replacing switch in 4 gang box - two black wires, which is the neutral?

[AcidWater]

I have to replace a light switch that's going bad, its in a 4 gang box. But the two wires connected to it are both black.
Which is the neutral for wiring the new switch?

Back in the 1980's I replaced the normal switch with an electronic switch that receives a wireless signal from a sensor,
which turns the light on when the sensor detects motion. Removed the sensor decades ago, but now the switch does not want to turn off the light, and its running hot. I cannot find the instructions for this product in any of the places where I file electrical system info.

The switch has a white wire connected to two black wires, which go to the switches on either side. The twist cap is red, with a piece of black electrical tape over it.
It has a black wire connected, with a white twist cap, to a black wire coming in from the back of the box.
The corresponding white wire from its romex cable is spliced to 3 other white wires, with a yellow twist cap.

The switches from left to right are the kitchen light, the bad switch to an outdoor light, another outdoor light, the back porch. I don't recall how many circuits are involved.

 

[Fitter30]

Switch does not have a neutral. Only a hot and a switch leg their is no place for a neutral. Neutrals usually stuffed back of the box wire nutted together.

 

[Sponsor]

 

[AcidWater]

Switch does not have a neutral. Only a hot and a switch leg their is no place for a neutral. Neutrals usually stuffed back of the box wire nutted together.

OK. But the question still remains - which of the wires in the box go on which terminal of the new switch? Does it not matter?

I know that black is hot, white is neutral, red is a sometimes hot traveller between two switches. But how several switches to different circuits are wired to the same fuse, with wire colors not as above, is beyond me.

 

[Reach4]

OK. But the question still remains - which of the wires in the box go on which terminal of the new switch? Does it not matter?

I know that black is hot, white is neutral, red is a sometimes hot traveller between two switches. But how several switches to different circuits are wired to the same fuse, with wire colors not as above, is beyond me.

Does not matter for that on-off switch.

 

[Afjes]

I know that black is hot, white is neutral, red is a sometimes hot traveller between two switches.

You have to keep in mind that not all white wires are neutral wires. This confuses many DIYers.
In the case of a switch loop.

Example:
You have a light switch for a single light in the ceiling. However instead of the power originating at the light switch box the power comes into the light fixture box. Take this case now. You have one hot wire, one neutral wire (let's forget about ground wires for now-they are just a given) coming into the light fixture box. Now you run a (for example) a 2 wire Romex down to the switch. At the light fixture box you connect the white wire of the new romex going to the switch to the incoming black hot wire from the power. Down at the light switch you connect the incoming white wire( which is now the hot wire feeding the switch) to either of the two terminal screws (this feeds the switch power), then you now connect the black wire at the switch to the other terminal and that other end connects to the light black wire at the fixture box. So what this is doing is taking the incoming power black wire at the fixture box, connecting it to the white wire going down to the switch, connecting to the switch and coming back up to the light to feed the power. Since power is coming into the light fixture box and no neutral is required at the switch (this type of switch) then you only have to feed power down to the switch and bring it back up again with the switch in the middle. When you look at the wiring in the light fixture box you will see in this case a white wire (being used as a hot wire) connected to the black hot wire coming in from power. When this is done; meaning using a white wire as a hot wire both ends of the white wire should have either a small pie3ce of tape wrapped around the wire at both ends or black marker indicating that the white wire in this case is being used as a hot wire. You may also see a white wire being used as a hot wire in a 3 way switching setup.

A standard single pole mechanical switch does not require a neutral wire.

 

[AcidWater]

Thanks, now I know I won't short anything out. But I need 6" of 14ga wire to make an extension in that crowded box, and all I have is 12ga. So off to Home Despot... $20 for 15 feet... Surprised with all the junk bits I have, there is NO 14ga !

Now you run a (for example) a 2 wire Romex down to the switch. At the light fixture box you connect the white wire of the new romex going to the switch to the incoming black hot wire from the power.

But why would I do that, and have to mark wrong colors, instead of connecting black to black and white to white:
source BLACK to BLACK traveller to SWITCH SCREW
source WHITE to WHITE traveller to SWITCH SCREW

 

[Reach4]

They prefer the always-hot wire to be the white, rather than having the white switched. A switched white is more likely to be confused with a neutral.

 

[Afjes]

he switches from left to right are the kitchen light, the bad switch to an outdoor light, another outdoor light, the back porch. I don't recall how many circuits are involved.

Are any of these switches 3 or 4 way switches or all single pole switches.
I ask this because then you say:

But why would I do that, and have to mark wrong colors, instead of connecting black to black and white to white:
source BLACK to BLACK traveller to SWITCH SCREW
source WHITE to WHITE traveller to SWITCH SCREW

If the switches are single pole switches there are no "travelers" involved.

Not all switch setups are always black to black, white to white, it depends on the circuit routing and type of switching circuit you are working with.

It is very common practice to have the power originate from the light fixture box down using a switch loop to the switch.

The white wire going down to the switch is "white"-"power" feeding the switch, the return wire at the switch going back up to the light is "black". There is no neutral going down to the switch since it is not required for a single pole switch. By code the wire going back up to the light needs to be black.

 

[LLigetfa]

The white wire going down to the switch is "white"-"power" feeding the switch

Is it customary/code to mark that white wire at the switch with a black magic marker or tape?

 

[AcidWater]

Are any of these switches 3 or 4 way switches or all single pole switches.
I ask this because then you say:

If the switches are single pole switches there are no "travelers" involved.

Not all switch setups are always black to black, white to white, it depends on the circuit routing and type of switching circuit you are working with.

It is very common practice to have the power originate from the light fixture box down using a switch loop to the switch.

The white wire going down to the switch is "white"-"power" feeding the switch, the return wire at the switch going back up to the light is "black". There is no neutral going down to the switch since it is not required for a single pole switch. By code the wire going back up to the light needs to be black.

Thanks much, got it straightened out. This window got lost in my browser dropdown menu...