convert 4 wire to a 3 wire switch

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DavidW
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convert 4 wire to a 3 wire switch

Post by DavidW » Thu Jun 14, 2018 8:31 pm

I bought a digital timer switch for my front door light but it comes with 3 wires whereas my wall wiring has 4 wires. Can I cap the one that is not used or do I need to get one with 4 wires?

There is no 2nd switch and it is just on/off for the porch light....

thanks...

telecaster
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Re: convert 4 wire to a 3 wire switch

Post by telecaster » Thu Jun 14, 2018 8:33 pm

What was in the box before, and how were the four wires connected previously? Is there another switch that controls the lights in addition to the one you are replacing?

Parthenon
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Re: convert 4 wire to a 3 wire switch

Post by Parthenon » Thu Jun 14, 2018 11:43 pm

A four wire switch is usually found between two three wire switches which means there are three switches controlling the same light. If that is the case you'll need to do some additional digging to find out what is going on.

Ed
"What am I gonna do if I run out of money?"

inbox788
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Re: convert 4 wire to a 3 wire switch

Post by inbox788 » Fri Jun 15, 2018 2:08 am

You're rewiring the switch? How was the switch wired before? Is it just one switch and one light? No other switches or lights?

What color are the wires coming out of the wall? Why are there only 4 wires? (there could be as many as 6 wires with ground in/out)
Image

Check the wiring at the switch. Do you have any test equipment? (volt meter? non-contact tester?)

If in doubt, get qualified help.

tev9876
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Re: convert 4 wire to a 3 wire switch

Post by tev9876 » Fri Jun 15, 2018 7:52 am

My guess is that your switch is wired per the picture above. The black wires are the Hot that carries electricity from the breaker. The switch simply opens and closes this connection. The white Neutral wire is the return to the panel and does not need to be opened/closed to turn the circuit off/on. If it was actually wired to multiple switches you would have a red wire in there also.

Electronic switches require a little bit of power to run their internal computer. This means they require the White neutral wire to complete the circuit. You would simply remove the two black wires from the existing switch and move them to the appropriate terminals on the new switch. You will likely need to know which is the panel (line) side and which is the load side - since the new switch always needs power the line side needs to be connected to the proper terminal so it always has power. Move the ground wire over also. You then need a short piece of white wire to connect from the new switch to the wire nut that is currently connecting the two neutrals.

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Kenkat
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Re: convert 4 wire to a 3 wire switch

Post by Kenkat » Fri Jun 15, 2018 8:09 am

Depending on the manufacturer, there might also be an 800 number you can call for help. I have used Leviton switches in the past and they were very helpful in installation of dimmers into a circuit with three separate switches.

The Wizard
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Re: convert 4 wire to a 3 wire switch

Post by The Wizard » Fri Jun 15, 2018 9:03 am

Helpful replies so far, but a key point is: the solution to this problem would be rather easy to figure out for anyone with a modest amount of experience with home wiring.

If the OP doesn't have experience with this sort of thing, the safest solution is to involve someone who does. A licensed electrician isn't really needed; a friend or neighbor might be able to help...
Attempted new signature...

wilked
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Re: convert 4 wire to a 3 wire switch

Post by wilked » Fri Jun 15, 2018 9:24 am

Post a photo t existing wiring and link to new switch

sixty40
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Re: convert 4 wire to a 3 wire switch

Post by sixty40 » Sat Jun 16, 2018 10:23 am

Having some experience in this field, be careful. Do not assume wire insulation colors are what they should be, always check with a voltmeter to confirm. If you do not know how to use a volt meter, it may be best to ask for help. In general white is neutral, green or non insulated is ground, and the other colors including black and red are hot.

4-wires for a standard toggle switch is odd, unless like someone else stated it is the middle of 3-way switching.

Housedoc
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Re: convert 4 wire to a 3 wire switch

Post by Housedoc » Sat Jun 16, 2018 2:08 pm

Is it possible that of the 4 wires, 2 of them are connected together via wire nuts or around a screw lug on the switch? This would normally be the 120volt hot feed from breaker box. The hot wire would continue to feed another switch or outlet in the house.

inbox788
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Re: convert 4 wire to a 3 wire switch

Post by inbox788 » Sat Jun 16, 2018 6:01 pm

Are 4 wires coming out of the box or 4 wires bundled and wrapped inside an insulator layer?

The Wizard
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Re: convert 4 wire to a 3 wire switch

Post by The Wizard » Sat Jun 16, 2018 7:31 pm

Since the OP has yet to return, speculation on this problem is futile...
Attempted new signature...

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dratkinson
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Re: convert 4 wire to a 3 wire switch

Post by dratkinson » Sat Jun 16, 2018 8:14 pm

Could return the switch and install a solar module on the porch light.

Options to automate the porch light and bypass the switch rewiring issue.
--Install a screw-in solar module inside the porch light.
--Install a post lamp solar controller in a spacer box that moves the porch light ~1 inch from the wall.

In both cases, would want a solar module that has an override function so the light could be commanded on during daylight hours---emergency services often ask that a porch light be turned on so they can more quickly find a house.
d.r.a, not dr.a. | I'm a novice investor, you are forewarned.

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Sandtrap
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Re: convert 4 wire to a 3 wire switch

Post by Sandtrap » Sat Jun 16, 2018 8:15 pm

The Wizard wrote:
Sat Jun 16, 2018 7:31 pm
Since the OP has yet to return, speculation on this problem is futile...
+1
Agreed.

inbox788
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Re: convert 4 wire to a 3 wire switch

Post by inbox788 » Sun Jun 17, 2018 12:42 pm

The Wizard wrote:
Sat Jun 16, 2018 7:31 pm
Since the OP has yet to return, speculation on this problem is futile...
I hope he's OK...

Lots of "shocking" stuff: https://www.google.com/search?q=electri ... =isch&sa=X

This one was most appropriate one that gave me the best laugh[warning, profanity]: https://i.pinimg.com/736x/ee/a4/1c/eea4 ... b16fae.jpg

DavidW
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Re: convert 4 wire to a 3 wire switch

Post by DavidW » Sun Jun 17, 2018 1:58 pm

OP here

Sorry for the late reply. Got tied up with on other things.

I read your replies and got a bit overwhelmed....

I am not good at electrical and has hacked my way through over the years on minor projects. It is amazing that my house hasn't burned down yet :)

I think I will leave this one alone until I have get my friend (an electrician) to help me out.

Thanks....

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