch selects between hot and neutral, if the bulb gets two neutrals then there is no voltage across the bulb and it's off. If the bulb gets two hots then there is also no voltage across the bulb and it's also off. The bulb is only on if it gets one hot and one neutral. It's more dangerous than other systems for 3-way switching for two reasons. Firstly the bulb holder may be hot even with the light is off. Secondly the outer shell of the bulb holder may be hot. Thirdly if the switch is not designed for such use it may pull an arch between hot and neutral.
. Edison ran a DC system I believe.. Seems like for a while before a National Grid every power station had their own power values and that if two companies wanted to trade power they needed a set of Motor -Generators or Rotary transformers to convert to the others standard. 110 volt 25 cycle seemed to be the popular one when a national grid required a national standard until the early 1950s when 120vac 60 cycle became the standard.
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My grandfather worked for Penelec in PA, all his life and retired in`1965. When I was a kid, probably in 1967,68, I remember him telling me that after a heavy thunderstorm, back in the 1940s, someone called and said they were out of power. His crew went to the house and found power was available at the entrance. They went inside and there was no power. They started testing and found none of the knob and tube lines had power, he grabbed one of the wires and it fell apart, there was no copper in the insulation. They checked the whole house and most of the copper in the wires was vaporized by a lightning hit during the storm. The people needed to get their house totally rewired.
Wow, that must have made quite the noise when the house was hit
As a lineman for 25 years in a modern world I'm thankful for people like your grandfather who paved the way for us. I can just imagine him being called out. I also think about the first lineman who knew nothing and every death was a learning experience. Even though I didn't know him I can call him a brother.
I think the house needed rewiring before the lightening. The lightening would have destroyed any type of wiring so just a good push & justification for upgrade
😂 that’s crazy
I actually learned how to install knob and tube wiring when I was in vocational school in the 1960’s. I think it was just a way to introduce us to something we’d find out in the world, as well as to visualize circuits. Very cool.
My grandfather's two story house had this wiring. The first floor had wires to one leg the ceiling for the other leg. The ceiling of the second floor was the same leg in the floor of the first floor.
The basement my grandfather wired
It would be an excellent means for aiding in visulization of more modern equipment.
"They made things to last." What a concept, produce and use quality material and items and here a hundred years later they are still working just fine.
There is actually a big problem with the knob and tube insulation. The insulation, when repeatedly heated, becomes extremely brittle with time. You almost always see this around light fixtures. It is probably the reason why knob and tube is considered such a fire hazard. I’m guessing the insulation is also not very fire resistant.
@@Shastavalleyoutdoorsman The main thing that makes knob and tube dangerous is when people that don’t know what they’re doing try to modify it
@@TechHowden no the main thing that makes it dangerous is the coatings become decrepit and fall off leaving bare wires. I've seen it hundreds of times. I remodel houses for a living.
@@Shastavalleyoutdoorsman as long as the wires never touch it is not a problem .
“They made things to last” is a bit of a paradox. They also made things poorly back then, but those items didn’t last so we don’t see them anymore. Hence why people tend to associate old items in general with quality, even if it’s just a few select items that were built well.
In "my days" in HVAC/R service, "the boys" were installing a retrofit system in a very old farmhouse. I was up there installing the AC tubing/ controls and part of it was back in a closet against the roof pitch. One of the guys says "what's this wire here for?" BARE WIRE. One look and I grabbed my meter. YUP!!! Still live, still being used. BARE knob and tube This was about 1985-90-ish
Found one of those little surprises doing renovation work on my 1922 house. Wiring had been upgraded to modern standards, new breaker box, but an end of run on one circuit had the old knob and tube (same situation, tiny spot that was hard to get to). No bare wires, but the insulation had degraded so badly that it might as well have been bare. Luckily, even as a rookie DIY guy, I had the presence of mind to check with the meter. To say this got my immediate attention would be an understatement. About 1997. Kind of scary to think how many of these time bombs have been left by past electrical contractors or homeowners just waiting to start a fire or electrocute the unwary. Note, the only reason I discovered this was because I was taking out some of the old lath and plaster walls - had the plans been different that hazard could well be hiding in that house to this day.
@@murraystewartj Anyone who looks at something like this and thinks "It's fine to touch this" kind of deserves it.
@@Intelwinsbigly Well I think that's a bit harsh, since not everyone (talking homeowners here) might not recognize it for what it is, and may encounter it when not intending to do electrical work at all. I'm willing to forgive ignorance to a point, but never out and out risky stupidity. I learned my lesson at 5 years of age by sticking a metal object into an outlet, so I have a healthy respect for what electricity can do and always test and retest anything I encounter, lockout, retest, then get to work. And I've learned never to trust someone else's work but to verify for myself.
