This house I’m working on, so happens to be where I live too.

I know there are two meters. One of them should only meter power to one apartment. The other is for the second apartment and the rest of the house.

The second meter services, or at least should, my issue.

A) an UPS says wiring fault.
B) could be on a sub panel. (Where ground and neutral shall not be on the same buss).
C) 120 volts on ground to ground when tested to an different outlet. (Will test with ground to other prongs tomorrow.)
D) short ground and neutral wire does not spark.
E) swapped black and white wires. UPS still said wiring fault.
F) 120v between ground and white. (Yes, contradicts D.)
G) 0v between ground and black.

If I had hair, I’ll be pulling it out. Unless I am missing something so obvious that I cannot see it.

The only thing that I could think of. Is that this ground is really not connected at the panel. But between the outlet I am working on, which is first of 4 devices... 2 outlets and 2 switches which are in a single gang box and the panel is something I don’t know. There could be something plugged in that uses all three prongs. And there is a component (diode maybe?) that is connected between neutral and ground. And that’s putting 120v to the ground wire? But why does nothing happen when I touch ground and neutral?

I had to walk away from it because of the head scratcher.

I already discovered that there are 2 other outlets that should be on all the time. Are actually connected to the light dimmer for the sconces. Yes, dimmers. So I’ll be installing switches in where the dimmers are. Easiest and cheapest fix, house going on the market.

If there is anything else that I missed that I could test. Let me know.

KOT

How old is the house?

c) and D) tell the story.

You can check me on this, but I suspect that if you connect a long run of wire that is not connected to anything except your voltmeter and the other lead of your voltmeter is connected to an actual ground, you'll read a surprisingly high voltage, possibly 120 or whatever the voltage is in your area. The length of wire will pickup nearby electric fields and the meter will indicate this potential. High quality meters will read a higher voltage than low quality meters. Even though there is potential, there is virtually no energy available. If you place a resistor in parallel with the meter, even your body -- if you are sure that the wire is isolated. The resistance will dissipate the energy and your voltage reading will be at or near zero.

If you have an unterminated run of speaker wire, you'll probably measure near 120V between the wire and a ground.

Conclusion: the ground wire is connected at the outlet, but there is an open at or near the panel.

You could approach this "proof" another way if you like: connect a resistor between neutral and ground at the outlet. The value is not very important. Measure the voltage across the resistor. it will be very low or zero. Now measure the resistance. It will be whatever value resistor you used, but should be near zero if there was a ground connection at the panel.

I was thinking that the ground was not connected at the panel as well. I just had to confirm it with someone else as I never ran into this before.

To be honest, this house is a mess all around. Electrical, plumbing, and many other things.

I can't count how many electrical issues I've discovered. Most of which are simple things. So I know this house wasn't build by a licensed person. I mean, who leaves out the cable clamps going into the boxes? Especially on an outdoor light that is suppose to maintain watertightness.

TouchCommandor... I understand the house was bought in the mid 70's. Torn down in the late 70's to early 80's. Rebuilt into a house that is 2 or 3 times larger than the original. As far as how far down it was torn down, I don't know.

KOT

Call a good electrician- these places have some dangerous problems and I would stop working until they have been repaired.

A diode would do nothing if it was connected between neutral and ground- they're used in power supplies to rectify AC into DC (with a lot of ripple), not to create AC. The neutral and ground should have no voltage between them and the neutral is mounted to the breaker panel's enclosure, where it meets the ground. If you saw 120VAC between the grounds at two outlets, DO NOT use both for equipment that will be interconnected unless you want to see smoke. Those are on separate circuits and this problem could be lethal.c

This looks like someone did some electrical work but didn't understand how it's supposed to be done. FYI- many states now require common areas to have their own meter and breakers, to prevent arguments between occupants. The circuits are required to be totally separate, but wired correctly.

Tester could help?

[Link: testequipmentusa.com]

+1 Highfigh

You need to find out the problem and correct it berfore someone gets hurt or worse

There's so much possible advice that I can't even start. Hell, I just deleted five paragraphs.

Make no changes until you have measured everything and written it down. Then take that list of stuf, sit down, and put it in some kind of order, like neutral to ground, neutral to hot, hot to ground, at each panel... so you have a big table of information.

But before you go any further, locate an ACTUAL GROUND. I mean in the ground. A metal pipe that does not connect anywhere to any PVC pipes. NOT a gas pipe. And measure the voltage between that ground and the electrical box. And the neutral bar. And the ground bar. Of each panel. (And measure from electrical box to electrical box!)

