I recently got a new wall sconce that uses non-dimmable CFLs. I have a regular 3 pole light switch downstairs that controls the light, and upstairs was a 3 pole dimmer switch. I have to take the dimmer switch out and put on a new regular 3 pole switch.
However, the wiring in the wall isn’t color coded the way the instructions on the three pole switch say they should be. The instructions want a black, white, red, and ground wire, I believe, where as I have two black wires, one red wire, and one ground.
What is the best way to tell which wire is the hot, which wire is the neutral, and which wire is the common?
"E"s answer good..i’ll add…none of the wires connected to the switches will be a neutral wire regardless of the color…..the neutral wire should be wire nutted in the switch box and pass directly to the load [ lights]…..i’m NOT an electrician but usually you take the hot wire coming into the switchbox upstairs and connect it it to the screw on the 3-pole switch that is "by itself" on the switch…then you connect the 2 screws that are on the opposite side of that switch to the 2 screws that are on the same side of the downstairs switch…then connect the wire that actually goes to the light [s] to the screw on the downstairs switch that is by itself on the side of the downstairs switch….another way of putting it :–if the 3 screws on the upstairs switch were labeled a,b,and c,,a being alone on its side,,b and c being on the other side…and the downstairs switch was the same,,,you would connect the hot wire coming into the upstairs switch to "a",,,then you would connect b from upstairs to b downstairs,,,connect c upstairs to c downstairs….finally the wire that goes to the light would be connected to "a" on the downstairs switch.. remember that the neutral wire never gets connected to the switch..it should be uninterrupted [ except for wire nuts] to the neutral connection at the light..the new switch likely has a diagram showing how to wire a 3-way circuit…….sorry if i’m too wordy,,dont explain this stuff very often……..dan
One of those wires (one of the blacks, if I was wiring it) will be your source for that switch. If you feel comfortable doing this, fan the wires apart and turn on the juice. With a hot stick or multimeter, determine which is your source – it will be the only wire carrying power. That wire gets connected to the black lug on the switch. The other two go to the brass lugs. Only do this if you have experience with and respect for electricity – otherwise call in the cavalry. Good luck!
I hope that you have not undone any twists or wraps in the wiring. If you have not, email me and I will give you the answer that you are looking for.
There is an industry-standard way of "making up" wiring in a switch box. This allows an electrician to come in and install the correct switch even though that electrician did not do the rough wiring. It is not likely that you will find this published in DIY books. It is not in the code books either. It is passed down from journeymen to apprentices.