I remember my great grandmother’s house had this type of wiring around 1960. The house was built around 1890 something. There was a hand water pump at the kitchen sink, and a cistern outside to catch rainwater from the roof. The cistern was divided through the middle by a wall of brick, two bricks thick. The water came into one side, and the brick wall acted as a filter. The water was drawn out from the opposite side from where it entered. The house had lathe and plaster walls. When she passed away, the relative who inherited the house had it gutted and brought it up to code.
I was born in 1986 and the house we lived in had this knob and tube wiring. My father sold the house around 1996 as I recall. Also had lath and plaster walls.
@Alexthefancollector Walker It's the cult of modernity. It seeks only consumption and later destruction.
@@Melanie16040 i read that carpenters hated nailing all those strips to the wall for plastering .
Superb and simple explanation of early wiring technology - have seen it many times. My dear old dad was an electrician - finished his apprenticeship at Standard Telephones in England in 1919. After a spell in the British Army in India (1921-1933) in 1933 was employed by the Mount Royal hotel in London until his retirement in 1980 - having worked as ‘sparkie’ for 47 years. Electricity in all its forms is maybe the greatest modern invention.
Plumbing and electric service IS civilization in my opinion. People take this stuff for granted.
I grew up in a Philadelphia rowhouse, the third floor was never rewired, it still had the original tube and knob, their was a junction under the floorboard in the hallway on the third floor,it looked as good as the day it was installed. However, my house was built in 1900, and wired in 1911 for electricity, according to the city records that I found in city hall. The city back then required that any modifications made to a pre existing property needed to be doccumented.
My grandparents had a home from the late 1800's that originally has gas lines running through the walls for gas lamp lighting.
My parents bought a tenement flat in Glasgow in 1961 and there was still gas lighting in the hall and sitting room. The gas lines were still in the walls of the other rooms, the previous owners had removed the light units and just closed off the gas supply to the rooms.
I got a rock
As a carpenter I would run into them on older residential remodels
My friends house was built with gas lighting and when electricity came around they ran the wires through the gas lines like they were conduit.
Many of the older public buildings (including schools) here contain remnants of gaslights.
Knob depth of 1" was good at keeping blind screws at bay too. Pound a nail in a wall to hang a picture. Boom. It was also nice to see the layout work, with both the hot and neutral running in the same void (plenums) between studs and trusses, but at the same time opposite each other on different studs. Professional electricians at the time, always kept the hot on one side, (I believe it was north or west), consistently throughout the house for reference
My old bungalow had hot wires in the ceilings and neutrals in the floors. Electrical receptacles had a wire of single conductor going down and a single conductor going up. Lights were similar, a wire from the ceiling to a bulb, then to a switch, then through the floor. Nothing ever backtracked... and that was 1940s.
@@mgjk Wow, that is interesting -- I never knew any houses were wired that way.
as an electrician from 1967 to 1995 i've done a lot of work on knob & tube wiring. if it is left alone & not "messed with " it is perfectly safe, however, this is rarely the case. i spent a lot of time re-wiring buildings to remove knob & tube for nervous insurance agents & homeowners. my house was built in 1906 with knob & tube. i sleep just fine. from 1995 to 2017 i was a electrical safety inspector for a major ohio city. better inspecting than working on. most of the time needlessly. if knob & tube is inherently flawed, most of the houses in oakwood, ohio would have burned to the ground years ago.
I'm an electrician in Dayton, OH, started back in 2003, residential new construction and service. I hated working in Oakwood (damn Jenkins) with their city reality presale inspections and the large amounts of K&T that's still there. Have twice run into that hideous "Carter" or "California" Threeway as well down there. I concur on the "leave it alone". Once you start touching it, it crumbles away. Did you know any of the Mont. County inspectors? Bobby Spencer that passed, Gale, Neal? I've lost touch with who is out there now, after going to be a nameless Mook for commercial companies.
@@Salty_Balls if k & t insulation crumbles when touched, it should be replaced, probably from being overfused in the past. jenkins does not wok for oakwood, just does electrical inspections. oakwood does their own pre-sale inspections. knew all the inspectors you mentioned.
@@garybrown7044 If it was inside a box, we just heat shrinked it with tubing and then taped it (was usually just a service call situation). Outside a box, wouldn't touch it period unless it was to remove. I just hate Jenkins, as a general comment, add Neal to that, and the whole city of Oakwood. Never been a worse bunch of homeowners then that town. That city needs an enema. Ever bump into a guy named Jerry Deischer? One eye, big old drinker nose, tough as nails, a little scary? He's been dead awhile now, 8 years or so, but he was around a long time, not as long as Sheriff though.
I save knob and tube joints and look at the connections when i eliminate it.most folks dont realize(the joints are soldered). I agree if knob and tube isnt messed with or overloaded,it's fine for the most part.
@@benbradshawjr2856 my grandfather installed knob & tube before ww-1 & after until approx.1932. i still have his soldering "copper" & gasoline fired blowtorch. he drilled holes by hand. he bought solder in 5 lb. spools.
