Home>Discussions>ELECTRICAL & LIGHTING>Help with my 100 yr. old home's wiring
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shanefish
Help with my 100 yr. old home's wiring

Firstly, I am a novice and would have hired someone if I could afford it, but I cannot and have opened up my kitchen walls and am in need of some assistance if anyone can help.

I have a kitchen light with 2 K.T. wires coming in and out, one hot and one not. The light is controlled by a switch at LOCATION 1 via a wire named LINE 1 with a black and white wire attached to a 3-way switch (the white one to the common and black one to one of the others.) There is nothing connected to the other screw. This LINE 1 was added prpbably in the 50's and travels under my floor into a box on the opposite wall in the kitchen. The white from LINE 1 connects to another wire and travels up the wall at LOCATION 2. However, at LOCATION 2, the black wire from LINE 1 meets up and is pig-tailed to a wire (LINE 2) and also pigtailed to a switch at LOCATION 2. It appears LINE 2 is split going up and down in the wall and I believe the upper is the incomeing hot wire. The switch at LOCATION 2 does not appear to control anything and is only a 2-way switch.

I am soooo confused...help!
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MICHIGAN MEDICAL MARIJUANA DISPENSARY

shanefish
Re: Help with my 100 yr. old home's wiring

May I add that at LOCATION 2 there is a mystery wire that has no juice, travels both up and down in the wall and has a pig-tail at LOCATION 2's box but that end is just capped off and goes no where. Could this have been the common in an old 3-way box. I believe the electrical was put in the 1920's or 30's, then upgraded in the 50's and 70's. I have wires literally all over the place. I cannot reach the knob and tube wires to pull new wire but can probably run all new if I can figure out where the hot wire comes in I guess. My wife is about to kill me and I need some advice if you can help.
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Marijuana seeds

shanefish
Re: Help with my 100 yr. old home's wiring

I have a diagram and photos if that helps. I find it odd that the power comes into one switch and is pig-tailed to another switch and it is that switch which controls the light. I am baffled even after staring at it for hours last night.
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S-class

shanefish
Re: Help with my 100 yr. old home's wiring

I am posting some photos and a diagram to help. I will also post another write-up of the issues below. Thanks in advance!

Location 1 is where the current switch is for the kitchen light. I wanted to install a 3-way switch at another location, so I opened up the outlet to investigate. I am doing a semi-remodel of my kitchen. Nothing major, just new outlets and surfaces mostly. Location 2 is where i found the incoming hot wire for the overhead light. It is pig-tailed to a 2-way switch at Location 2 (which when switched does nothing) as well as pig-tailed to the black wire from the other switch. Location 1 has a 3-way switch with only 2 wires hooked up, a white to the common and black to one of the other screws. At location 2, wires #1 and 2 are to an outlet I am re-routing to service my new microwave. Wires 3 and 4 were attached to the useless switch. Wire 3 is the black from location 1 and 4 is neutral and goes up inside the ceiling. Wire #5 is pigtailed to the white from Location 1 and travels up inside the ceiling. Wire #7 goes up and down the ceiling and is pigtailed, but taped capped off at Location 2. Wire #3A is hot and brings power from up inside the ceiling and is pigtailed to wire #3 and to the useless switch at Location 2. 3A also travels up and down the wall, but I traced the lower wire and it appears to not be hot in the basement.
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How To Roll A Joint

Blue RidgeParkway
Re: Help with my 100 yr. old home's wiring

K & T should never be "capped off" anywhere not contained in a proper box. K&T splices should always be soldered. You don't have electrical boxes at any of these locations.

Your local building office can advise you as to what codes are in effect in your area as well as a list of local rules/ammendments.

I suggest you acquire them then do some research at your local library.

To work with K&T you must know how to properly do a splice. Flying splices are generally no longer permitted even when repairing.

Without a proper ground available it will be difficult to trace your wiring.

There is no way to know by just looking at photos if your original switches were wired correctly they could have been switching the "neutral". Sadly, it is not uncommon to find wiring errors in vintage homes with generations of modifications to the electrical system (yes even replacing or adding a switch being a change that could repeat or introduce a wiring error, and see some old cable in one of the switch photos so there have been modifications over time - can't rely on any of those having been correct or even safe at the time, let alone correct by today's standards). One of the big concerns with K & T is that if it is older, even moving a portion of it can cause the insulation to break/flake off.

