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Simple house wiring issue

Muse

Lifer
Jul 11, 2001
30,186
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My garage is distanced from the house by about 15 feet. It's wired for two AC current outlets and an overhead light in the middle. The boxes don't have a ground (i.e. they won't accommodate a 3 pronged plug). There are two wires leading from the garage, heavy copper cored, and coiled, disconnected from the two wires that lead out from under the roof eve of my kitchen. I tested the coiled wires outside the garage today and there's continuity. If AC is connected to those wires, the plug boxes will work and I assume the overhead light in the middle will function (there's a switch on one of the AC boxes, that I am certain controls that light).

The wiring in my 111 year old house is, well, old! I think it's called "standard knob and tube wiring." The AC plugs in the house are all (I think) 3 pronged, but AFAIK, there's no ground on any of them except for a few that I hand wired to some reasonable ground (e.g. a cold water pipe outside).

I'm contemplating repiping the house (copper, I guess, but I saw a Youtube video recently saying "pex" makes a lot of sense, won't corrode). Anyway, rewiring isn't something I figure to do right away.

I'd like to hook up the garage and figure it's simple as turning off the electricity and hooking up the two wires coming from the garage and the ones coming from under the roof edge outside my kitchen. I don't remember how or why those wires were disconnected, I think the garage was hooked up ~20 years ago when I bought the house.

Well, my question is this: The AC outlets in the garage accommodate modern non-grounded plugs, i.e. one prong is wider than the other, so orientation presumably matters! So, how do I determine which wire goes to which wire? Also, please explain if possible why and how it matters. Thanks!
 

Paperdoc

Golden Member
Aug 17, 2006
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Danger, Will Robinson!

What you wish could easily create a dangerous situation, given that the electrical system in your house is quite antequated. Moreover, you do not understand even what the issues are that need to be addressed. My suspicion is that someone disconnected the garage feed precisely to prevent some electrical hazard out there. I won't help, in the interest of protecting OP from unknown problems AND legal issues of liability and voided insurance.I'd rather Muse keeps coming around here.
 

pcgeek11

Lifer
Jun 12, 2005
18,127
2,032
126
That is a bit more than a "Simple House Wiring Issue".

I agree with Paperdoc. You should upgrade your wiring in your house and the garage.It is probably a requirement when you do electrical work that you upgrade to current requirements / standards.

Knob and tube wiring. Jesus, I haven't seen that in many years.

 
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Greenman

Lifer
Oct 15, 1999
17,308
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That is a bit more than a "Simple House Wiring Issue".

I agree with Paperdoc. You should upgrade your wiring in your house and the garage.It is probably a requirement when you do electrical work that you upgrade to current requirements / standards.

Knob and tube wiring. Jesus, I haven't seen that in many years.

It's not required that it be upgraded unless it's exposed while remodeling. K&T isn't fundamentally unsafe, it just doesn't have a ground.
I'd be more than a little concerned about firing up a system that was disconnected 20 years ago. It's safe to assume that there was a reason for it being disconnected.

As far as rewiring the whole house goes, I wouldn't do it. Muse has made a few posts about his home. As I recall, it no longer has heat, the plumbing is past it's service life, his kitchen cabinets and counter tops are original and not in good shape, there is failing brick work on the exterior, and it's a pretty fair bet it isn't insulated. It's also a fair bet that it has more than a few coats of lead based paint on it, and most likely some asbestos laying around. In other words, it's a 111 year old house, and it's getting very near complete update time. Doing that piecemeal will end up costing a great deal more, and the end result won't be as good.
 

Muse

Lifer
Jul 11, 2001
30,186
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It's not required that it be upgraded unless it's exposed while remodeling. K&T isn't fundamentally unsafe, it just doesn't have a ground.
I'd be more than a little concerned about firing up a system that was disconnected 20 years ago. It's safe to assume that there was a reason for it being disconnected.