Even today, where K&T is frowned on and frequently removed when encountered, it generally works well as long as you NEVER TOUCH IT. As a service guy, I hated opening a box up and moving the old wiring around. As long as it just sits there and isn't moved it's really not an issue usually. But when you move K&T around, you find that as it moves the rubber insulation crumbles away and the woven sheath falls apart, leaving the conductor bare. Had to many a times apply heat shrink tubing back over the conductors to give it some form of insulation again. Best to leave it be if at all possible.
It’s mostly frowned upon by the Insurance Industry, due to losses. And it’s frowned upon by the BuildingOwner when they are told by the Insurance company to upgrade or no Insurance. Lol.
The house I grew up in had the remnants on knob and tube but had been “upgraded” to the two wire, tar and cloth cornered cable.... like Romex, but worse.
Tube and knob was a well engineered concept of wiring, the wiring itself stood the test of time, it was Nickel wire covered in rubber then cloth wrapped, and then placed in a loose casing of burlap tubing, I have seen where rodents ate this insulation, this caused numerous fires back in the day im sure. Great piece! I will subscribe.
Many years ago , We rented a house that was all knob and tube , and our electric bill was around $16.00 a month . that was in the eighties .
Was that a good price for the time? (I wasn't alive then, and we can't compare to modern bills of 500 AUD+ !)
@@briannem.6787 It is equivalent to $40 in today's price
Back in the 60's my grandfather dynamited stumps to clear a part of a field. In the 70's ( after he died ) they found his stash. 3 sticks and blasting caps wedged between the sealing and the wiring of an old shed. Yes it was safely removed.
As a side note.....Yes it was fun watching the stumps go up into the air. Down side was cleaning up the mess.
If only we could return to the times when people had access to the fun stuff.
The march of the statists continues.
Working on a bathroom renovation in Hewlett- New York about two years ago, 2019, saw knob and tube wiring running to the attic. Was told not to worry it was all in disuse for years. Put my tick to it, yep,still live running the attic light.
My daughters house in Patchogue New York, around , five years ago, 2016, when the sheet rock was removed on the second floor, found the knob and tube tied into the Romex wiring behind the walls
I remember the nobs and tubes but the wires in our old house had almost no insulation left on them. Dad replaced them as he could but they were there long enough for we kids had plenty of time to find them in the attic as we explored our first home.
My family had a house that was built in 1903 at least that's the only records we could find of it. It had knob and tube wiring that still worked in the 1970's. The house also had a barn in the back yard with spots for 2 carriages and two horses with quarters for a stable boy above it. FLY NAVY!!!
The building which handles my data center actually still has some knob and tube in service, still in good shape. Maybe some day we will replace it. Then again we said that 10 years ago too.
If its in good shape is safe.
@@Tadfafty There is perhaps not much that can go wrong and even if primary insulation will decay the porcelain should prevent problems.
Does the data travel through telegraph lines?
@@renakunisaki Your question have two answers, yes and maybe.
Yes as telegraph line indeed transfers date in form of dots and dashes or in binary if it is used for teletype service.
Maybe if you had modern internet communication in mind. Old style lines don't have exactly the best inductance and capacitance parameters, but on limited length it is most likely possible.
@@renakunisaki Lol, you walked into that one.
Praise be to the mighty algorithm for bringing me to this video from eight years ago. Many thanks given oh mighty algorithm! The video was enjoyed.
Bought and lived in an old house in 1989. It had modern wiring but there were a couple of the old knobs in the basement. Now I've seen what the old system looks like.
dad and i rewired the house (built 1899) before i left for the marines. everything was on knobs as far as i remember. dirty works crawling through all those dusty spaces.
Old switches were soo cool
A couple years ago my childhood best friend and I inspected his (recently passed) grandparents' 1905 built home. The house had virtually no updating since being built. In addition to the K&T wiring, the outlets were mounted in the baseboards down at floor level and it had mercury filled push button light switches throughout. It had a screw-in fuse (4 of them!) circuit box. Everything still worked as designed, and probably would have kept on working but it needed (and got) completely gutted out and rebuilt.
"mercury filled push button light switches throughout." Words can not describe the jealousy.
Had this open wire in my mom and dad's house for years. As a kid with my brother involved in CB radio I always thought it was antenna wire. Until my Uncle dropped a test light over them and it worked. Needless when he found out the wires were live it was removed that night. But for 50 plus years it kept the lights on. On our front porch. Scary!
The house I grew up in was built in 1941. We had the ceramic round knobs in our attic. The wires had that woven fabric kind of material on the outside of it.
Wow, I my dad owned a house in Fernandina, Beach that was filled with this knob and tube. He has since sold the place.
This comment section is a goldmine of history! :3
Love to see old technology like this, too! My fingers tingle just looking at it, but it's beautiful!
So informative! Never knew what these porcelain pieces were for!!!
I know this video is over 100 years old. But it’s pretty good. Very informative.
What year do you live in?
