Thanks for the additional ideas. The non working outlet has both hot and neutral connected. And I know how to use a multimeter. It's auto ranging, so the only thing to select is AC or DC, so I think I got at least that part. I wish it was that simple : )

Ok then. Before you go any further with testing, try to figure out why you are reading 27VAC at a working load (i.e. incandescent light bulb). Something is not correct right there.

 

Ok then. Before you go any further with testing, try to figure out why you are reading 27VAC at a working load (i.e. incandescent light bulb). Something is not correct right there.

I'm obviously not an expert, but I do google a lot, so I think it's called "residual" or "phantom" voltage.

https://diy.stackexchange.com/quest...-16-volts-on-a-wire-that-should-be-at-0-volts

https://diy.stackexchange.com/questions/126446/light-outlet-reading-80v

https://diy.stackexchange.com/questions/24522/why-do-i-only-have-30v-going-to-my-light-fixture

and more on this forum as well if you search...

 

None of those links help.

If you connect an incandescent lamp to 120VAC the lamp should light.
The voltage across the lamp should still read 120VAC.
If the lamp glows at full brightness and the reading is much less than 120VAC then something is not quite right with the measuring equipment , meter probes or connections where the measurement is taken.

 

Yes. I started at that one outlet. And, yes, it is controlled by a switch. The switch interrupts hot. Neutral wire is not even cut at the switch (only hot is) and neutral wire just goes right through to the outlet. Both switch and outlet visibly seem fine and use screws (not push in). Outlet gets no power when switch is off. It gets 27v when switch is on. But several other switches and outlets in other rooms (on the same circuit) also get 27v. My research tells me theres a loose neutral *somewhere* on the circuit. Everything is old, but a few devices have been "upgraded" by the house flipper, some of those were backstabbed to daisychain within the box. The ones I replaced so far made no difference.

Is the problem A) or B) or C ) ?
A) with the AC Power entering into the Switch Box ?
B) The switch itself ?
C) The power leaving the switch box and arriving at the Outlet box - ie in the wall?

A) Do you actually have 110 V AC incoming to the SWITCH BOX ?
1) Turn AC Power OFF at the panel
2) CUT the White / Neutral wire inside the Switch Box
3) Connect your Meter Probes between the INCOMING Neutral ( White ) wire and INCOMING Hot ( Black ) wire
4) Turn AC Power back ON at the panel
5) Does your meter read 120 V AC ?

If you have 120 V AC power coming into the Switch Box then ...

B) Is the SWITCH BAD ?
1) Turn AC Power OFF at the panel
2) Remove the Switch
3) Reconnect both Neutral (white) Wires together - wire nut & tape
3) Connect both Hot (black) wires together - wire nut & tape
4) Turn AC Power back ON at the panel
5 ) Plug in a Load into the "bad 27vac" Outlet and measure the AC Voltage on the outlet screws.
6) Now do you have AC power arriving at the switched Outlet ? If yes, then BAD switch

C) Bad wire inside the wall ?
If the Switched Outlet still does not work then you have a bad wire between the Switch Box and the Outlet Box


Divide and conquer ...

 

I know where 60 VAC comes from, but not 27 V.

With 60 V, it can come from a RFI filter in a PC that is feeding a ground that is disconnected. The shunt resistance of the capacitor model act as a 1/2 V voltage divider, so you get about 60 VAC. You cannot draw appreciable current. Maybe 50 mA max.

Voltages can couple capacitively.

LED lamps typically have two connections, so that's out.

You have expensive options like the Ideal Suretrace and the wallabot.

I did, once drive a nail into Romex between ground and another conductor. nail plates are supposed to be used where that is possible.

I've never seen soldered wires.

Rewiring. My experience is the 1960's. Romex was run to the metal outlet boxes and the outlets were polarized Nema 1-15's.
At least the ground was run. There was no ground screw in the outlet boxes.