As far as rewiring the whole house goes, I wouldn't do it. Muse has made a few posts about his home. As I recall, it no longer has heat, the plumbing is past it's service life, his kitchen cabinets and counter tops are original and not in good shape, there is failing brick work on the exterior, and it's a pretty fair bet it isn't insulated. It's also a fair bet that it has more than a few coats of lead based paint on it, and most likely some asbestos laying around. In other words, it's a 111 year old house, and it's getting very near complete update time. Doing that piecemeal will end up costing a great deal more, and the end result won't be as good.
Complete update is what? Tear down and rebuild? When I bought the house 21 years ago I had it inspected by GC. What I didn't expect was that he'd propose to renovate the house, but that's exactly what he did. For $150k he would have redone the foundation, and I'm guessing now (because I haven't seen his document in a while, but I'm sure it's in my filing cabinet) rewire, repipe, paint, remodel kitchen and baths. He told me he'd done 9 other houses similar to mine. He's long since retired. At the time I didn't have $150k. In fact when I closed I had 1k left, which I immediately forked over for a new fridge (well, virtually new, IIRC it was an open box type affair from Airport Appliance), which I still have. Being broke didn't worry me, I had a decent full time job at the time.

I'm pretty confident there was no reason for disconnecting the garage. It just happened, probably a branch from the plum tree between the house and garage falling on the wires and breaking them, that simple. I have personally trimmed both large plum trees with an electric pole saw all this time.

Actually, electricity in the garage isn't a big deal. It's not something I miss. There's the lift up door on the end and two sky lights. It's plenty bright during the day and I generally have no need to go in there at night and if I did, I have flashlights galore. Electricity in there isn't something I crave, when I use electricity in back of the house I just use the outlet under my tankless water heater and a long extension cord. I figured to do it just because it would be really easy and seems silly to have outlets and lights that don't function, for the most part. I had the garage reroofed and totally replaced one wall almost 4 years ago and I have some extra stuff to do, figured the electricity would be trivial to restore.
 
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pcgeek11

Lifer
Jun 12, 2005
18,127
2,032
126
It's not required that it be upgraded unless it's exposed while remodeling. K&T isn't fundamentally unsafe, it just doesn't have a ground.
I'd be more than a little concerned about firing up a system that was disconnected 20 years ago. It's safe to assume that there was a reason for it being disconnected.

As far as rewiring the whole house goes, I wouldn't do it. Muse has made a few posts about his home. As I recall, it no longer has heat, the plumbing is past it's service life, his kitchen cabinets and counter tops are original and not in good shape, there is failing brick work on the exterior, and it's a pretty fair bet it isn't insulated. It's also a fair bet that it has more than a few coats of lead based paint on it, and most likely some asbestos laying around. In other words, it's a 111 year old house, and it's getting very near complete update time. Doing that piecemeal will end up costing a great deal more, and the end result won't be as good.
Well I agree it isn't fundamentally unsafe. He has a 111 year old house and much of that wiring probably has failing insulation etc. I have seen much younger houses with K&T Wiring and exposed copper everywhere.

I have also read about his many issues with this house in here. I think it is well past complete update time...
 

Red Squirrel

No Lifer
May 24, 2003
59,685
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www.uovalor.com
An easy fix is to replace ungrounded outlets with GFCI. If they are part of a string of outlets you only need the first one to be GFCI. If any current goes to ground (any ground) instead of returning to neutral it will trip the GFCI. This will provide some basic safety.

Given the wiring is that old I would be inclined to look at upgrading it, at least doing the areas that are easier to fish. But yeah if the house is that old it's probably not that easy to fish anything. Walls are probably lathe and plaster too so any holes that would need to be done would create a pretty big mess and be harder to repair. Another option, although maybe not practical or the type of look you want but you could do everything surface mount with EMT conduit and metal boxes and abandon everything in the walls. Though if the basement is finished this is still going to be a hard job to do.
 

Steltek

Platinum Member
Mar 29, 2001
2,816
594
136
An easy fix is to replace ungrounded outlets with GFCI. If they are part of a string of outlets you only need the first one to be GFCI. If any current goes to ground (any ground) instead of returning to neutral it will trip the GFCI. This will provide some basic safety.