Devin Harris 2019. The vid was recorded in 1919. 🙄
I worked on stuff older than that in Chicago; conduit made with bare wires laid in grooved lumber with a slat nailed over the top!
fascinating. I still have the glass cabinet fuseboard from my gran's home.
Many of the original Edison lightbulbs still work because the filament is much thicker than filament used in today's incandescent lightbulbs. That made them much less efficient (and bright) but far more durable. Interestingly, traffic lights of today (except for the LED ones) use a similar trick of thicker filament so that they don't need to be replaced very often, even though they use slightly more energy.
Is this why *LOW VOLTAGE* bulbs last so long, almost never burning out? Including for automobile taillights? I have 3V and 12V lights in the house that have been burning continuously about 20 years!
@@JungleYT Very likely, yes.
@@JungleYT This, but also some automotive lights are put through a tempering cycle to help them handle being on/hot. (at least the quality ones that most people buy and use.) House edison-style bulbs are not usually treated as much if at all and it's kind of expected and normalized that they'll quit in a year or two or three. Unfortunately it's true that if you make a perfect product you will make no money, and, if you make a good product that is only flawed in a slight way, you will sell a lot of them and people will come to expect the product to be imperfect.
@@KenzertYT Well, the 12V lamps I use in a small desk lamp are similar to auto tail light bulbs, and the 3Vs I use to illuminate a step might have a similar treatment having a "pilot light" utility? Low wattage bulbs, like 25W also have a higher resistance than say 100W bulbs, so that might be another relation. Still want to contact a lightbulb engineer at GE or something for explanation as well...
So this is a good video. Have a funny story. I do maintenance at some apartments in oakland and recently they did a seismic retrofit ordered by the city. Unfortunately one of the wires was damaged between 2 of the lights requiring the wire replaced. This building was built in like 69 after knob and tube was no longer allowed in New construction. The city inspector came and said that we had rewired everything without permits because this year building came with knob and tube wiring not romex wire. The owner is a close friend that I also look out for since her husband passed away so I called the city about it and told them what the inspector had said. They looked up the information on the building to confirm what I has said and sent a different inspector to check everything. Told him why some wire was replaced and he just looked to make sure the boxes were bonded to the ground and said good job you passed. First inspector was written up and made to attend some kind of training again. I'm not even a electrician and I know the basics.
Most inspectors where I live are jackasses who just want to fine.
City needs mo money fo mo handouts I guess.
Super video. Such a prevalent system even has a modern way to connect to it. By using a metal junction box, you can put ceramic tubes in for the knob and tube wires, and clamps or connectors for Romex or conduit. 💙 T.E.N.
the house i'm living in, and running this computer off of is useing knob and tube, love that method tbh.
Same!
The problem is as houses expanded, they simply added onto existing circuits. My kitchen is split into 3 breakers, which are shared by the living room ... 2 rooms away! I can't do anything electrical in the kitchen without messing up the TVs & computers in the living room. 2 outlets on the same wall are on 2 different circuits.
@@theTeslaFalcon but what are you complaining about? things were better in the good old days!!! 🤣
@@walterbrunswick
Ecclesiastes 7:10
Do not say, “Why is it that the former days were better than these?”
For it is not from wisdom that you ask about this.
The house I'm working on now is loaded with it.
Ditto. My bedroom light switch is that turn dial.
@@theTeslaFalcon poor poor little boy
I have ripped out the old stuff and install new, was a fire hazard insulation came off exposed wirings, these days it's all about speed and mass production unfortunately.
@@spearvlogs8347 Also have a rotary light switch in my bedroom. It's just as good as any other type of switch.
I still have this in my house, as someone who learned electrical wiring in 2018-19. I HATED replacing switches in my house, I was so irritated by no neutral wire and ground wire in every box. The breaker box is even more of a nightmare since multiple rooms are on the same breaker, my bedroom is on 3 different breakers.
The place I live in was a woodshop that was added onto and made into a house. Our wiring is in the same state. It's insane.
@@gotioify I'm a person who doesn't like cutting corners when it's around safety. If money wasn't an issue, I would redo all the wiring, insulation, and plumbing in my house with my dad, bring the place upto code and then some. Like 15amp circuits would not run on 14AWG, but 12 AWG. I would go 1 level higher then needed just as an extra layer of safety since I'm a bit OCD when it comes to not having myself or my family injured.
Here, over a hundred years later, one thing hasn't changed. Electricians still sit around in chairs discussing work rather then doing it.
I had my 1905 home remodeled and I saved some of the knob and tube as a display. It's funny how the main house was knob and tube, but the garage was stab lok . The garage was built in 1954. Both were updated, but I never realized how expensive electricians are.
how much did it cost you to get it rewired?
@@skiumah06 The total cost was a little over 23k. It included a 200amp underground service for a 4,600 sqft. house, three car garage, adjacent workshop/gym and city permits. We trenched a city street to get to the pole. That by it self required additional permits, street closure fees and traffic control fees. The existing line did not meet current code so a new one had to be installed.
