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Help Wiring a Switch with 2 black wires and one white

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[OP]
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May 22, 2012
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Toronto

Help Wiring a Switch with 2 black wires and one white

Hi, can some one help out with this switch. We bought an older home and I’m trying to replace this switch with a TP-link Kasa switch (HS200), but when I opened I see there three wires going to the switch, 2 blacks and two whites...
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I’ve never seen a white wire connected to a dumb switch before, is it possible to add a Kasa switch to this? The switch controls our porch lights, and it’s not a 3way, only this switch controls it. The porch lights have dusk to dawn sensors built into them, if that makes a difference, but we only want them to stay on till about midnight.
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Any help will be greatly appreciated, thank you!
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platinumtiger19 wrote: Hi, can some one help out with this switch. We bought an older home and I’m trying to replace this switch with a TP-link Kasa switch (HS200), but when I opened I see there three wires going to the switch, 2 blacks and two whites...

F111BE24-5FE5-4534-BEDA-3B02F8CBC9D2.jpeg4125D611-5923-459D-A1ED-5ED821424E2B.jpegDB60B37C-E0D6-496E-BAE4-3CFB029B914D.jpeg

I’ve never seen a white wire connected to a dumb switch before, is it possible to add a Kasa switch to this? The switch controls our porch lights, and it’s not a 3way, only this switch controls it. The porch lights have dusk to dawn sensors built into them, if that makes a difference, but we only want them to stay on till about midnight.

75D906AC-8261-4D24-9ECA-C03F6333503B.jpeg

Any help will be greatly appreciated, thank you!
I have the same outdoor light fixture ... it's on a WIFI switch that the electrician swapped for me when they did the potlights inside.
16'x11' Living Room 11' Cathedral Ceiling. Hisense 65Q8G. Denon AVR-S740H 7.2 setup. Jamo Classic 10 280W Towers - FR+FL; Polk S35 - Center; Klipsch R51M - RR+RL; Klipsch R14M - Dolby FHR+FHL; Polk HTS10 Subwoofer x2. Unlocked Android Boxes from Taiwan x2
[OP]
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May 22, 2012
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Toronto
Thanks, I did read those threads but they don’t really help. I have a white wire(which I thought was always neutral) connected to the switch along with two black wires. And the switch is not a 3way
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Jun 26, 2019
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GTA
platinumtiger19 wrote: Thanks, I did read those threads but they don’t really help. I have a white wire(which I thought was always neutral) connected to the switch along with two black wires. And the switch is not a 3way
Step 1: Ignore colors for the most part. Yes, some blacks will be hot and some whites will be neutral, but this is likely not the case for all wires here.

Step 2: Figure out what is what. For example, the white wire bunch in the marrette that are not connected to the switches are likely the neutrals, whereas the white wire connected to the switch is likely not.

Step 3: Plan out how to wire this based on your new product. I.E. restore how everything is connected right now to not screw stuff up, and most likely connect your smart switch to the neutrals. It looks like you have a lot of stuff passing through this box, so need to keep track of all that. If you can determine all the hot wires and all the neutrals, you can likely bunch them all (in the proper sized marrette), then wire the switches. Also, opening up the box outside will also help you see whats going on.

Aside, this looks like a busy box to start with. It's hard to tell the box depth, but, one thing I will say, and this could be very important, is that TP Link Kasa switches are fat AF. If the box is only of normal depth, with this much action going on in there, you're really going to have to cram everything in there. So you need to make sure everything fits and everything is secure, because I think some cramming will be involved.
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Before you can continue, you really need to identify the purpose of each wire.

A switch with 3 contacts, that is not a 3 way is confusing. Is there any possibility that it is a 3 way and the second switch is in a hidden corner of the garage for example?

Does this switch have a pilot indicator that shows when the switch is on?
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Jan 12, 2014
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I don't see a ground , doesn't the TP-link Kasa need a dedicated ground from the fuse box

also read this

"One of the two non-hot black wires is the light feed and the other is a feed to other loads - possibly some receptacles, but it doesn't matter.

With the power off, connect the black hot wire to the old switch. Connect either of the other two black wires to the other screw on the switch. Turn the power back on and turn the switch on. The light will either turn on or it won't.

If the light turns on, the second black wire you connected to the switch is the switch feed and the unconnected black wire is the feed to the other loads. If the light doesn't turn on, then it's the other way around: the connected wire feeds the other loads and the disconnected wire is the light feed.

Turn the power off and mark the wires before you disconnect them. Terminate the light feed to one of the two screws on the new switch. Do not use backstabs, even if the new switch has them. Splice the hot wire, the feed for the other loads and a short black pigtail together. Trim and cap the splice. Connect the pigtail to the other screw on the new switch."
"

https://www.doityourself.com/forum/elec ... wires.html
[OP]
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May 22, 2012
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Rick007 wrote: Before you can continue, you really need to identify the purpose of each wire.

A switch with 3 contacts, that is not a 3 way is confusing. Is there any possibility that it is a 3 way and the second switch is in a hidden corner of the garage for example?

Does this switch have a pilot indicator that shows when the switch is on?
No, no indicator. I’m going to search the garage to see if there’s a switch or something.
2Riskit wrote: I don't see a ground , doesn't the TP-link Kasa need a dedicated ground from the fuse box
All the grounds are joined at the back of the box
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platinumtiger19 wrote:
All the grounds are joined at the back of the box
where does this ground wire from the box terminated to

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2Riskit wrote: where does this ground wire from the box terminated to
I would assume that it would be grounded back to the panel. As long as you have the Romex grounded in the back of the box.
Penalty Box
Jun 24, 2015
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it could be a "double pole" switch, where think of it as 2 light switch circuits, but controlled by one toggle switch button. i never seen one personally but have read about them. this is the only thing i can think of with the 4 sets of wires , 2 wires could be for one circuit, the other 2 wires is another circuit? u need a volt tester to test the volts to see for sure
Hi
Penalty Box
Jun 24, 2015
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id like to take a closer look at this possible "double pole switch" ive never seen one but heard about it/

and those toggle switches look different, i remember seeing them at my buddys house in the west end. not sure who makes em
Hi
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May 22, 2012
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GoodFellaz wrote: it could be a "double pole" switch, where think of it as 2 light switch circuits, but controlled by one toggle switch button. i never seen one personally but have read about them. this is the only thing i can think of with the 4 sets of wires , 2 wires could be for one circuit, the other 2 wires is another circuit? u need a volt tester to test the volts to see for sure
This sounds like its outside my skill set. And as others have mentioned it might be a tight fit for a smart switch anyway, I'm just going to put it back and look for motion activated porch lights
GoodFellaz wrote: id like to take a closer look at this possible "double pole switch" ive never seen one but heard about it/

and those toggle switches look different, i remember seeing them at my buddys house in the west end. not sure who makes em
Its an old bungalow in the east end near UTSC. About half the switches look like this
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I would assume that any switch with 3 contacts is a "single pole, double throw" switch ( or SPDT for short). A diagram of a SPDT switch is below.

But rather than assume, you could remove the 3 wires and use an ohmmeter to confirm that your switch behaves like a SPDT switch. If you look at the switch closely you may find some designations stamped into the plastic near the screws which might be helpful.

A so called 3-way light switch is actually a SPDT switch internally.

With regards to fitting a smart switch into the box, I have found that most smart switches or electronic timers, have break-off metal tabs than can be removed to reduce the width of the switch.


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