The common wire, also known as the “hot” wire, is typically connected to the black terminal on each switch. However, it is important to note that the color of the terminal may vary depending on the manufacturer or specific wiring system used. It is always recommended to consult the instructions or labeling provided with the switches for accurate identification.
In residential electrical wiring, the common wire carries the electrical current from the power source to the switch and then to the light fixture. It is crucial to properly connect this wire to ensure the switch functions correctly and the power flows smoothly to the desired destination.
To identify the common wire, you can follow these steps:
1. Turn off the power: Before working on any electrical connections, it is essential to turn off the power to the circuit by switching off the appropriate breaker in the electrical panel.
2. Examine the switch terminals: Remove the switch cover plate to access the switch. Each switch will have screw terminals where wires are connected. Typically, a standard switch will have two brass-colored terminals and one dark-colored terminal. The dark-colored terminal is the common terminal.
3. Check the wiring diagram: If the switch came with a wiring diagram, refer to it to confirm the location of the common terminal. The diagram will provide a visual representation of the switch and the corresponding terminals.
4. Test for continuity: If you are still unsure about which terminal is the common wire, you can use a multimeter set to continuity mode. With the power still off, touch one probe of the multimeter to the common terminal and the other probe to each of the other terminals. The common terminal should show continuity with only one of the other terminals.
5. Label the wires: Once you have identified the common terminal, label it with a piece of tape or marker to avoid confusion during reinstallation or future maintenance.
It is worth mentioning that in some cases, the common wire may be colored differently than black. While black is commonly used for hot wires, it is always recommended to verify the wire’s function using other methods, such as testing for continuity or consulting professional assistance if needed.
Remember, working with electrical wiring can be dangerous if you are not experienced or knowledgeable. If you are unsure or uncomfortable with any electrical work, it is best to seek the help of a licensed electrician to ensure the job is done safely and correctly.