@@Jesse-gv9tf holy hell. We're looking at purchasing a 1900 home and had the inspection today. it "needs" some rewiring of knob and tube wiring and I'm just trying to get a sense of what it might cost. 1800 sqft. house, some of it is already rewired, but the entire upstairs is not.
@@skiumah06 my advice would be to schedule multiple electricians and have them submit bids. Remember, the lowest bid isn't always the best bid. I'm in Los Angeles, CA and prices here are ridiculous. The street trenching was shy of 9k by itself. I'm guessing you won't need to dig up the road and sidewalk so it might be considerably less expensive.
@@skiumah06 michigan?
I have a modest collection od early Edison/G-E, Westinghouse incandescent carbon and early Tungsden light bulbs. I have a few Wert Dimmers as well. The Wert Dimmer when used with a 40 Watt light bulb which was the recommended wattage max for the dimmer, still heated up extensively, it felt like an iron. There was no limitations, their was no Underwriters Laboratories, and many homes burned down as a result.
My Grandparent's house built in 1900 had it (later removed, can still see the holes), and the 150 year old house I lived at in college STILL had active knob and tube in the basement when I left 12 years ago.
I'm a service electrician living in a 1936 home. Still has knob and tube wiring. Only real issue with it is that the insulation will begin to crack and leads to open copper in spots.
It wouldn't surprise me if Edison was the first to market porcelain insulators for use in lighting circuits, but he didn't come up with the idea; these were already in use when Thomas Edison was a child (back in the 1850s) - primarily on telegraph systems but also in electrical experiments alongside glass insulators. Just worth noting as a lot of people will interpret this video as "Edison invented porcelain insulators" just like many people think Edison invented the incandescent lightbulb.
It's amazing to think that the first sets of wiring regulations/codes came out in the 1880s. What we call the "First Edition" of the wiring regulations in the UK was in place from 1882 (we're now on the 18th edition), and New York had regulations from 1881 (with the first US national code in 1897).
there is a house not far from were i live that was built in the early 1900s and was wired with knob and tube at the time it was built 4 years before power was run into our village they knew electricity was on its way and planed ahead as far as i know all of it is still in use today and in excellent condition along side with the modern wiring although all 4 original circuits were are arc fault protected with modern arc fault breakers a few years ago after the 60s 60 amp entrance was replaced
And if you buy a house with knob and tube, the insurance companies will freak out and may refuse to insure it until it's upgraded.
sad really, it is a great system and if in good shape there really is no need to replace it.
@@WalterKnox There is no ground, surge protectors will not work so you can't protect expensive electronics. Also, if a device was to short out the whole thing could be energized.
@@Aholeintheozone right, so if a device fails then it could be dangerous. Knob and tube is not dangerous, it was used for many years and ungrounded systems even longer. If you have an old house with K&T maybe run new circuits for the kitchen and where large appliances and stuff are and for electronics. But really for the most part it is fine and there is no reason to freak out like everyone does.
@@WalterKnox Walter, There certainly is a reason to freak out when a building (with today's power-hungry appliances in them) is wired with K&T. I've been an Electrician for 30 years and pulled out miles of this crap. In one building I worked in (which was a school for kids with special needs!) there was a roof leak and when the clean-up crew unknowingly plugged their dehumidifier into an outlet fed with K&T, they caught the attic on fire !!!! The reason was, the K&T had a shitty splice added to it years ago (VERY common problem) and the attic had been insulated with cellulose around the wires (another very common problem). K&T needs to breathe (as the old insulation sucks) to dissipate heat. When there is a bad connection and the wire can't dissipate heat, it is a recipe for disaster ! Hence the reason why insurance companies will not insure homes with K&T today. I won't even get into how bad K&T wires are degraded in fixture boxes, due to over-lamping over the last hundred years !!!
@@mattywho8485 like I mentioned before, it it HAS NOT been screwed with by idiots then it is fine, if it has been tapped into and messed with then it has to go, but originally it is fine. And believe it or not out here in the country where I am there are a bunch of little farm houses with original wiring that has not been messed with over the years.
Definitely an interesting demonstration. I've seen lots of K&T wiring, some still in good condition and service, but never have I seen those cleat things.
Just south of Edison’s Menlo Lab (in Metuchen, NJ) saw old house with a seemingly odd glass panel on an otherwise time-appropriate (old) wallpapered plaster-and-lath wall. It revealed the original knob and tube wiring as 1 of the first homes to be electrified.
Those cleets and knobs wiring looks almost exactly like what i found a couple of years ago in a cellar here in Germany. Still in proper working condition even with an original carbon fibre bulb, though way out of code since the end of WWII. But what do i care? I'm a plumber not an electrician. ;-)
Edit, typo.
Wow they used to use a lot of porcelain back in the day. Looks like plumbers toilets weren’t the only items using the stuff.
