Switch Smarts: How to Safely Install Electrical Mechanisms
When it comes to installing or repairing electrical switches, outlets, and fixtures, first thing’s first—turn the power to the switch, outlet, or fixture you will be working on. To do so, you can either trip the circuit breaker or deactivate the fuse that powers the specific circuit in question. If you do not know which circuit breaker or fuse controls the particular circuit, trip your main breaker or remove the primary fuse; keep in mind that either of these actions will most likely turn off the power to your whole home.
Whether you are installing or repairing a switch fixture, it is helpful to have an understanding of the basic types of switches and their functions and configurations. Here are the three main types of switches:
This type of wall switch has an armature (moving part) that is shaped like an arrow. It floats between two points of contact when the switch is turned off. When the switch is turned on, the armature connects with both terminals to establish a constant flow of electricity to the appliance or light it powers.
Mercury wall switches have a small cylinder that is hollow and contains mercury. When this type of switch is turned off, the small point of contact is higher than the level of mercury. When a mercury switch is turned on, the point of contact becomes immersed in the mercury, which allows the flow of electricity.
This kind of switch uses a spring armature made of steel that is pushed off of the terminal when it is off. When you turn the switch on, the steel spring is pushed against the point of contact, establishing the flow of electricity through the circuit.
This switch system is the most basic type. It provides a way to break or feed an electrical current, whether to a light, an appliance, or another device. This kind of switch has two terminal screws made of brass. Typically, the black wire is cut and connected to both of the brass terminals. The white wire then remains an uninterrupted connection from the source of power to the light, appliance, fixture, etc.
Working outside the main wiring run
To install a regular toggle switch outside of the main run or wiring, first turn off any and all currents at the primary service panel. Connect the switch black wire to the light fixture black wire, and then connect the switch white wire to the power source black wire. Finally, attach the black wire to one of the terminals and attach the white wire to the other terminal. Keep in mind that green screws are for ground wires.
Connecting white and black wires
Whenever you have to connect a white wire to a black wire, it is essential to paint each end of the white wire black to signify that the white wire has been connected to a source of power. Attach the light fixture white wire to the power source white wire.