I was doing a residenatial service change today on a house that was built in the 1920-1930 era. How were those guy's able to keep up on which wires were hots/neuts. through out the house. I also noticed that at times they were using neuts on a switch to make/break ckts. when did this practice stop?
Wireing Methods
- Thread starter torint
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Re: Wireing Methods
I believe you answered your own question with your question.
Maybe they didn't or we sure can't tell the difference now.
I always assumed when they where originally wired when the wires where clean they had a distinctive color of gray and black or white and black. But you no what assume means.
Ronald
I believe you answered your own question with your question.
Maybe they didn't or we sure can't tell the difference now.
I always assumed when they where originally wired when the wires where clean they had a distinctive color of gray and black or white and black. But you no what assume means.
Ronald
jtb
Senior Member
- Location
- Pennsylvania
Re: Wireing Methods
I agree. I think at the time of install, there were colors on the Knob and tube. Those colors probably faded, or got covered with coal dust from the heating of old.
I agree. I think at the time of install, there were colors on the Knob and tube. Those colors probably faded, or got covered with coal dust from the heating of old.
alan mcneil
Member
- Location
- Massachusetts
Re: Wireing Methods
Many moons ago I changed a sevice in a house that had some knob and tube.
The job went well, but as we were leaving the owner of the house informed us that the 3 way switches that controlled the hall lights did not work properly.
What a horror show that turned into, back then they used a weird method to control 3 ways without using 3 wire cable, it was a mixture of knob & tube and the old bx 2 wire cable.
As it turned out - when we changed the service and connected the branch circuits we could not tell what was the neutral, this affected the 3 way switches when we connected the wiring in the basement.
Many moons ago I changed a sevice in a house that had some knob and tube.
The job went well, but as we were leaving the owner of the house informed us that the 3 way switches that controlled the hall lights did not work properly.
What a horror show that turned into, back then they used a weird method to control 3 ways without using 3 wire cable, it was a mixture of knob & tube and the old bx 2 wire cable.
As it turned out - when we changed the service and connected the branch circuits we could not tell what was the neutral, this affected the 3 way switches when we connected the wiring in the basement.
cm
Member
- Location
- Pennsylvania
Re: Wireing Methods
The old timers used a coast /carter /chicago 3 way [the name depends where you live], they fed the travlers with the hot and neutral,this was popular because they could feed a second floor and make a 3way work off two wires, the switch floped from the hot or neutral and used 1 wire up to the lite from each 3way . YOU must be very carefull when you split up circuits if you feed each switch with an oppsite phase you will put 240 vac across the hall lite boof, also lots of k&t systems were 120 volt if you try to use multiwire home runs funny things happen.
The old timers used a coast /carter /chicago 3 way [the name depends where you live], they fed the travlers with the hot and neutral,this was popular because they could feed a second floor and make a 3way work off two wires, the switch floped from the hot or neutral and used 1 wire up to the lite from each 3way . YOU must be very carefull when you split up circuits if you feed each switch with an oppsite phase you will put 240 vac across the hall lite boof, also lots of k&t systems were 120 volt if you try to use multiwire home runs funny things happen.
scotty
Member
- Location
- Connecticut
Re: Wireing Methods
yes that old knob and tube wiring can really confuse most people,I know the three way's, and the taps that sometimes apper in walls can set me back for awhile. So when did they stop this wiring method. I don't know, but what about fused neturals?? I can show you two houses with these working systems
yes that old knob and tube wiring can really confuse most people,I know the three way's, and the taps that sometimes apper in walls can set me back for awhile. So when did they stop this wiring method. I don't know, but what about fused
neturals?? I can show you two houses with these working systems
al hildenbrand
Senior Member
- Location
- Minnesota
- Occupation
- Electrical Contractor, Electrical Consultant, Electrical Engineer
Re: Wireing Methods
Scotty,
The 1975 NEC restricted K&T to
Al
Scotty,
The 1975 NEC restricted K&T to
Up until then, it was still an unrestricted method.