Given the wiring is that old I would be inclined to look at upgrading it, at least doing the areas that are easier to fish. But yeah if the house is that old it's probably not that easy to fish anything. Walls are probably lathe and plaster too so any holes that would need to be done would create a pretty big mess and be harder to repair. Another option, although maybe not practical or the type of look you want but you could do everything surface mount with EMT conduit and metal boxes and abandon everything in the walls. Though if the basement is finished this is still going to be a hard job to do.
I wouldn't touch existing lath and plaster wallboard in any house that old without first having it evaluated for asbestos, which was commonly used in plaster back then.

While it is generally considered safe as long as it is undisturbed, cutting holes in asbestos-containing plaster or wallboard could create a very bad situation.
 
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Red Squirrel

No Lifer
May 24, 2003
59,685
8,599
126
www.uovalor.com
I wouldn't touch existing lath and plaster wallboard in any house that old without first having it evaluated for asbestos, which was commonly used in plaster back then.

While it is generally considered safe as long as it is undisturbed, cutting holes in asbestos-containing plaster or wallboard could create a very bad situation.
Yeah that's a good point there could very well be asbestos as part of the plaster.
 
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Greenman

Lifer
Oct 15, 1999
17,308
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Complete update is what? Tear down and rebuild? When I bought the house 21 years ago I had it inspected by GC. What I didn't expect was that he'd propose to renovate the house, but that's exactly what he did. For $150k he would have redone the foundation, and I'm guessing now (because I haven't seen his document in a while, but I'm sure it's in my filing cabinet) rewire, repipe, paint, remodel kitchen and baths. He told me he'd done 9 other houses similar to mine. He's long since retired. At the time I didn't have $150k. In fact when I closed I had 1k left, which I immediately forked over for a new fridge (well, virtually new, IIRC it was an open box type affair from Airport Appliance), which I still have. Being broke didn't worry me, I had a decent full time job at the time.

I'm pretty confident there was no reason for disconnecting the garage. It just happened, probably a branch from the plum tree between the house and garage falling on the wires and breaking them, that simple. I have personally trimmed both large plum trees with an electric pole saw all this time.

Actually, electricity in the garage isn't a big deal. It's not something I miss. There's the lift up door on the end and two sky lights. It's plenty bright during the day and I generally have no need to go in there at night and if I did, I have flashlights galore. Electricity in there isn't something I crave, when I use electricity in back of the house I just use the outlet under my tankless water heater and a long extension cord. I figured to do it just because it would be really easy and seems silly to have outlets and lights that don't function, for the most part. I had the garage reroofed and totally replaced one wall almost 4 years ago and I have some extra stuff to do, figured the electricity would be trivial to restore.
A complete update generally means new plumbing, electric, HVAC, insulation, windows, kitchen and baths. I didn't know that a contractor thought you needed a new foundation 20 years ago. That changes the equation quite a bit. Though my guess is he was going for an upsell.
 
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deadlyapp

Diamond Member
Apr 25, 2004
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I'm surprised that others haven't said anything, but your comment about the wire being basically draped through open air and can be knocked down by a tree is the most worrisome to me. Standard Romex (which probably isn't even what you have) is not designed for being exposed to the elements and probably someone recognized that and cut what you had previously. In order to do this safely, you at the very least would need to run conduit or liquidtight flex, and the best way would be to trench it. If you run conduit/liquidtight, you can't use romex, you'd have to use individual strand.

Everything here screams danger though, and you'll soon enough end up with no garage after it burns down based on the cavalier nature you're looking at this work.
 