Make a list of what things you measured, from what to what, and what the result was. This list will eventually point you to the problem.

But don't try to make ANY corrections until you have measured everything and you can see the overall picture.

And keep one hand in your pocket whenever measuring. And remember that the good job on the old electrical train is being the engineer. Be the engineer, not the conductor.

And keep one hand in a pocket every time you make a measurement.

That's fine if the person looking for these problems is an electrician, but in most places, non-licensed people aren't doing this work. It seems that this place is an electrical nightmare.

Agreed. In fact, all of this information is not only fine, but absolutely necessary if the person attempting to do this work is NOT an electrician. For them, it is even more important for them to be told the depth of possible confusion and the amount of information it might take to figure it out.

If that discourages them, then they'll be guaranteed not to kill themselves or perpetuate the problems that are there now.

Since deadly levels of electricity are involved, if this discourages the amateur, well, that's a good thing.

Definitely invest in one of these. I always plug test receptacles as the electrician may have the breaker off or not connected yet within the panel (especially within new houses).

Sounds like a lot of the wiring is completed with old 2 wire without a ground. We run into this quite a bit around here with houses built within that time frame. The proper way to protect this (without running all new wire) is to add a GFCI receptacle. I don't know if that will solve the fault problem the UPS is showing (it should) but at least the receptacle is safe.

I would definitely be calling an electrician in to look into the wiring of the house. They should plug test everything and take apart any receptacle that doesn't properly to find out what is happening. There problem may be as simple as a broken ground within the panel or as advanced as the whole house used un-grounded wiring.

As for the receptacles being on with the dimmers, this was also done a lot around here back in that time frame with switched receptacles for lamps. Usually only 1/2 the receptacle was switched and the other half had constant power. Simple fix is to replace the receptacles and wire the switch wire together and leave it capped in the box.

The $hitty work we see from old houses and home owner electricians is astonishing and is surprising that the houses are still standing with the amount of fire hazards or almost fires (seen arcing in boxes with now covers sitting in insulation).

I think that anyone who wants to tackle this is ignorant of the real possibility of danger, over-confident in their knowledge and ability or knows exactly what they're getting into but the latter would most likely be a journeyman or master electrician. Electrical engineers may know the theory, but I know of one case where an EE wired a garage and switched the neutral on the 3-way switches, which resulted in the metal siding (and any metal touching it) to be hot when the switches were set in specific positions. That was an interesting tingle- glad I was on concrete, rather than the lawn.

For the others, it's unlikely that they would understand the principals of proper grounding, bonding and the need for maintaining correct phase in each circuit.

At least this doesn't involve >400VDC, as it can in equipment that uses tubes. A slight jolt of AC can be exhilarating, but under the right/wrong circumstances, that can be lethal, too. I have heard that getting slammed by plate voltage is extremely painful.

I would add that the ceiling junction boxes should be tested- my house has aluminum wiring and when I was revamping it, I removed the fixture in a hallway, wire-nutted the wires for later and lost the outlets on half of one floor. When I installed the new fixture, I found that one of the neutrals had broken when the wire nut went on and stripping it to expose new wire fixed the problem. If someone decided to replace outlets and/or switches, install a 3-way switch or add a sub-panel, it could easily cause these issues.

Working on a house that has splices in LV cables that were covered by drywall- some were abandoned, some are still intact. The LV wiring is a complete clusterflop, with no actual head end. Some of the Cat5e was joined at a short 110 block in the basement and some is dead-ended in the attic, while others are dead-ended in other areas of the basement. Some of the original wiring was knob and tube, so that's another issue.

That was an interesting tingle- glad I was on concrete, rather than the lawn.


Good thing the electrician who originally wired it up didn’t use the foundation as their grounding point. And or the foundation had steel rebar.

The NEC allows the foundation to be the grounding point, I assume a rod has to be buried in the pour.

And if there were rebar installed, then all shall be bonded together anyways.

KOT

Been there.

In my teens, using a kit built scope with a simple two wire power cord, no grounding, I had the scope "floating" across the series inductor in an ancient power amplifier's plate supply that I was probing. While contemplating the trace, not touching any part of the circuit, I placed one elbow on the scope's chassis and the other elbow on a signal generator.  !*! B+ across the elbows! I always observe the one hand in a pocket rule. I was ... er ... shocked that I was shocked. My elbows are still buzzing a bit from that one.