Porcelain is good stuff, lasts for centuries.
4:17 Holy smokes, a cutaway of a GE MS-5001 gas turbine unit. I worked on plenty of them all over the world. It doesn't have knobs but it had crossfire tubes.
I know a couple who had a house that was built early 1900's. He cut away part of a wall and put a picture frame with glass, his window to the past, showing the bare wire wiring system.
Iv'e seen these in old houses with no insulation on the wires. If you wanted to add a light or an outlet, you would just twist the wire to the line and tape it. You could attach a new circuit anywhere along the line. Kinda scary but cool at the same time.
When it was just light bulbs and a radio, no problem...
Kevin W, it's probably ok to do this, but the wires should be soldered after they are twisted to the wires they are spliced to. Any corrosion would otherwise heat up the wrapped splice and eventually cause a fire, if the splice was not soldered.
@@jeromewysocki8809 Honestly, this set up sounds like a dream.
My house still has this type of wiring in parts of if and is in use daily and is running everything just fine .
Yeah it's safe for radios lamps just stuff they use to have back in the day. No microwaves or other modern appliances
I have actually worked on this stuff in my early years as an electrician
Worked on this stuff last month, here in Pennsylvania TONS of houses still have knob and tube wiring, it's VERY common.
cool stuff, I'm curious how the switch actually works.. And its really awesome they are getting this info put together while its still possible.. another 30 years and it would probably just have to be all from book and no first person stories.
My mother bought a houseboat in Seattle that had knob and tube wiring. Since she needed to upgrade the power to the house, she hired an electrician friend. He was perfectly willing to do the job, but he normally worked on commercial buildings, he rewired her houseboat to commercial code.
In Canada, back in the 70's, there was still a section in the electrical code on knob and tube wiring. It was in recognition that it was encountered in the field, and provided rules for repair and splicing into it. Others here have commented that rodents liked the insulation. I have never seen rodent damage to K & T. I have, however, seen the insulation eaten off the later paper and tar "Romex" cable - right down to the bare wire.
Don't understand why we cant just lace the insulation with poison.
Arsenic and mercury oxides wouldn't go airborne in a fire, would be fine.
@@Intelwinsbigly Arsenic and mercury laced insulation would be a health hazard during manufacture and installation.
These arrays actually worked okay. One of the classic problems was people putting metal clothes hangers over the wires. Seemed like a convenient place to hang wash, but the insulation didn't hold up well over time.
My grandfather’s cottage still has this wiring in use in the original part.
I love old construction materials
Some years ago I had to go into the loft of an old country house here in the UK and the wiring in the loft was bare copper held in cleats some porcelain and others lignum vitae, this dated from when the house had its own low voltage DC lighting set but at some time in the past the mains was laid on (250 volts AC) the downstairs wiring was modernized but the loft was not but it had been connected to the rest of the house so that there was a lamp up there. I went straight don frm the loft and pulled the fuse before I would go up there again.
The history of electric power is fascinating. I shudder when I think of how insanely dangerous it must have been for them to be testing and learning things for the first time. No doubt electrocution and fires were common.
very cool, thanks for the video, I have knob and tube and trying to figure out what goes into rewiring, video was very helpful
solder and flux if your going to add onto it
Retired from 45 years in the electrical trade, I live in a 1940 house that still has a little knob & tube upstairs. I’ve always felt it was designed to take aging and degradation of insulation into account. Properly installed knob & tube will work if all insulation falls off the wire and it’s bare, just don’t touch it! Knob & tube often fares well in floods, due to taking the “up and over” route, usually running in attics.
I own a farm shop that still uses open knob and tube. It's actually pretty safe as long as no one disturbs it or stacks things on top of it.
The last house my mom owned had knob & tube wiring in the attic. 1949 to today and no problems, but when I was young and had a reason to go into the attic I had to be very careful. I think I put some insulation up there.
The paper is used as a spacer/gap filler to keep the conductors from shifting or kinking when the cable is bent. The nylon/PVC jacket on the conductors is the actual insulation, although paper is a decent dielectric/insulator if used properly.
Knob and tube wiring is still covered in the NEC. ARTICLE 394.
There's a place I have visited on the NY / PA border along the Delaware River that is now a campground but was once a grass airstrip. The original hanger still has this exposed wiring, although most is no longer in use. OTOH, last I looked the original fuse box was still hot. Up near the ceiling there are wires running the length of the building (at least 75 feet) kinda like a clothesline. It may have had more support at one time. These wires are about 10 feet apart and have the remnants of twisted connections, as if there may have been a series of suspended lights at one time. Guessing one is hot and the other is neutral, and you could just twist in another light fixture as needed, wherever you wanted. The reason I was there was to figure out how to disable those hanging wires. It wasn't too hard to follow them back to the panel and do away with the circuit, so nobody got hurt.
i got really into this and i clicked on it by mistake. thanks for the video
if you have an old house with knob and tube still intact leave it. if you want higher loads run a new electrical panel with new outlets and just leave the k&t for the already existing stuff like light fixtures. it is perfectly safe.