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Paperdoc

Golden Member
Aug 17, 2006
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As background, we bought this old house in 1971 for a low price - it was all we could scrounge up while I was a grad student. It is a 2-story wood frame house on a solid poured concrete basement, probably built in the 1910's or 20's - no record to tell us. It did have knob-and-tube wiring with a couple of added circuits using Loomex, 60A service. My first major update was to learn how and do a complete electrical upgrade to a new 100 A service (fuse panel rather than breakers, for lower cost), fully approved by inspector of course. House has plaster walls over lath. There was much less awareness of asbestos then, so I did not worry about that. Basically I ran all lower-level cables around the exposed beams in the basement and up through floors to individual outlet and switch boxes. There were no fire-stop blocks horizontally inside the walls, so fishing cables was OK. For centrally-located ceiling light fixtures in each room I had to cut a few holes, but no major wall rip-outs. For the upper floor, I created a single opening in one bay in an interior wall of the ground and upper floors and used that to run about 10 cables from basement to attic, then ran around there and down through walls for outlet boxes. Years later when we renovated the kitchen, my old knowledge made it easy to install the new wiring needed for that project.

So I am very familiar with what many posts above address - knob and tune, plaster walls, fishing cable, etc. We recently had to have an older house that belonged to my deceased mother-on-law updated from old 60 A (WWII era) service to 100 A without replacing all the in-wall wiring. I did not tackle that job, but I knew enough to be able to converse competently with the contractor and understand what they did. They added only a couple of requested circuits and replaced a very poor buried electrical feed to the garage with a proper Teck cable and panel. That job was based on advice from a real estate appraiser - these days most insurance companies will not offer to insure a house with wiring that old, so it would be hard for the estate to sell.
 

Muse

Lifer
Jul 11, 2001
30,186
3,573
126
An easy fix is to replace ungrounded outlets with GFCI. If they are part of a string of outlets you only need the first one to be GFCI. If any current goes to ground (any ground) instead of returning to neutral it will trip the GFCI. This will provide some basic safety.

Given the wiring is that old I would be inclined to look at upgrading it, at least doing the areas that are easier to fish. But yeah if the house is that old it's probably not that easy to fish anything. Walls are probably lathe and plaster too so any holes that would need to be done would create a pretty big mess and be harder to repair. Another option, although maybe not practical or the type of look you want but you could do everything surface mount with EMT conduit and metal boxes and abandon everything in the walls. Though if the basement is finished this is still going to be a hard job to do.
Thanks! There's no basement, just a crawl space (where I've been quite a few times doing this and that). The K&T can be seen in the attic, where I've also been a bunch of times. I can at least stand up in the attic, in some places, but need to dodge 2x4's and step on joists! One of my roommates (before I bought the house and kicked those slackers out) was up there and stepped on some wiring, screwing it up. I had to repair that.

I'm pretty dang handy, but I certainly have my limitations. I did a bit of googling after starting this thread and getting the blowback, found a video where a guy shows how you determine the hot in K&T, it's real easy. I still don't understand why they have a hot for it. I mean isn't A/C just current jumping back and forth in a wire when you close the circuit? I should understand this stuff, I was a physics major for a while, but somehow the nuances of EE have largely eluded me to a large degree.
 

Muse

Lifer
Jul 11, 2001
30,186
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A complete update generally means new plumbing, electric, HVAC, insulation, windows, kitchen and baths. I didn't know that a contractor thought you needed a new foundation 20 years ago. That changes the equation quite a bit. Though my guess is he was going for an upsell.
The foundation is really the bitch on this house. I wish I'd had the dough to take him up on his bid to fix the house. It would have included doing the foundation. I've had some of the best GCs around (back in the early oughts) look over that aspect of things and was told that getting after this house, starting with the foundation issue, I'd be putting money in I'd never get out. So, I tabled that. I figure I should just move/sell! Easier said than done. It's sure a seller's market right now!
 

deadlyapp

Diamond Member
Apr 25, 2004
5,899
348
126
Thanks! There's no basement, just a crawl space (where I've been quite a few times doing this and that). The K&T can be seen in the attic, where I've also been a bunch of times. I can at least stand up in the attic, in some places, but need to dodge 2x4's and step on joists! One of my roommates (before I bought the house and kicked those slackers out) was up there and stepped on some wiring, screwing it up. I had to repair that.

