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electrical mystery of the day - two switches, no neutral
Posted by: mattkime
Date: May 26, 2020 10:39PM
2 gang box with one fan control and one light switch (exterior light) on the first floor. Two romex cables come in. One corresponds to the light - its white lead is hot and black goes to load. The other romex controls the fan - black is hot, white is load, and there's a red lead with a wire nut on the end. Who knows what that does. Everything is grounded as appropriate. I go to the basement and easily find the romex pair which snakes across the basement ceiling....and disappears back into the ceiling near the staircase. @#$%&! I was hoping it would terminate somewhere I could see.

There's a closet at the top of the stairs (2nd floor) that has a couple of junction boxes with plain covers. I could explore those. I could also flip switches at the breaker to determine whether the fan and light are on the same circuit. If they are - why the hell did someone wire it this way??

I'd like a neutral in the box so I can wire up smart switches. While I'm at it I'd like the wiring to be rational. There are clearly enough wires although I don't necessarily understand where they go.

Any tips for making sense of this?

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Additional info - I think the wires take a rather circuitous path to get where they need to go. I should figure out if the light and fan are on the same breaker. I might also find two romex (one with a red lead) in a junction box and be reasonably sure I found what I'm looking for. I would be super impressed if the ceiling fan had new wiring as all the wiring in the room is original to 1927. There's knob and tube in the walls.







Edited 2 time(s). Last edit at 05/26/2020 11:21PM by mattkime.
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Re: electrical mystery of the day - two switches, no neutral
Posted by: neophyte
Date: May 26, 2020 11:05PM
I'll bet the red goes to another switch that also operated that outside light in a 3-way switch mode. I suspect that the original wiring layout had power going directly to the fixtures, and only later were wall switches added, so only 2-wire cable was used to merely carry the hot from the fixture to the switch and back up to the fixture. How old is the house?
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Re: electrical mystery of the day - two switches, no neutral
Posted by: testcase
Date: May 26, 2020 11:08PM
Black is the "standard" hot wire and white is the "standard" neutral (and green or bare copper is the standard ground wire). Red wires are normally used as additional hot lines (as are blue wires). The installer might have used a 12-3 or a 12-4 romex cable that was handy. I don't believe having "extra" wires would be a code violation (they might have been pulled for a future project). As long as the appropriate sized wire nut completely covered any bare copper wire, you should be OK.
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Re: electrical mystery of the day - two switches, no neutral
Posted by: Carm
Date: May 26, 2020 11:43PM
What testcase said. I have used the red wire to add a separate switch to turn on light in an inexpensive ceiling fan. No pulling cord required to turn on/off the light.

Check in ceiling fan junction box, the “extra” red should be in there. Unconnected.



Edited 2 time(s). Last edit at 05/26/2020 11:47PM by Carm.
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Re: electrical mystery of the day - two switches, no neutral
Posted by: mattkime
Date: May 26, 2020 11:57PM
Check in ceiling fan junction box, the “extra” red should be in there. Unconnected.[/quote]

That’s 20+ foot off the ground. Custom plaster work on the ceiling. I’m assuming the wiring through the ceiling is original until proven otherwise.



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Re: electrical mystery of the day - two switches, no neutral
Posted by: Racer X
Date: May 27, 2020 12:20AM
"While I'm at it I'd like the wiring to be rational."

smiley-laughing001

You should see the craptastic mess that is my home's wiring. And it isn't that old '67-68. At least the newish detached garage has its own 60A sub panel, and the home has a new 200 amp breaker panel @2002. Wired like a one eyed, one handed drunk electrician did it though. At least the home has 12 guage wiring and grounded outlets.



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The police have no duty to respond. See Castle Rock v. Gonzales, 545 U.S. 748 (2005) or Warren v. District of Columbia[1] (444 A.2d. 1, D.C. Ct. of Ap. 1981)
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Re: electrical mystery of the day - two switches, no neutral
Posted by: d4
Date: May 27, 2020 06:29AM
That phrase about "knowing just enough to be dangerous" comes to mind right about now.



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Re: electrical mystery of the day - two switches, no neutral
Posted by: OWC Jamie
Date: May 27, 2020 09:20AM
What you're finding is a common practice 20 years ago. When I was an electrician wiring new construction, you'd wire the power for the room to the ceiling light in the center of the room (or if closet lights are present, to there). Then go out to your outlets (if on the same circuit, such as in a bedroom and not separate like a dining room). Run a 2 wire Romex to each switch, simply turning the light on and off. No neutral is required by code to be in that box as you've found. I always ran a 3 wire Romex to the switches in case of a ceiling fan installation, and there was a neutral wire for future use. However we were in the minority in doing that- MOST electricians did it the cheapest way possible, with 2 wire Romex and no future expansion possibility.

