How to Make Screw Terminal Connections on Switches and Outlets

When connecting electrical wires to electrical switches and receptacles, there are two ways to do it, but only one is recommended by professionals. 

On the back of the body of the switch or receptacle, you will see slide-in connection holes that can allow you to simply push the end of the bare wire to make the wire connections. While this might seem like a very convenient way to do it, virtually no professional electrician and few experienced DIYers ever use these push-in fittings—mostly because they've had experience with these connections coming loose.

While still allowed by Underwriters Laboratories (UL), these push-in connections are not very secure and often loosen over time. Loose push-in fittings can cause arcing, pitting of the surface area around the connection, sparking, and a buildup of heat. If you must use these push-in connections, always test the wires by tugging on them to make sure you indeed have a tight connection. It's better, though, to avoid them altogether in favor of using more secure screw terminal connections.  

Each switch and receptacle device has standard screw terminals on the sides of the device body. These are the connection terminals that are best to use, as there is little doubt that the connections are true when you complete your project. This article looks at the proper technique for using these screw terminals.