I'm pretty dang handy, but I certainly have my limitations. I did a bit of googling after starting this thread and getting the blowback, found a video where a guy shows how you determine the hot in K&T, it's real easy. I still don't understand why they have a hot for it. I mean isn't A/C just current jumping back and forth in a wire when you close the circuit? I should understand this stuff, I was a physics major for a while, but somehow the nuances of EE have largely eluded me to a large degree.
So - from the pole, you have three wires. Two of them are hot, alternating current, and one is neutral. The neutral is just tied into your ground. When you wire a standard 120V outlet, you only use one of the hot wires, and then one neutral. Usually the neutral bar is just tied to the ground bar within a fuse panel. I'm not as familiar with K&T but I assume that it just bypasses a ground and goes straight to the exterior ground. For 240V you use two hot wires and the neutral (and sometimes also a ground).
 

Steltek

Platinum Member
Mar 29, 2001
2,816
594
136
Thanks! There's no basement, just a crawl space (where I've been quite a few times doing this and that). The K&T can be seen in the attic, where I've also been a bunch of times. I can at least stand up in the attic, in some places, but need to dodge 2x4's and step on joists! One of my roommates (before I bought the house and kicked those slackers out) was up there and stepped on some wiring, screwing it up. I had to repair that.

I'm pretty dang handy, but I certainly have my limitations. I did a bit of googling after starting this thread and getting the blowback, found a video where a guy shows how you determine the hot in K&T, it's real easy. I still don't understand why they have a hot for it. I mean isn't A/C just current jumping back and forth in a wire when you close the circuit? I should understand this stuff, I was a physics major for a while, but somehow the nuances of EE have largely eluded me to a large degree.
You are confusing the definition of alternating current with electrical wiring terminology.

In standard wiring terms, the hot wire is so designated because it is the wire that carries electrical current from the circuit breaker in the panel to the load point in the circuit.

The neutral wire is so designated because it returns the remaining electrical current from the load point in the circuit back to the breaker panel. You need such a circular path with differences in electrical potential to create an electrical circuit.

The different terms are used for standardization purposes, so that the polarity of the circuit is always kept in the same direction and not reversed. Electricity is intended only to run in one direction. Having a reversed polarity circuit (where the hot and neutral wires are reversed) will still allow the circuit to work, as the electrical potential is still there, but will create a dangerous shock hazzard (i.e. in that electricity flows backward through the circuit until it hits a turned off switch as opposed to hitting a turned off switch and not being able to enter the remaining portion of the circuit. This leads to a situation with reversed polarity circuits where appliances you think are turned off can actually still be energized even when the switch is turned off. Because of this situation, in addition to the shock hazzard, it can also easily damage electronics because you have current flowing in directions through the electronics it was never intended to be in the design of the appliance).

You can be shocked in a live circuit by either the hot or neutral wire if you short it and provide an alternate path to ground for current in the live circuit to flow through.
 
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NutBucket

Lifer
Aug 30, 2000
26,430
268
126
I'm surprised that others haven't said anything, but your comment about the wire being basically draped through open air and can be knocked down by a tree is the most worrisome to me. Standard Romex (which probably isn't even what you have) is not designed for being exposed to the elements and probably someone recognized that and cut what you had previously. In order to do this safely, you at the very least would need to run conduit or liquidtight flex, and the best way would be to trench it. If you run conduit/liquidtight, you can't use romex, you'd have to use individual strand.

Everything here screams danger though, and you'll soon enough end up with no garage after it burns down based on the cavalier nature you're looking at this work.
Agreed on this. My parent's house was wired like this for decades. I rewired the garage when I was in my early 20's after they had replaced their (4 circuit!) panel. I did 6/3 direct burial Romex and a 60amp sub. Luckily there was a line of bricks through the patio so it was fairly easy to run the cable.

To this point, a pair of flying wires was very common from what I see around the neighborhood. Garages were likely built without power and homeowners added it later.
 

