120V, 49V, 51V on outlet test and hot ground

[WSP]

@bgard and @jadnashua thanks for the additional thoughts. i may start with the 3-way switch and see if i just get lucky. back to the topic of AFCI-GFCI's though. anyone think that if i installed those, i'd not have a safe situation, if i opted to finish this remodel otherwise, before correcting the wiring?

 

[Bgard]

the three-way switch wiring that I was describing was called (the carter system) in which each switch has the hot and neutral connected to the traveler terminals and the common terminal from one switch goes to the shell of the light socket and the common from the other switch goes to the center terminal of the light socket. this method was banned in 1923 because of the risk of electric shock because the shell of the socket may be hot with the switches in certain positions. I believe this is what you have and your problem may be at one of the light fixtures with the shell of the socket touching what should be grounded if it is not properly bonded to the entire system iit will now become hot if it were properly bonded/grounded it would trip the breaker. you may not have 120 volts on it because of poor connections but it could still be enough to shock you. I don't know how extensive you remodel is but now would be the time to rewire if you are planning to open any walles. it would probably be better to spend money on the things that could kill you or a family member or cause the house to catch on fire after you spend a bunch of money on things to make it look pretty. just my opinion

 

[Sponsor]

 

[WorthFlorida]

With this old home I would not use any electric space heaters this coming winter. Here is a post of old BX wiring where by flex duct melted from a hot ground. It was found that the neutral and hot wires were reversed.

https://terrylove.com/forums/index....causes-buzzing-noise-and-burning-smell.68359/
You may never know what lies in old homes.
https://terrylove.com/forums/index.php?threads/what-monkey-wired-this-outlet.68530/

 

[WSP]

Thanks for the further words. Seeing the myriad potential problems that could exist here is making me want to either replace all wire and put in new switches and outlets everywhere that's original cables, or at the least call an electrician and go ahead and put in AFCI/GFCI's for a little extra peace of mind. We had a house of similar age as ours burn on this block due to an electrical fire in the attic, and I'm pretty sure another's attic fire, across the street, was probably also from electrical issues. Feel like we are living in a time bomb, now : )

 

[Jadnashua]

IF you've got the problems you indicate, you probably wont' be able to keep a GFCI from tripping. ANd, the AFCI may trip as well! It would be interesting to find out.

A good portion of the house I grew up in had BX and plastered walls...really hard to fish new wiring. But, to make things a bit safer, I ended up removing all of the receptacles and replacing them with a GFCI at the beginning of each run. This required tearing out all of the receptacles, locating what was the beginning of the run so I could place the GFCI there. After over 50-years, the existing receptacles were pretty much worn out. In one case, I tried to measure from the neutral to the BX...it read nearly open...corrosion over the years was evident with slight rusting of the connection to the box. A few areas had newer wiring, but most did not have grounds...the GFCI was the least expensive way to make things safer. If you do not have a valid ground, and you install 3-wire receptacles, it's legal, but each one must be labeled as "GFCI Protected, No Equipment Ground", or something similar...the GFCI's came with a bunch of labels for things downstream.

 

[WorthFlorida]

I love the old homes in the NE and one time we owned a home in Saratoga Springs, NY, but old homes does have its problems; old wiring, lead paint, perhaps asbestos, old heating systems. With your concerns be sure your smoke detectors are working and maybe add a few. Current code requires one outside of each bedroom or hallway of bedrooms, inside each bedroom, and at the bottom and top of stair wells. My current home in Orange County Florida has seven smoke detectors for the three bedroom, two story house.

It doesn't cost anything to ask an electrician the cost to upgrade. Perhaps an electrician may do what Jim suggest to buy you time. Then call your insurance company and ask if would there would be any kind of discount with new wiring. In Florida, a new roof will discount a few hundred dollars for several years since new roof will result in less claims. On a rewire have the smoke detectors hard wired if you have battery operated ones and add them to the project. Hardwired ones are wired on one circuit with 14-3 wire and the third wire (red) are all connected to all of the smoke detectors so if one goes off, they all sound off.

 

[WSP]

Try the measurement again when you get a 120/49/51 reading.

Hi Reach4. Found the outlets reading funky again today. Measurements: hot to water pipe: ~121V, neutral to water pipe: 0.0V, ground to water pipe: 34.5V. The prongs are around 121/50/50. Any further thoughts give this? Also, I measured 35V from the surface of a metal-clad cable in the basement to a water pipe—expected, given the above—but also unsettling. This means I'd be getting >35mA of shock if I grab these things with wet hands, I guess. That's not good, right? Also of note: this reading is with OR without the ground bridge connected that I mentioned previously in the thread. And last thing to note, with the other 'suspect' circuit off, it has no effect on this dangerous situation. I'm guessing somewhere there's a bare wire touching the cladding or a box, and I should probably turn off the breaker, for good and get to the bottom of the problem. Thoughts?

 

[Reach4]

I mis-read....
It sure looks like a bad connection in the neutral path, don't you think?

Run around and check other neutrals. Note bad ones. Then figure out if they are on the same circuit or different circuit.

Note that your neutrals in the old house may be shared between two circuits (MWBC = multi-wire branch circuit). So take that into account.