Outlet upgrades, which eventually occurred everywhere. The last room which was painted was a badroon and the outlets became tamperproof Decora.

You have to ground the box and the outlet. That can be difficult.

The re-wire method I used in general is no longer available. I used Ideal term-a-nuts which came in blk, wht and green with a flex wire coming out the small side of the wire nut, Fork or stripped wires were available.

They were great. The hots and neutrals for the lamps were stripped ends and for the outlets, the fork terminals.

Ground gets tricky. A wire was usually wrapped around the romex screw. Sometimes the grounds were not wire-nutted. This was a source of one difficult problem to find. Tightly twisted grounds, but no wirenut. The wirenut creates a gas-tite connection. Watch for that/

The ground clip only accepts solid wire. If you can tap a ground screw, that's great. The clip is hard to install

Then it becomes a solid ground stripped pigtail from the side of the box to the unwrapped ground. Use a green term-a-nut to add the ground pigtail. There are green wirenuts with the hole or solid wire in the center though.

You MUST ground the outlet and the box. You cannot relay on the outlet to box screw.
Certain outlets can be used will allow that though,

In Tamperproof outlets, the Hot and N must be pushed in simultaneously so kids can't insert an object like a key.

GFCI's are allowed for 3-prong non-earthed outlets PROVIDING the outlets are marked "No equipment Ground". Your not allowed to run a separate ground to ground an ungrounded outlet.

Back in 1947, there may exist some non-polrarized outlets. Be careful there, too.

 

mvas - Thank you for the step-by-step troubleshooting. I will not be able to start testing again till Friday for several logistic reasons. Today is Tuesday. Just gathering as much info as possible for now. Bought smoke alarms for each room and corridor (which should have been there to begin with) to get by for the next 2 days. One of the more interesting things is that I've measured 27v on several other switches in different rooms and they are connected to working lights. I will chase the circuit and do a detailed breakdown of what measures what on Friday.

K.I.S.S. - Thank you for the post yesterday that explained testing from the middle. And thank you for following up today. I actually first measured 61v, but every time after that I've been measuring 27v, so I haven't even mentioned 61v not to confuse people. The only computer is a laptop on the outlet adjacent to the one that's completely non-working. I will look into the possibility of a PC cap "dividing voltage", interesting concept, if nothing else.

Both of my houses, same vintage, next door to each other, have these neutral bundles inside of jboxes, they appear soldered or welded together and then taped over. Local electricians told me before these are common. Perhaps just in the Pacific NW area? I had just completed rewiring my other house, which is single story, and I am not rewiring this second one. No way. But I will attempt to at least fix the problem. I *must* fix it really. Both houses have only hot and neutral and no grounds. Even GFI outlet in the bathroom appears to be "grounded" just for looks as I saw no 3-wire cables in the main panel. I have no idea where the ground wire terminates and would not be surprised if it ends up being tied to neutral somewhere. Will double-check on Friday.

The house flipper apparently Mickey Moused this house because they knew that I would buy regardless because of my property next door.

Keep them ideas coming, everyone, highly appreciated. I realize that it will be 2 more days till I can do anything about it. But knowledge is power and I'd rather start troubleshooting well armed. So anything else that anyone has in mind, don't hesitate to post it up, I greatly appreciate it. Many thanks in advance again.

 

Both of my houses, same vintage, next door to each other, have these neutral bundles inside of jboxes, they appear soldered or welded together and then taped over

That was the normal thing here in NE Ohio too.

 

I will chase the circuit and do a detailed breakdown of what measures what on Friday.

One more suggestion and it may seem weird.
Since it appears only the one outlet is not working and is controlled by a wall switch, turn on all the wall switches on the circuit and see if there is power.
SG

 

Take a look here https://www.mouser.com/datasheet/2/418/NG_CS_1654001_CORCOM_PRODUCT_GUIDE_0611-774752.pdf#page=17.

See the two caps to ground? That's where 1/2 * 120 V can come from.

