3 Gang box & bundle of neutral

[methos]

I have a 3 gang box, 1 switch controls front porch lights.  The other two are 3 pole (stairs and foyer)
 
Bought a smart switch for porch lights.  opening the box, the single paddle switch had (2) blacks and no ground.
 
The SMART switch requires a neutral.  Looking into the BOX, there's a bundle of WHITE (assumed Neutral) crimp capped.  Can I use the NEUTRAL on this SMART switch and add it to this NEUTRAL bundle?   After marking the "hot" black wire, where does the "other" non power black line go?  This switch has a red wire, but I don't see where it's necessary ?
 
Thanks for reading this far!
 

 

[mikefamig]

 Regardless of the type of switch you will need to determine which of the wires in the house is "line", "nuetral" and "ground".
 
Yes you should use the bundle of white wires as the neutral to the switch.
 
The other two wires on teh switch connect to line and load. Line is the "hot" wire and load is the wire that goes to the lighting fixture.
 
Here is a simple diagram that may help
 
https://www.google.com/search?q=ac+light+switch+wiring&client=firefox-b-1&tbm=isch&source=iu&ictx=1&fir=cnpjOjP8Dlgt5M%253A%252CrFb4YzCYyaesCM%252C_&usg=__ieQS7l0IKPv355i9yRgQptvE88o%3D&sa=X&ved=0ahUKEwjXqISX1JbaAhXLxFkKHcgYDjgQ9QEILTAB#imgrc=cnpjOjP8Dlgt5M:
 
Mike.

 

[mikefamig]

You didn't say which smart switch you have but my Simply Automated UPB switch has a black, white and brown wire. Black connects to line voltage, white connects to white neutral and brown connects to the light fixture load.
 
Mike.

 

[mikefamig]

Here's a wiring diagram of an SA switch

 

[methos]

You didn't say which smart switch you have but my Simply Automated UPB switch has a black, white and brown wire. Black connects to line voltage, white connects to white neutral and brown connects to the light fixture load.
 
Mike.

Thanks Mike for the reply. Its the Eufy Smart Switch. Ive not seen crimp cas on the neutrals in this house before. The bundle of neutrals is rather large and thus far, unable to find ones of that size at the local box stores. Its already somewhat crowded in that box to add those mega wirenuts.

 

[pete_c]

Welcome to the Cocoontech forum methos.
 
Electric is electric is electric. 
 
There are no shortcuts.
 
Have a read here first:
 
How To: Replace a Light Switch
 
Basics have been mentioned above.
 
If you have any doubts about what you see or how to wire up an electric outlet or light switch I would personally call an electrician.
 
First and foremost when tinkering with your home electric is safety.
 
For the old fashioned analog light switch typically there are two wires; one being the line (black) and one being the load (goes to the lamp and can be black or some other color like red, blue or yellow). 
 
Many automated switches are little computers and need neutral and ground these days.
 
Personally never seen or read about the Eufy Smarth Switch.  Went to the website and they have no documentation posted for installation.
 
I looked on Amazon and there are pictures / reviews and really nothing about installation.
 
I did find a couple of pictures and drawings which show the switch to be wired to:
 
1 - neutral
2 - line
3 - load
4 - ground
 
Color defaults are typically
1 - white - neutral
2 - line - black
3 - load - can be yellow or blue or red or black depending on electrician - best way to check is at the light source wiring where you will see a white wire and another color going to the light bulb. 
4 - ground - green  - with metal conduit / pipes you can wire ground to box -
 
Romex I have seen and used is 3 wire plus ground wire (which is not covered).
 
Curious how many white wires are coming together there.  Typically one white wire (neutral) goes back to the fuse panel and many times the neutral wire to a lamp goes through a switch box and many times it goes right to the light box.
 
You mentioned 3 wall gang box with two 3 way switches.  A three way switch typically has two wires plus a traveler.
The three way switches each carry a load and line and traveler wire.  I have seen the traveler wire be different colors.
 

 
The bundle of neutrals is rather large and thus far, unable to find ones of that size at the local box stores. Its already somewhat crowded in that box to add those mega wirenuts.
 
Break the bundle down to two bundles with an interconnect white wire.   Typically the wire guage is 14.  Maybe use a 12 guage white wire to interconnect the bundles.

 

[mikefamig]

Thanks Mike for the reply. Its the Eufy Smart Switch. Ive not seen crimp cas on the neutrals in this house before. The bundle of neutrals is rather large and thus far, unable to find ones of that size at the local box stores. Its already somewhat crowded in that box to add those mega wirenuts.

 
Smart switches are larger than conventional switches sometimes just don't fit in the existing junction box. It's up to you to decide if you can safely fit the switch and wiring in there.
 
I don't like to twist more than three or four wires together. When I have a lot of wires to splice together I will make two separate splices and connect them to each other with a short length of wire.
 
