Please note this setup -
This is in a bathroom:
I want to replace the bottom outlet switch combo with just a smart switch which requires FOUR leads:
Line = power in
Load = power out to the light
Neutral = completes the circuit (needed for most smart switches)
Ground = safety connection
This is the way it is currently wired. Which wire would be the neutral for the new switch?
Hello KruseLuds,
DANGER OF ELECTROCUTION
If your device connects to mains electricity (AC power) there is danger of electrocution if not installed properly. If you don’t know how to install it, please call an electrician.
Remember: SAFETY FIRST. It is not worth the risk to yourself, your family and your home if you don’t know exactly what you are doing.
It is either the black or white coming from the one thick wire with the white insulation, but looking up color coding for your installation is not possible, since we would need the country, the year of wiring and access to the guidelines for that country and your.
And that is if there even is a color coding regulation at that time.
My best suggestion would be look at entry point of the two wires on the original switches and see if there are some indications.
@WallyR USA 120v built in 1942.
It is difficult to see the details from your photos. I would like to see a closeup of the wiring of the outlet with the switch. (Where do the black wires from the BMC connect (BX Metal Clad conduit)? It looks like a GFI/Switch outlet, but I haven’t ever seen one. A part number would help.
It looks like someone added GFI outlets a few years ago, but they are wired wrong. You only need one.
Do the wires in the BMC connect to a light or fan (likely the original installation)?
Also verify that the white Romex cable going off to the right comes from the fuse or distribution panel.
From here I can make a recommendation for your electrician.
The question is if the standard have been followed, but if it has, then this might help.
https://www.bradyid.com/resources/wiring-color-codes
The outlets are daisy chained, but it looks like the wire color was not maintained throughout the process. I’d pigtail off the main power line coming into the outlet box. AGAIN use a licensed electrician
It also looks like the power is either back fed to something else or the main power source was bypassed.
The red underlined push-in connectors are feeding another outlet or this outlet.
I’d bet they were added after the fact. I’d also 2nd @WallyR multimeter test suggestion, but I’d remove the outlets from the equation to ensure the power is back fed in a possible power loop.
I agree with @LiQuid_cOOled.
Disconnect before measuring.
It is a logical thing to do for me, so I did not mention it.
The outlets were added years ago when there were many girls living here with blow dryers and the electric was upgraded to 150 amp. The metal clad conduit is the power, the white romex goes off to the fixture. Yes the wires used as jumpers are the wrong color and it is daisy chained. In the second photo, the combo switch/power is the one on the top. The home has old cloth wiring which is disintegrating when manipulated, so I put (correctly colored to match original color) plastic sleeves on those wires coming out of the metal conduit which are shrunken into place with heat. I believe the romex must have been added later most likely when an electrician replaced the light fixture. Hope that helps? Is there a neutral?
Based on your info and the pictures provided, I don’t think you have a neutral.
A multimeter would show little to no voltage on the white wire if it’s a neutral.
If the outlets work, there must be a neutral. However it appears your panel is not providing a ground. While GFCIs are “legal” with just hot and neutral, I wouldn’t consider it “safe”. I am not an electrician, but seeing the load’s ground wired to all three outlets sure looks misleading and potentially unsafe as well — are you sure that’s the load? Nowadays I don’t think this box (is it even a box?) would be wired this way (speaking of which, if there isn’t one, strongly consider getting a box put in the wall, especially with 80+ year-old wiring in deteriorating paper).
At a minimum, get a no-contact voltage tester. Find the hot from the panel and confirm it dies when you open the breaker (I hope it’s the romex and you have a ground wire!). The non-hot line from the panel is the neutral. The other cable into the box is your load, one wire of which should only be hot when the switch is “on”. If you still want to do the work yourself, get an “old work” box and some wire nuts so you can eliminate the daisy chain. I’ll try to post a diagram when I have time later.
This is not an accurate statement. An outlet can easily work without a neutral.
In theory yes, you just need a voltage difference, such as between two hot phases. But assuming the receptacles are working with 110Vac in US residential, then one wire is almost certainly neutral. (Plus, if both lines were hot, what reference do you use to measure them with a multimeter, particularly when only two wires are provided from the panel?)
Agreed, the issue is the wiring is old and appears to be tapped for another source. There is a ground if you look closely, but without verifying the voltage per line I would not make assumption. Old wiring has as tendency to dead end and the neutral wire never makes back to the junction box.
When I see daisy chains with mismatched colored wires, I get very cautious with advice.
If the white wire is truly a neutral, the voltage will be close to nothing or zero if wired correctly.
If both lines are hot, call an electrician. I’d do that anyways. A service fee is no where near the cost of replacing an entire home.
@peterxian I owe you big time, thank you, so much looking forward to the rest of your answer (diagram)
Ignore this.
GFI will not work without a ground/earth wire. Yes, things plugged into the outlet will function, but there is no ground fault protection.A GFI detects current in the ground wire, thus the name Ground Fault Interrupter.
If you press the “test” button, does the interrupter snap open?
Even if the BMC conduit goes all the way back to the distribution (breaker) box, it can’t substitute the metallic conduit for the ground wire. The electrical code limits it to six feet.
So, you are painted into a corner here. Code requires GFI-protected outlets in wet environments, but you have no ground wire from the distribution box, so you can’t install the GFI in the bathroom.
You are really getting into “call an electrician” territory here. You need to replace the BMC with a 14/3 or 12/3 Romex (depends on the breaker size).
Looking at this, I can assure you that this was not installed by an electrician.
According to the OP, the ground wire in the photos goes to a downstream fixture. It is not connected to the ground at the distribution box. I.E., not connected to anything.
Why? You have no idea if that neutral wire is for sure connected to the breaker panel.