I have no idea where the ground wire terminates and would not be surprised if it ends up being tied to neutral somewhere

it is supposed to be. Neutral is supposed to be tied to earth at only one place unless a detached structure is involved. Sub-panels generally need a ground kit. The two panels are "main breaker" and main lug. The main breaker panel needs extra parts and some re-configuration to become a sub-panel.

27 is about 1/2 * 48 V, but that should be a DC voltage from the telco system. Don't overlook telco and cable. Odd things can happen if neutral finds a different path to earth like via the neighbor;s house.

 

OK, took voltage measurements on all outlets and switches that are on that one 15A AFCI breaker circuit tonight.

An interesting observation is that 90% of switches read approx 120v when OFF and 0v when ON - which seems consistent with what my electrician mentioned about old houses "bringing power down" from light fixtures.

I will need to check which switches just interrupt hot. Possibly all of them. It's too late to think now.

There are 8 outlets, 11 two-way switches (1 for the bad outlet, 10 for lights), 4 three-way switches (for 2 lights), 12 light fixtures (2 of which have wobbling sockets, 1 splits to 2 fluorescent tube lights with no bulbs currently).

The 2 "wobbling" light fixtures are both in closets. One of them reads 12v OFF and 120v ON at the fixture. The other one reads 29v OFF and 120v ON at the fixture. Their switches are 120v OFF and 0v ON like most other switches. Did not check the rest of light fixtures as they are LED modules and I was short on time to undo the wiring tonight.

Most outlets read around 120v. One GFI outlet is 123v. One outlet seems crappy and I got both 120v and 80v readings depending on how much I wiggled it (and possibly it's the last one on that whole entire breaker circuit). Hmm.

The "bad" outlet that started my quest is in the same room as the 110v/80v one. Hmm. So possibly towards the end of that breaker circuit. This "bad" outlet reads 42v OFF and 26v ON. It is controlled by a switch above it that reads 42v OFF and 0v ON across 2 hot terminals (that switch only interrupts hot). I did not measure from hot to neutral on this one because I was in a rush and forgot.

One suspect switch is in the bathroom, it goes to 2 fluorescent tube lights without bulbs, switch reads 68v OFF and 0v ON and is backstabbed. I think it makes sense to replace this one first.

Both three-way switch circuits are also suspect. One circuit reads 105v OFF and 35v ON at one switch and 111v OFF and 35v ON at another switch. Both switches look crummy and need replaced. This three-way circuit seems to be st the very beginning (closest to the breaker panel). The second three-way circuit reads 120v OFF and 24v ON at one switch and 122v OFF and 26v ON at the other switch. This three-way circuit is approximately in the middle from breaker panel. These switches were the only ones I replaced with new on the first day I poked around.

I will draw a little picture (since I can not use my hands) to try and explain this better, tomorrow at work, will post the diagram during the day sometime. I'm crashing now. Big thanks for bearing with me.

Are we having fun yet? : )

 

I see red flags everywhere.

Your readings should either be 120VAC or 0VAC plus or minus a few volts.

You state a voltage reading at a switch, light or outlet.
You do not state how you are taking the reading.
To what two points you are connecting your meter in order to take the reading?

Edit: Rereading your last post, I can assume that you are measuring across the switch, light and outlet.

1) Across the switch. With the switch off you should read 120VAC only if there is a load at the end of the line. If there is no load you are reading stray voltages. It should read 0VAC when the switch is on.

2) Across the lamp, you should read 120VAC when the lamp is on and 0VAC when the lamp is off.

3) Across the outlet, you should read 120VAC. If it is a switched outlet, you should read 120VAC only when the switch is on, 0VAC with the switch off.

 

Thanks. That helps. So where do these stray voltages come from? A loose neutral? Or is a bad device still a possibility?

 

Thanks. That helps. So where do these stray voltages come from? A loose neutral? Or is a bad device still a possibility?