My parents bought a house in 1970 that was k&t since the early 1900's. The house was built in 1890. My dad installed a new panel and ran outlets to every room, eliminated the old k&t powered outlets, but kept all the ceiling fixtures on k&t. It worked perfectly fine, but was all completely rewired last year by an electrician who bought the house. It lasted nearly 50 years though like that without an issue.
How about cloth covered BX wire?
@@njwags95 cloth covered BX wire is normally okay but if the cloth covering the wires is crumbling whenever slightly moved i would replace it because the 2 wires are so close together and in a metal tube so it would be a lot easier to short out than knob and tube, knob and tube has the wires far apart from each other and anything else, so even if it gets a bare spot it generally does not cause issues.
Walter Knox thanks for the info, it’s only safer that KT cause it’s grounded correct? Next week I’m opening up the ceiling and I know I’ll find some KT also. Not sure if I should swap out the BX.
@@njwags95 in most cases yes, it is only grounded if it uses all metal boxes and is all connected properly, but generally you will be okay, just dont overload it and it should be fine.
my nephew still finds this in his renovation jobs to this day. It's nightmarish. Many fires have been caused by this stuff being left in service.
Selling our house that was built in the 1950’ an addition was added to the back of the house in the early 60’s. The inspector wrote that the knob & tube wiring needs to be replaced. 2 years ago when I bought the house this was never even mentioned. Must this be replaced??
I just went to look at a home and found out it had k&t after the inspection. Immediately terminated the agreement. 50-100k to pull the walls down and rewire the place, then put up new drywall. These are old homes too, so you may as well re-insulate and straighten out any structural issues while your walls are removed. People looking to buy could not afford a home that would not qualify for a mortgage.
@@dylancooper8497 come to find out it was the real estate agent was the person who mentioned K&T in the house. There was no K&T..🙄🤦♂️
*Knob and Tube = Bzzzzzzt!!!* Especially if the house was 80 - 100 years old and those wires sagged enough to touch from over-heating by modern appliance or broken insulators. In the daze of radio and lightbulbs, less of an issue. I still remember houses with thoze screw in fuses some people would sometimes replace with a penny, dime, etc. = Bzzzzzt, Fire!
i grew up in a house built in 1907 that had knob and tube wiring and there was nothing really wrong with it except that it was a 3-story house with a 60-amp service and only 1 or no wall outlets in each room.. the house also had no insulation in any of the walls, so we eventually replaced all of the wiring with romex and a 200-amp service with plenty of wall outlets everywhere and breakers instead of edison-base fuses which were getting hard and expensive to find. the insurance company was happier and the house was much more liveable afterwards.
A good post, ive run into knob and tubing wiring, years go.
Why didn't they want the wires touching the wood?
Was it due to heat from the current?
It couldn't have been too hot since he was touching it with his bear hand.
Knob and tube was very safe for it's day. The wires never come together except at the device. The drawback is the coating and the fact that joints were soldered together. I've found places where the joints between wires failed from the solder melting away.
Would the safest way to run wires be to run them like knob and tube but using proper connections and modern insulation, and having a third wire for earth? I can't help but think myself that keeping wires separate is safer.
Very important for the insulators being glass to be reused after the fire!
Very nice presentation.
Those antique bulbs should only be burned on reduced voltage though. There are only so many left, and once they're gone, they're gone forever.
It also would be good to point out that knob and tube wiring is at least as safe as modern wiring, to dispel the myth (no doubt spread by unscrupulous electricians looking for work) that it should be replaced.
***** Rubbish! California and many other states have never seen a single fire caused by Knob and Tube wiring. Myself I would be more concerned by cloth covered romex!
EdwardsStation onSif Even the early thermoplastics found in 1950's and up cloth romex hold up very well, and should last for decades yet.
But as with all types of wire, it's good to inspect in and around fixtures where incandescents have been used for years.
realvanman1 I believe the reason why knob and tube is so unsafe is because all the returning load was being put on one neutral. they could get away with running one neutral basement to attic and all the circuits through out the house connect to the same neutral at the easiest location . eventually neutral will have to much load and heat up and fatigue untill the point of broken wire or arc in the wall.
The entire house I live in is knob and tube still. No fire yet, with over a hundred years of use. (Just don't tell my insurance company) :P
I'd imagine part of the risk involves people expanding K&T circuits far beyond the loads they were designed to handle. If it was so inherently under the loads of the day, I can't imagine it would have been nearly the prevalent standard it is remembered as today. Of course, it was designed for mostly lighting. No large AC units, no TV in each bedroom, no 800+ watt gaming PC's.
My house still has this set up
My light switch suddenly stopped working, found no voltage going to switch. All circuit breakers were still on, all lines out of panel box are romex. I went into attic to look for the line, it's knob and tube and the line had been electrical taped and it came apart. Live line was under insulation ugh...