 

[WSP]

I love the old homes in the NE and one time we owned a home in Saratoga Springs, NY, but old homes does have its problems; old wiring, lead paint, perhaps asbestos, old heating systems. With your concerns be sure your smoke detectors are working and maybe add a few. Current code requires one outside of each bedroom or hallway of bedrooms, inside each bedroom, and at the bottom and top of stair wells. My current home in Orange County Florida has seven smoke detectors for the three bedroom, two story house.

It doesn't cost anything to ask an electrician the cost to upgrade. Perhaps an electrician may do what Jim suggest to buy you time. Then call your insurance company and ask if would there would be any kind of discount with new wiring. In Florida, a new roof will discount a few hundred dollars for several years since new roof will result in less claims. On a rewire have the smoke detectors hard wired if you have battery operated ones and add them to the project. Hardwired ones are wired on one circuit with 14-3 wire and the third wire (red) are all connected to all of the smoke detectors so if one goes off, they all sound off.

Indeed we have inherited a ton of issues with this charming house. Many hack renovations over the years, for start, but compared to the old wiring, I think the other work is harmless in comparison. Thanks for all of the suggestions.

 

[WSP]

It sure looks like a bad connection in the neutral path, don't you think?

Run around and check other neutrals. Note bad ones. Then figure out if they are on the same circuit or different circuit.

Note that your neutrals in the old house may be shared between two circuits (MWBC = multi-wire branch circuit). So take that into account.

I'm not sure I'm qualified to say.... What makes you suspect, exactly that it is a bad neutral? Do you mean shorted on ground, or just disconnected somewhere?

 

[Reach4]

Sorry. I made a mistake when I said bad neutral... I mis-read. I somehow thought you wrote that you had 34 volts from the neutral to the water pipe ground. You were clear, but I missed it. You have a bad ground path going back to the grounding strip on the breaker panel. That could be a bad connection in that box or in other boxes.

 

[WSP]

Sorry. I made a mistake when I said bad neutral... I mis-read. I somehow thought you wrote that you had 34 volts from the neutral to the water pipe ground. You were clear, but I missed it. You have a bad ground path going back to the grounding strip on the breaker panel. That could be a bad connection in that box or in other boxes.

Isn't there something worse than that going on? I shouldn't be getting any voltage that large from wired ground to water main, should I? Maybe if you could be more specific I'd understand what you mean. By bad ground path, do you mean there's just a missing ground on an outlet or switch somewhere?

 

[Reach4]

There should be a good path to the ground terminal that you are watching. Your path is lacking. How alarming is that? Depends on your point of view.

Here is a test for you. Try measuring the voltage between the hot terminal and the ground line. If there was really a solid 34 volts on the ground, you would expect about 86 volts from that ground to the hot. I expect you will get a fair amount less. If not, that will be significant.

Your meter is high impedance. So it does not take much current to indicate a voltage on the meter.

Connect one probe of the meter to the water pipe ground. Hold on to the metal on the other probe with your fingers without touching anything else. What does the meter say? Are you alarmed? Don't be. Move your other hand near various things. Does the reading change?

 

[WSP]

So latest is this: I solidified grounds on all the outlets and switches on the circuit. Now I read 118/49/49 on outlets on the circuit, and 50V from an outlet ground pin to a radiator pipe. 0.1V from outlet neutral to the radiator pipe, as well. And the hot to radiator is the full 118V. So seems like there's still a ground problem somewhere, huh? I am going to continue looking for any sketchy grounding situation in the junction boxes I find, and hope that some fix is going to have the ground suddenly acting like a ground.

 

[Reach4]

Now I read 118/49/49 on outlets

What are those three numbers representing?

 

[WSP]

What are those three numbers representing?

It's hot to neutral, hot to ground and neutral to ground. Measured form any outlet on the circuit.

 

[Bgard]

it sounds to me like you have an open neutral somewhere it the circuit and the 49 volts is from something in the circuit looking for a good nuetral

 

[Reach4]

How is the protective ground (grounding conductor) connected to the outlets from the breaker box?

Maybe one of the earlier posts said it, but I did not see it in a quick look back.

 

[Jadnashua]

Copper water pipe may or may not be a great ground, there could be a section of plastic pipe, a connector, maybe a water filter or water softener or who knows what in line before it can make it outside and be a decent potential grounding point. The only grounding point that is important is the one at the power panel. Now, you often bond things like the metal pipes to that ground, but generally, you should not rely on them as your grounding point. Even the soil may not be a very good grounding point, depending on its composition, the moisture content, and probably other factors. For example, dry sand makes a lousy ground point. Way back when I was in the military, on field exercises in the desert, they would requisition large quantities of table salt, mix that into the soil where they needed a good ground, and keep it wet. This improved both the electrical safety and the performance of things like antennae, since it then provided a decent ground plane as well. It can sometimes take numerous ground rods to get a decent ground in parallel to get the resistance down. Pull the breakers out of the panel and look at the bus bar and their contacts. If they come out easily, over time, the heating/cooling from changes in load may have made their spring contact pressure too low to maintain a good connection. There could be some arcing or corrosion there as well.

Have you checked the connections in the main panel for tightness, arcing, or corrosion? Sometimes, just a loose connection can be a source of all sorts of weird indications.

 

[SteveW]

I wouldn't recommend a homeowner who is not very experienced with electrical work open the breaker panel.

Time to call an electrician.