Safely remove both Black Wires from the "controlling" Switch & tape.
Restore power and measure the voltage at the "controlled" Outlet.
Voltage still there or gone?
Is the Switch smart or dumb?
Does it have internal lighting?

 

Thanks. That helps. So where do these stray voltages come from? A loose neutral? Or is a bad device still a possibility?

Stray voltages come from having any wire running side by side along a hot wire. You do not need electrical connection anywhere on the "floating" wire to pick up a voltage. Hence bad or working device can still pick up this "stray" or "phantom" voltage.

If you have an unconnected NEUTRAL wire inside a cable where the LINE is live then you will measure this stray voltage.

 

Here is how you can eliminate "stray voltage" readings.

Get a power bar and plug it into the suspected circuit. Plug into the power bar a low wattage incandescent night light (4W or 7W) or a low wattage house lamp (e.g. 25W). The light bulb will remove any stray voltage when power is supposed to be absent.

If there is power present, you ought to read 120VAC across the any of the outlets on the power bar AND the lamp must light at normal brightness.

 

There is something you can do when measuring outlets. Hook up a 120 V plug securely to your meter. Have a 120 V plug, preferably a large one.

Insert the metered plug into one outlet and insert the other in the vacant duplex outlet. Wiggle the unconnected plug while observing the meter.

If you have help, or if you have a long extension cord, plug the cord into the furthest outlet and bring this point to the outlet your measuring. So, your looking at the end outlet voltage while wiggling a plug in an earlier outlet. Definitely wiggle both top and bottom. I never tried these methods.

It work, I did discover an open ground at an outlet. Taking the outlet apart, the ground was made with friction only between brass and a plated metal. You could see the arc marks. There were 420 outlets in the building, now all suspect as being bad. Lab outlets got replaced with a different color (brown vs Ivory) - no questions asked.

At the same time it was found that hall outlets, which were used for buffers, shared the lab outlets. Those were marked with large red dots so the janitorial staff would not use them.

The office outlets as needed or checked when computers were installed. I had an outlet tester at the time which had a gnd light that illuminated if the ground connection was <1 ohm. Inserting a power cord (nothing connected) and the outlet tester and wiggling the power cord would reveal the defective outlet. The devices were swapped and the test repeated.

The electricians did not want to replace all of the outlets or even test them. They didn't even come up with the test.

Aside:
It's hard to find bad connections with Ethernet cables that show up when the cable is flexed. The tester I obtained a while ago for Ethernet glowed red or green to show if the cable was straight or crossed. Simple LED type test. Wiggling would cause the LEDs to extinguish.
I did make a remote for the device too.

The tester was also unique because you could cut each wire with a switch and have access to both sides as test points via a machined pin IC socket.

 

Thanks, everyone, I will try all of the above suggestions mentioned yesterday and today, but probably not till Friday, I will only have an hour or less after work tonight if I dont want to end up sleeping in a doghouse. I might change a couple obviously crappy outlets and switches either tonight or tomorrow to see if that changes anything. All switches are toggle, not smart, not lit. Several switches and outlets were very obviously 30+ years old and crummy as all hell, so might as well replace them, just a matter of finding time.

 

I am attaching my crude diagram to provide a visual. Note that top row has switches inside jboxes and bottom row has all devices separate. I am not 100% sure on the exact path at this time yet, so it might be Bedroom-2 at the very end or it might be Bedroom-1. Also, switches appear to interrupt hot, I only measured across switch contacts and not hot-to-neutral. Will do additional test and measurements later.

 

Also, switches appear to interrupt hot,

Which is the way they should be, never switch the neutral only, I've seen old houses where people over the years did that. Not safe or to code .

 

Here https://www.bhg.com/home-improvement/electrical/switch-wiring/ is a useful URL.

1. Shows the wierd helpful ground wiring nuts
2. A reminder that white wires need their ends taped black when used as a hot wire.