Greenman

Lifer
Oct 15, 1999
17,308
2,542
126
The foundation is really the bitch on this house. I wish I'd had the dough to take him up on his bid to fix the house. It would have included doing the foundation. I've had some of the best GCs around (back in the early oughts) look over that aspect of things and was told that getting after this house, starting with the foundation issue, I'd be putting money in I'd never get out. So, I tabled that. I figure I should just move/sell! Easier said than done. It's sure a seller's market right now!
Prices are going up fast enough that you should reevaluate that plan before making a decision. It's possible there is money to be made by doing a total update before selling. You're in the right location. The trick is figuring out the homes real value as it sits, compared to it's value if it was in perfect condition.
This is where flippers make their money, and sometimes it's serious money. I bid a project out that way for a crazy lady, she decided there was no profit in fixing up a house that had been vacant for 12 years. She sold it to a contractor, he did a complete overhaul, and netted a $600k profit for 5 months work.
 
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Paperdoc

Golden Member
Aug 17, 2006
1,981
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Muse, maybe this will help a little. Throughout most of North America (and some other parts of the world) the common way to supply power to a house is a system of two "Hot" lines from opposite ends of a transformer secondary winding, and a Neutral line from a centre tap. The transformer design is such that there is 240 VAC across the entire secondary, so 120 VAC between the centre tap (Neutral) and each end. Of course, all that is just "floating" Potential with voltages expressed with respect the transformer terminals only. So as a first point of safety, the Neutral line is connected to true earth Ground at the transformer. Thus we call this a "Grounded Neutral" feed system, and all voltages may now be referenced to true earth Ground. Neutral is 0 VAC, and each Hot is 120 VAC with respect to ground, with 240 VAC between the two Hots. For clear labelling at your breaker or fuse panel, the two Hot lines are called L1 and L2.

Since L1 and L2 are from opposite ends of the transformer secondary, the sine wave voltages between each of those and the Neutral (centre tap) are exactly 180 degrees out of phase. In your house with different loads connected from L1 to Neutral and L2 to neutral, the net CURRENT flowing back to the transformer along the Neutral cable is the imbalance or DIFFERENCE between the currents flowing in from the L1 and L2 lines.

At the breaker or fuse panel in your house, a bare copper line establishes a good connection to a true earth Ground - typically via the metal water supply line entering your house, but could be other means. In your panel (in modern house wiring systems, but maybe not in an older system like yours) that Ground line is connected to a Ground Bus used for all of the bare copper Ground wires ("bonding wires") in all the branch circuit cables through the house, and these are connected at every outlet to the round third plug blade hole. In addition, at every electrical device box the metal mounting box itself is connected to that Bonding Wire, and the exterior chassis of any connected load device (like a light fixture) is connected thusly also. That way any exterior part you might be able to touch is Grounded.

Also in your panel, the incoming Neutral line is connected again to the panel itself and to that Ground Bus and Ground line. Thus the Neutral is Grounded at both ends. The intent, however, is that the GROUND is to be used to carry away to true earth Ground only currents from abnormal situations, and normally should carry NO current. Thus it is always at truly zero Volts. The Neutral line, however, DOES carry the net returning current from all user devices. Because it IS carrying a current and has small but non-zero resistance, it DOES have a net voltage above zero whenever it is carrying currents. So, although the Neutral line is Grounded at two points, it can NOT be regarded as safe and harmless, whereas the bare Ground (Bonding Line) always should be at true Ground zero Volts.