I actually have 4 way key switch in my electrical box, as well as a 15 amp knife switch
Some of the insulation was asbestos, and would last forever. Mice love that rubber and fabric insulation. I lived in a house that had knob and tube insulation...one weird thing they did was put a fuse in both hot and neutral. If the neutral fuse blew, the light went out, but if you came into contact with live and ground, you'd know it.
As long as you don't overload it ( by putting a 30 amp fuse in a 15 amp circuit, and the wiring isn't rotten, the knob and tube stuff is probably fine.
One place I lived in back in the '80s was wired in 1922, and it was fine. Wall outlets had been added in the '30s. Originally, it was just wired for lights..
Scott Thomas, just as a precaution, I would locate every splice on K and T wiring, and check to see if each properly soldered. Redo, if necessary. Consider adding ground wires to every box where this circuit runs. This would help a lot. Every such installation I have seen uses 14 gauge wire. This must be fused to not more than 15 amps.
To place a ceiling light there was a 1×4 backer board between two joists laid flat with with 45 degree holes drilled next to and opposite each other to place the wires in, using pieces of loom to go through the board and lathe and plaster.
I know homes this still exists and operable. Made to last for sure.
The house im in now has this type of wiring. The computer i'm using to post this message is running on power that goes through knob and tube style wiring.
The owners of Exxon in Asheville North Carolina had this wiring in their house and they had red horse hair insulation in the attic they also had the first air conditioner unit installed in North Carolina posh house .
The building I live in now was knob and tube. There's still some in use but it's mostly been replaced with romex and 14/3 wiring.
cool but very dangerous
@@johnny6071 Danger is good for cleaning the gene pool.
@@Intelwinsbigly Hahah love that and am definitely stealing it, but still, most likely (99%) balloon framed house and it's gonna go up like a roman candle.
I have a question about knob and tube, and hoping someone here might have an answer! My house was built in 1925, and originally was all k&t. When it was refurbished in 1976, modern Romex replaced all the k&t, except for the the light over the staircase. That light and it's two switches were left untouched, for reasons unknown. When I replaced the light bulb with a CFL type, it burned out immediately. A second bulb did the same. LED bulbs burn out immediately as well. Regular incandescents work fine. I'm just wondering why this is. Someone once told me this could be due to a lack of a neutral wire, and that a single load wire passing through the incandescent bulb will make the filament glow normally. I don't know if this is true. Hope someone here can shed some light on this!
May be reverse polarity. Incandescent bulbs don’t care about polarity, leds and cfls do
@@chrismc7205 it is AC not DC, reverse polarity will cause the hot and neutral to be reversed, but there is no positive and negative, so it will still work the same. and as for there being no neutral wire, there is a neutral wire, just not a ground. without a neutral there would be no current and no light.
First thing you need to do is look at the incandecent bulb you removed. Either printed on the top, or stamped along the screw just below the glass part there will be a rating. Most circuits in a house should be 120v however this may have been wire 240 volts. A 120v incandecent can work on 240 but a CFL or led will not. Go to the hardware store and buy a regular 240v 50 or 60watt incandecent bulb, if it glows full brightness in the socket the light was wired 240 volt. If 240v, you need to get an electrician to come change it to 120v. Diagnosing it yourself will save you some time and money with the electrician. However, if the bulb does not glow full brightness, there is something very suspicious going on, and an electrician will need to come cut holes in the wall and figure out what exactly is happening. Other than that there may be some other reason that I don't know of but someone else here may be able to help further.
I just ripped a ton of this stuff out of my house. Pennies jammed into the fuse panel, a excess of things tied intoa single circuit, what a fire hazard......
great video...very informative
Can you properly explain or show an accurate drawing on how the CARTER SYSTEM works
Thank you
Each switch selects between hot and neutral, if the bulb gets two neutrals then there is no voltage across the bulb and it's off. If the bulb gets two hots then there is also no voltage across the bulb and it's also off. The bulb is only on if it gets one hot and one neutral.
It's more dangerous than other systems for 3-way switching for two reasons. Firstly the bulb holder may be hot even with the light is off. Secondly the outer shell of the bulb holder may be hot. Thirdly if the switch is not designed for such use it may pull an arch between hot and neutral.
Thank you for the video.
Early? It was still in my old basement when I moved out in 2005. haha. Fire inspector came by once and swore by it though for what it was.
still the best today
Very concise and well explained
Was the porcelainot meanto insulate *bare* copper wires?? Otherwise, if insulated, why keep them separated?
. Edison ran a DC system I believe.. Seems like for a while before a National Grid every power station had their own power values and that if two companies wanted to trade power they needed a set of Motor -Generators or Rotary transformers to convert to the others standard. 110 volt 25 cycle seemed to be the popular one when a national grid required a national standard until the early 1950s when 120vac 60 cycle became the standard.