As far as the wiring itself it would help if you could post the installation instructions here for us to look at.
 
Mike.

 

[JamesBabin]

You can't just grab any neutral wire to use for the switch. You have to use the neutral wire that corresponds with the netural for the lighting load. Crossing neutral wires between two different circuits is bad.
 
You might be able to easily identify that the neutral wire for the light load is in fact in that bundle just buy seeing how the romex is grouped, but if in doubt, remove the neutral wire that goes to the light and make sure it will no longer power on. If it still powers on you CANNOT use that neutral (even though it would work if you did).

 

[methos]

You can't just grab any neutral wire to use for the switch. You have to use the neutral wire that corresponds with the netural for the lighting load. Crossing neutral wires between two different circuits is bad.
 
You might be able to easily identify that the neutral wire for the light load is in fact in that bundle just buy seeing how the romex is grouped, but if in doubt, remove the neutral wire that goes to the light and make sure it will no longer power on. If it still powers on you CANNOT use that neutral (even though it would work if you did).

 
James - 
 
Good point.  The switch I'm replacing or attempting to only had (2) black wires.  No ground although there is one in the gang box.

 

[mikefamig]

methos
 
Be very careful to know that you understand the circuit before doing any wiring.
 
If there is just one circuit supplying power to that switch box and all of the white wires are spliced together then that is your one and only neutral for that circuit. The switches and bulbs are wired in parallel on that one circuit and I don't see how to distinguish one white wire from another. Each pair of black/white wires complete a loop/circuit to each lamp and return to the switch box where they are connected to each other in parallel and to the one power supply pair.
 
Am I misunderstanding something here? How can you segregate one white wire from the others when it is spliced together with all of the other white wires in the J-box?
 
Mike.

 

[JamesBabin]

methos
 
Be very careful to know that you understand the circuit before doing any wiring.
 
If there is just one circuit supplying power to that switch box and all of the white wires are spliced together then that is your one and only neutral for that circuit. The switches and bulbs are wired in parallel on that one circuit and I don't see how to distinguish one white wire from another. Each pair of black/white wires complete a loop/circuit to each lamp and return to the switch box where they are connected to each other in parallel and to the one power supply pair.
 
Am I misunderstanding something here? How can you segregate one white wire from the others when it is spliced together with all of the other white wires in the J-box?
 
Mike.

It's likely the neutral for the lighting, but I've lots of junk wiring that would leave a neutral from another circuit in that box. If it's an EMT install you could have the light fixture box piped between the feed and the switch, the neutral wire could stop in the fixutre j box and only the two line and load side of the switch are fed through the conduit to the switch box. Then, there may be an outlet circuit not connected to the lights and that's the spliced neutral.
 
Is it likely? No, but I've still seen it a dozen times. if its' a romex install (with two black wires it probably is), there's way less a chance of that happening. Anyway, my point was to verify the neutral before using it, takes 5 seconds.

 

[ano]

It's likely the neutral for the lighting, but I've lots of junk wiring that would leave a neutral from another circuit in that box. If it's an EMT install you could have the light fixture box piped between the feed and the switch, the neutral wire could stop in the fixutre j box and only the two line and load side of the switch are fed through the conduit to the switch box. Then, there may be an outlet circuit not connected to the lights and that's the spliced neutral.
 
Is it likely? No, but I've still seen it a dozen times. if its' a romex install (with two black wires it probably is), there's way less a chance of that happening. Anyway, my point was to verify the neutral before using it, takes 5 seconds.

I've seen it also.  I have no idea what they were thinking and how it was it was approved, but I've seen it. One switch in a box to one light with one breaker, and another to another light on another breaker. Its very dangerous too, because you think a breaker shuts off the power to the box, but it doesn't. If its allowed under the code, it shouldn't be.

 

[mikefamig]

Something to consider when looking at the wiring in that switch box is that there is a practice allowed by code that I've heard called "shared neutral". I don't know if it is NEC or local ordinance but the builder of my home used it.
 
This is when you have two line voltages on opposite phases sharing a single neutral path back to the load center. It is two circuits provided by three wires -  line-1, line-2 and neutral that commonly uses 1 black, 1 red and 1 white wire. You might think that this could potentially overload the neutral wire but it won't because the loads on line-1 are negative when the loads on line two are positive and the sum of the two never exceed the ampacity of either one circuit.
 
Here is a link that may help
 
https://diy.stackexchange.com/questions/12868/can-two-circuits-share-a-neutral
 
Mike.

 

[mikefamig]

another link re shared neutral circuit
 
http://www.ecmweb.com/content/code-quandaries-48

 

[cobra]

Note that for safety, all the discussions mention that those two lines must use a common breaker.  This is a safety issue, so that one line cannot be energized while the other is de-energized (and sharing the neutral.)