I a want to change out a pole switch to a timer switch. All makes sense except, there are only two wires on the pole switch and 4 on the new switch. So I only have the white and black and no ground available, but it's a metal box. And the switch also has a red wire. What do i do with the ground and the red?
Electrical – How to change a single-pole switch to a timer with 4 wires
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I've annotated your image...
It's not possible from the image to tell which of the wires marked with red is the feeder from the breaker, and which is the feeder to other devices on the circuit. However, since you're simply replacing a switch with a timer, you'll not have to touch these wires anyway. The neutrals can also be ignored, unless you're installing a "smart" switch that requires a neutral wire.
Without knowing the exact make and model of the timer being installed, it's not possible to provide exact installation instructions. Instead I'll provide basic "typical" installation steps.
- Start by turning off the power to this circuit at the breaker/fuse box, and verifying the power is off using a non-contact voltage tester.
- Remove the two black wires from the switch you'll be replacing (One marked orange, and one marked blue in the image above).
- Throw the now disconnected switch haphazardly over your left shoulder.
- Connect a bare or green wire from the grounding screw in the box to the green screw or wire labeled
Groundon the device. - Connect the black wire coming from the twist-on wire connector (labeled orange in the image above) to the black screw or wire labeled
Commonon the device. - Connect the other black wire to the brass screw or wire labeled
Loadon the device. - (Optionally) If a neutral is required, follow steps 7a - 7c
a. Remove the twist-on wire connectors connecting the neutral wires.
b. Include a short bit of white wire in the bundle, and reinstall the twist-on wire connector (make sure the connector is rated for the proper number of conductors, a new twist-on wire connector may be required).
c. Connect the other end of the short bit of white wire to the silver screw or wire labeledNeutralon the device. - Restore power at the breaker/fuse box.
- Turn the fan on/off a few times and marvel at how awesome you are. YOU have harnessed ELECTRICITY!!!
Here's some wiring diagrams from various timers on the market...
I'm surprised that the box or paperwork that came with the switch didn't have instructions, so here is my advice (25 years as an electrician): The black wire goes to the hot bundle, the green wire is ground, and the blue wire goes to the light that is being switched. If there is a pig-tail that acted as an individual wire to the old switch, you can either keep that and attach the black wire to it, or remove it from the bundle and connect the black wire on the switch directly to the bundle.
As a way of checking what I am telling you, on the switch itself, there may be some labels for each of the wires (the black, blue and green wires). Typical labeling for the 'hot' wire is: "Hot", "Common", and "Line" Typical labeling for the switched wire is: "Load", "Line", or "Switched"
Note that in my experience, whenever the label for the Hot wire is "Line", the switched wire is never called "Line" -it is almost always labeled "Load" (which is more accurate -but let's not argue semantics).
Good luck and happy wiring!
:) Greg
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Best Answer
You should read the instructions included with the new switch. You'll likely find that the black wire is an ungrounded (hot) wire, the white is a grounded (neutral), and the red is the switched "hot" wire.
If there are only two wires coming into the box, you won't be able to connect the timer. The timer requires a grounded (neutral) connection, which is not present in a typical switch loop.
As for the ground wire. If the metal box is grounded, you can connect the ground from the switch to the box. You can connect the ground using a ground screw and the threaded hole in the back of the box, or using a ground clip.