In up-to-date house wiring, there are several rules about how these lines are used. A fuse or breaker in the panel is always where a branch circuit begins, and it feeds the Hot line of that circuit, colour coded Black for most. The Neutral line (colour code White) is connected directly to the panel Neutral bus - no fuse or switch or breaker in it to interfere with current return. The Bonding Line (bare copper) is connected to the panel Ground Bus. At an outlet with three blade holes, each hole now is different. Assume the outlet is arranged so that, when you look at it in the wall, the round hole is at the bottom. The two slots for the flat plug blades are above in an inverted triangle arrangement. The slot to the LEFT of centre is taller to accept a wider blade. That is the Neutral slot. The right-hand slot is not as tall and is the Hot slot. Even many 2-blade plugs are made with different blade widths so that you can only plug it into the outlet one way. Note that the WIDE slot (Neutral) can NOT fit into the NARROW Hot slot. Plugs with identical width prongs are allowed when the device it connects has no direct connection from either line to its exterior - for example, a small power supply unit that uses a transformer as the power input point. In the final power-consuming device, anything used to control the power - switch, fuse, etc. - is installed in the HOT line entering the device so power CAN be turned OFF completely. In a lamp, the Hot line though the switch must be connected to the small centre contact in the lamp base, leaving the socket shell (and hence the potentially exposed part of the lamp screw base) connected to Neutral that should be at very low voltage even when the lamp is operating.

There are several issues in older electrical systems that do not incorporate all these features and rules. In the old Knob-and-Tube wiring system, only the Hot and Neutral lines were installed for every branch circuit - there are no Bonding Lines. In fact, in many of those systems there may NOT be any connection of the fuse panel itself or of the entering Neutral Line to true Ground. So although the Neutral line feeding into your house IS connected to Ground at the transformer, it may not be at the second point in your panel. Now here's a big one. When that wiring system was installed, no attention was paid to the difference between Hot and Neutral. All that mattered was that there was a voltage difference that could be used for power. So ALL the branch wires are Black. At any wall outlet the fixture contained TWO slots of identical size. When wires were connected to that fixture, no attention was paid to which slot got which line. So you can NOT use the modern "rule" that the left slot is Neutral. Moreover, all the plugs used at that time had identical narrow widths, so you could plug any device in with the plug "up" or "down" (effectively reversing which wire into the device carried the Hot feed) and nobody thought that mattered. Even if you made the effort to go through your entire house and re-arranged the feed wires at each outlet to impose a rule that the LEFT slot is always Neutral, you'd still have outlets with two smaller slots that can only accept those plugs that can be plugged in either way! If, at the same time, you changed all the outlet fixtures to the new 3-prong type that forces you to plug in only one way, there still is NO true Ground connected anywhere! And of course, the dangerous tale happens when someone replaces on old 2-slot outlet fixture with a new 3-prong fixture, cannot connect any Ground, and does NOT try to figure out which feed line should go to which slot!

The use of GFCI devices (outlet fixtures) to "update" an older system like that lacking any Ground wires is a crutch - a pretty good one, but not the same. In a modern system, if there is any malfunction in a circuit or in a connected user device that allows current to "escape" its intended path and reach the accessible exterior, that exterior is connected to the Ground line. Thus any small current is carried away safely without allowing the Voltage on the exterior to become dangerous. THAT is why the Ground line must NOT ever be used to carry any other currents. If a large current flows because of the faulty unit, that will trip off the breaker or fuse supplying the Hot line of that circuit, removing all power. A Ground Fault Circuit Interrupter (GFCI) works differently and does not need a Ground for this purpose. It measures the current entering the GFCI unit from the Hot line and the current leaving on the Neutral Line. They should always match exactly. If any imbalance beyond a limit is detected, it shuts off the Hot line feed. This does NOT trip the breaker or fuse at the panel, but it removes all power from the attached device. Now, the original GFCI design was intended for use where electrical devices were used in somewhat hazardous locations (e.g., around a wet counter in a kitchen, or for outside yard tools). In those areas it is possible for small leakage currents to escape the device or tool and get to a person, even though those currents would not be sufficient to trip a fuse. The imbalance limit is set to less than the current through a human chest that might disrupt the heart and cause fibrillation and death. Using a GFCI instead in a regular old wall outlet in an older house with no Ground for return of abnormal leakage current DOES provide a different means of cutting off all power IF current leaks out of the intended circuit and fails to return fully on the Neutral line. It does NOT provide a Ground, but it does provide protection of people.

Sorry, that's rather long. It's not simple. But it is only the basics of this stuff.
 
