This wire is sometimes red. One of the two non hot black wires is the light feed and the other is a feed to other loads possibly some receptacles but it doesnt matter.
Two Way Light Switching Light Fitting
Light switch wires all black. With the power off connect the black hot wire to the old switch. The last switch i came to was for an outside light. The black hot wire goes to the brass screw or into the hole in the back of the device on the same side as the brass screw. Two of the wires plugged into the back of the switch and the other attached to a side screw. All home electrical wires made in the us. It could be there is or once was a three way switch in play.
The hot wire in a 120 volt residential ac circuit usually is coated with black insulation while the return or neutral wire is white. Well cover the easier scenario first. Connect either of the other two black wires to the other screw on the switch. The green or bare copper ground wire if the device has one attaches to the green screw terminal on the switch or to the electrical box. Consider all black wires to be live at all times. Knowing which wire does what and goes where is imperative not only in the correct configuration of an electrical system but also for your familys safety.
In 220 volt circuits red wires are the secondary live wires. The easiest and safest way is to use a multimeter to test for current. A single pole single throw switch such as a light switch. When i removed the switch plate there were 3 black wires no white or ground. Like black wires they can also be used in some types of switch legs. However if you need to rewire a light switch or a plug socket you may occasionally come across two black wires.
When you see a red wire in a light switch box it can mean two things. Turn the power back on and turn the switch on. Also black wires are often used as switch legs in circuits which is the connection linking a switch to the electrical load. Or it could be the red wire is the wire going to the fixture and the black wires are the live wires. Its essential that you determine which black wire is hot before proceeding. Follow standard color codes that identify each wires function in a circuit.
I attached one wire to the top side screw on the new switch and the other two to the other side screw. Black means hot white signifies neutral and green indicates ground.
Gallery of Light Switch Wires All Black