Most straightforward method of getting a neutral there is to wire it from below from the basement since you've said it's a 20' ceiling. You don't have to use (and should not use) the power side of the Romex you run into that switch box but rather just wire nut it off - and I'd write a note what you did for future generations. smiling smiley



Good Luck!
Jamie Dresser
Other World Computing
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Re: electrical mystery of the day - two switches, no neutral
Posted by: mattkime
Date: May 27, 2020 09:38AM
Thats exactly how I was sizing this up, Jamie. Perhaps my next step is to determine the best spot to rewire, either finding an existing junction box or adding a new one.

>However we were in the minority in doing that- MOST electricians did it the cheapest way possible, with 2 wire Romex and no future expansion possibility.

Its interesting to think about this. I assume the reason less wire was used is because nobody could think of a reason why it would be used. The wire is cheap, the labor is expensive.



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Re: electrical mystery of the day - two switches, no neutral
Posted by: OWC Jamie
Date: May 27, 2020 09:46AM
The labor time was exactly the same it was 2x the cost for 3 wire vs 2 wire basically since it was less common. I know a lot of electricians that never used it they just ran another 2 wire if needed. Made no sense to me. I learned the right way LOL smiling smiley

quote=mattkime]
Thats exactly how I was sizing this up, Jamie. Perhaps my next step is to determine the best spot to rewire, either finding an existing junction box or adding a new one.

>However we were in the minority in doing that- MOST electricians did it the cheapest way possible, with 2 wire Romex and no future expansion possibility.

Its interesting to think about this. I assume the reason less wire was used is because nobody could think of a reason why it would be used. The wire is cheap, the labor is expensive.[/quote]



Good Luck!
Jamie Dresser
Other World Computing
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Re: electrical mystery of the day - two switches, no neutral
Posted by: C(-)ris
Date: May 27, 2020 07:42PM
Quote
OWC Jamie
The labor time was exactly the same it was 2x the cost for 3 wire vs 2 wire basically since it was less common. I know a lot of electricians that never used it they just ran another 2 wire if needed. Made no sense to me. I learned the right way LOL smiling smiley

quote=mattkime]
Thats exactly how I was sizing this up, Jamie. Perhaps my next step is to determine the best spot to rewire, either finding an existing junction box or adding a new one.

>However we were in the minority in doing that- MOST electricians did it the cheapest way possible, with 2 wire Romex and no future expansion possibility.

Its interesting to think about this. I assume the reason less wire was used is because nobody could think of a reason why it would be used. The wire is cheap, the labor is expensive.
[/quote]

Can you just tap off any neutral in the basement and run it up to the switch? I always thought it needed to be from the same circuit and had to be run from the light fixture back down.



C(-)ris
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Re: electrical mystery of the day - two switches, no neutral
Posted by: mattkime
Date: May 27, 2020 08:43PM
I'm sure a neutral could be overloaded like a hot. I wonder how thats accounted for in circuit breakers.

Quote
C(-)ris
Can you just tap off any neutral in the basement and run it up to the switch? I always thought it needed to be from the same circuit and had to be run from the light fixture back down.



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Re: electrical mystery of the day - two switches, no neutral
Posted by: OWC Jamie
Date: May 27, 2020 09:47PM
For what he's wanting to do - run a smart switch - a tiny neutral draw for that isn't going to hurt anything to be quite honest. Now if he were running a microwave or vacuum cleaner, then we'd talk. smiling smiley

But a smart switch? Not going to cause a problem.

Quote
mattkime
I'm sure a neutral could be overloaded like a hot. I wonder how thats accounted for in circuit breakers.

Quote
C(-)ris
Can you just tap off any neutral in the basement and run it up to the switch? I always thought it needed to be from the same circuit and had to be run from the light fixture back down.



Good Luck!
Jamie Dresser
Other World Computing
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Re: electrical mystery of the day - two switches, no neutral
Posted by: Cary
Date: May 28, 2020 07:23PM
The neutrals are all tied into the same bus bar. As long as the side gauge is appropriate, and doesn't overload the circuit, it doesn't matter where you get the neutral.
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