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Feb 4, 2009
29,935
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Knob & tube wiring needs to be replace and replaced in full.
This doesn’t need to be a priority but it needs to get done.
I know there are safety reasons to replace it and I also understand the fact that it has been there so long it has proven itself safe.

Here’s the problem:
As it ages it becomes more of a risk
Sale of a home with knob & tube will be problematic
Insuring a home with knob & tube will be close to impossible or it will come at a huge premium.
Getting a home rewired is less money than many people expect, especially if you are willing to repair the trim, drywall (likely plaster) and or trim and are willing to paint. Electricians hate doing this work for whatever reasons.
If the electrician is going to leave the old wire have them remove the ceramic post thingies that knob & tube has. Not because the inactive wire is dangerous but because you don’t want a potential buyer to see them and fear there is active knob & tube.
 
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Steltek

Platinum Member
Mar 29, 2001
2,816
594
136
If you are able to verify you don't have any asbestos problem in the wallboard and plaster, it might not be hard to re-wire most of it yourself one room at a time with simple circuits (provided you can get whatever permits you need and are able to fish wires down into the walls from the attic to the outlets). I wouldn't do this, though, if you plan to sell the house - in that case, have a licensed electrician do it so you don't have liability.

If you decide to try to do it yourself, Wago wire lever nuts are a gift from the electrical gods for use in junction boxes. I literally do not know how I EVER lived without these things. They finally began selling them at our local Home Depot, previously I had to order them online from Amazon or Menards (who stocked them but doesn't have stores in my area) in order to get them. They make the lever version and a push connector version - even though they are more expensive, I only use the lever versions as they are better in every way that counts.

They are UL approved wiring devices - the version pictured (Wago 221-412, 221-413, 221-415 are model numbers for 2, 3, and 5 conductor versions shown below - the connector itself is rated at 32 amps) works with #20 to #12 gauge wire (#12 being what you would want to use). If you have to pull a #10 gauge wire for a heavier load, use the more expensive #10 version (221-612, 221-613, 221-615 -- the #10 version works with #20, #18, #14, #12, and #10 gauge wires and connector is rated at 40 amps). Using them is simple as dirt - just run the wires into a junction box and strip the outer wire sheathing in the junction box. Strip the insulation from each conductor wire to the right length (there is a gauge on the side of the connector), open the lever, stick the wire in (one wire to a slot), and snap it closed. They are even transparent so you can see that the wire is where it should be, and have a test port for a multimeter. Use one connector for hot wires, one connector for neutral wires, and one for ground (or just twist all the grounds together with a green wire cap if you want to save money). No more sore carpal tunnel wrists from twisting multiple wires together, no wire caps to mess with. Literally, no muss, no fuss.

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Greenman

Lifer
Oct 15, 1999
17,308
2,542
126
The foundation is really the bitch on this house. I wish I'd had the dough to take him up on his bid to fix the house. It would have included doing the foundation. I've had some of the best GCs around (back in the early oughts) look over that aspect of things and was told that getting after this house, starting with the foundation issue, I'd be putting money in I'd never get out. So, I tabled that. I figure I should just move/sell! Easier said than done. It's sure a seller's market right now!
Thinking about this a little more, the one thing you don't want is for your house to become a teardown. At that point, the only value is the lot.
 

Red Squirrel

No Lifer
May 24, 2003
59,685
8,599
126
www.uovalor.com
Sounds like there's so much work to do, you need to decide if it's worth it for you to do it or it. Ex: realize you probably will never get that money back if all you care about is resale value, but if it will make it better for your own enjoyment then that is worth something.
 

Muse

Lifer
Jul 11, 2001
30,186
3,573
126
Thinking about this a little more, the one thing you don't want is for your house to become a teardown. At that point, the only value is the lot.
That's something I pretty much think about on a daily basis. Now, I did start buying EQ insurance around 3-4 years ago, but I don't have confidence or understanding of what would happen if the house suddenly became a tear down. The lot is probably worth quite a bit ATM, but I figure (just rumination here, I have no data or exposure to info on this) that after a "major earthquake" here the value of the property (lot included) might be poof!
 

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