P.S. that skinny little wire is very concerning (marked "6) as pictured - location, etc.

shanefish
Re: Help with my 100 yr. old home's wiring

#6 wire is actually conected to the common on the 3-way switch at the other location. I have them seperated from the other wires for the photo. It was pig-tailed to another neutral wire which runs up the wall. The knob and tube is in the ceiling and I was hoping to avoid touching these wires/ or just rewire if I can figure where to terminate the old wiring. The only wire that was "capped off" was not hot in any direction.
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Halfbaked

shanefish
Re: Help with my 100 yr. old home's wiring

Also, #3 and #6 are in the same casing and appear to have been added in the 50's.
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Mercury M-Series Specifications

JLMCDANIEL
Re: Help with my 100 yr. old home's wiring

See if this helps Shanefish

The white wires on the switches should be taped with black because they are not common.
The first drawing shows how K&T was originally wired in old houses with hot going up one side of the house and common going up the other. Connections were spliced in to the main runs to each light fixture with a pull chin. When a switch was added the hot was disconnected from the fixture and nutted to a wire going to the switch and the return from the switch was then connected to the fixture.(second drawing) A 3-way is basically the same except the hot disconnected from the light goes to one switch, 2 wires were run from that switch to the other switch and the return to the light comes from the second switch.

Although there were variations this is the basic wiring method.
Jack

Fencepost
Re: Help with my 100 yr. old home's wiring
Blue RidgeParkway wrote:

K & T should never be "capped off" anywhere not contained in a proper box. K&T splices should always be soldered. You don't have electrical boxes at any of these locations.

Your local building office can advise you as to what codes are in effect in your area as well as a list of local rules/ammendments.

I suggest you acquire them then do some research at your local library.

To work with K&T you must know how to properly do a splice. Flying splices are generally no longer permitted even when repairing.

Without a proper ground available it will be difficult to trace your wiring.

There is no way to know by just looking at photos if your original switches were wired correctly they could have been switching the "neutral". Sadly, it is not uncommon to find wiring errors in vintage homes with generations of modifications to the electrical system (yes even replacing or adding a switch being a change that could repeat or introduce a wiring error, and see some old cable in one of the switch photos so there have been modifications over time - can't rely on any of those having been correct or even safe at the time, let alone correct by today's standards). One of the big concerns with K & T is that if it is older, even moving a portion of it can cause the insulation to break/flake off.

P.S. that skinny little wire is very concerning (marked "6) as pictured - location, etc.

Just to clarify, you don't have to solder K&T *IF* the joint is in an accessible junction box with a proper c0ver.

Heat-shrink tubing (properly rated for the voltage, of course) is an excellent method of protecting wires with brittle insulation. You can try taping, but in my experience tape doesn't stick well to the old rubber-and-cloth covered wires.

Blue RidgeParkway
Re: Help with my 100 yr. old home's wiring
Fencepost wrote:

Just to clarify, you don't have to solder K&T *IF* the joint is in an accessible junction box with a proper c0ver.

Heat-shrink tubing (properly rated for the voltage, of course) is an excellent method of protecting wires with brittle insulation. You can try taping, but in my experience tape doesn't stick well to the old rubber-and-cloth covered wires.

Just to clarify, if the NEC is the adopted code, and no language has been ammeded or altered, you MUST solder K & T UNLESS your LOCAL AUTHORITY HAVING JURISDICTION has APPROVED another splicing device or method for use with Knob & Tube whether the splice is in a box or not. The approval lays with the AUTHORITY HAVING JURISDICTION, not a testing lab, not a manufacturer.

JLMCDANIEL
Re: Help with my 100 yr. old home's wiring
Fencepost wrote:

Just to clarify, you don't have to solder K&T *IF* the joint is in an accessible junction box with a proper c0ver.

Heat-shrink tubing (properly rated for the voltage, of course) is an excellent method of protecting wires with brittle insulation. You can try taping, but in my experience tape doesn't stick well to the old rubber-and-cloth covered wires.

You are correct, NEC 394.56 states "splices shall be soldered unless approved splicing devices are used" and wire nuts are approved splicing devices if used in a box w/cover.
Jack

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