Al
mvannevel
Senior Member
- Location
- Hesperia, Michigan
Re: Wireing Methods
Years ago, we had an "old timer" working for us who started out in the trade running knob & tube. According to him, the true craftsmen in the trade took pride in a good, neat installation. And, believe it or not, I've seen lots of nice k&t installations. Depending on conditions in the house, on some of them it was still possible to tell the white wires from the black. He also swore up and down that some contractors would hire a couple of "hay shakers", start one at one end of the house with a roll of black wire, one at the other end with a roll of white wire, and wherever they crossed paths would be a light, switch or receptacle. I've also seen more than my share that looked like that was exactly what happened. Times and methods have changed, but you can still spot a true craftsman's work.
Years ago, we had an "old timer" working for us who started out in the trade running knob & tube. According to him, the true craftsmen in the trade took pride in a good, neat installation. And, believe it or not, I've seen lots of nice k&t installations. Depending on conditions in the house, on some of them it was still possible to tell the white wires from the black. He also swore up and down that some contractors would hire a couple of "hay shakers", start one at one end of the house with a roll of black wire, one at the other end with a roll of white wire, and wherever they crossed paths would be a light, switch or receptacle. I've also seen more than my share that looked like that was exactly what happened. Times and methods have changed, but you can still spot a true craftsman's work.
cselectric
Senior Member
- Location
- Wisconsin
Re: Wireing Methods
CM. I have to say, you are the first person I've ever heard mention the old Chicago 3 way system. I thought I was the only guy ever to stumble across that little nightmare. As for watching yourself, your right about the 240 problem, but you also have to be careful just changing the lamps. The way the system is designed, you never know which part of the socket is hot, could be the bottom tab, could be the screw shell.
CM. I have to say, you are the first person I've ever heard mention the old Chicago 3 way system. I thought I was the only guy ever to stumble across that little nightmare. As for watching yourself, your right about the 240 problem, but you also have to be careful just changing the lamps. The way the system is designed, you never know which part of the socket is hot, could be the bottom tab, could be the screw shell.
mvannevel
Senior Member
- Location
- Hesperia, Michigan
Re: Wireing Methods
You're absolutely right about the old Chigago three-ways. You never know what you're grabbing ahold of at the fixture. The design is such that when the lamp is off, either both the screw shell and the bottom tab are connected to the neutral, or they are both connected to the hot. I used to run into them frequently, but nothing beats the first time you run across one. Best tool in the world on k&t jobs is a neon tester. Goes a long way towards keeping you from getting poked...
You're absolutely right about the old Chigago three-ways. You never know what you're grabbing ahold of at the fixture. The design is such that when the lamp is off, either both the screw shell and the bottom tab are connected to the neutral, or they are both connected to the hot. I used to run into them frequently, but nothing beats the first time you run across one. Best tool in the world on k&t jobs is a neon tester. Goes a long way towards keeping you from getting poked...
cm
Member
- Location
- Pennsylvania
Re: Wireing Methods
Cselectric,I grew up in an old mill town,every house in town had a gas lite system,then the k&t systems were added I have found cut slate open fuse wire panels lined with asbestos,gas lite dead ends with a celing lite hung off it with gas still in the pipe chicago three ways they callem carter 3 ways here,and everything guys comment about on this forum.The classic service call on a k&t system is we changed a hall lite switch and none of the lites work upstairs.If k&t was so bad the whole town would be burnt down amazingly it isnt.another classic call is we bought a dimmer at home depot hooked it up and it went boof and blew the fuse, The books and lessons at home depot and lowes dont cover thease things ha ha and I dont know about you but I dont appreciate how they make our trade sound so easy to do so they can sell materials to unqualifed people
[ February 26, 2003, 05:34 PM: Message edited by: cm ]
Cselectric,I grew up in an old mill town,every house in town had a gas lite system,then the k&t systems were added I have found cut slate open fuse wire panels lined with asbestos,gas lite dead ends with a celing lite hung off it with gas still in the pipe chicago three ways they callem carter 3 ways here,and everything guys comment about on this forum.The classic service call on a k&t system is we changed a hall lite switch and none of the lites work upstairs.If k&t was so bad the whole town would be burnt down amazingly it isnt.another classic call is we bought a dimmer at home depot hooked it up and it went boof and blew the fuse, The books and lessons at home depot and lowes dont cover thease things ha ha
and I dont know about you but I dont appreciate how they make our trade sound so easy to do so they can sell materials to unqualifed people[ February 26, 2003, 05:34 PM: Message edited by: cm ]
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