Can You Splice a Ground Wire for a Light Fixture?

Wiring Explained

• The wire used to create the circuit in a building is made of insulated copper (or, infrequently, aluminum). Electrical wire conducts electricity because the copper or aluminum material allows electrons to flow easily from one metal molecule to another when voltage is applied to the wire. Electrical wire is often made up of either three or four individual conductors that are placed inside an insulating sleeve. Each individual wire within that sleeve is insulated with a separate insulation jacket that is color coded to identify the function of the wire. A three-conductor electrical wire will often contain a black “hot” wire, a white “neutral” wire and a “ground” wire that is either insulated with a green jacket or contains no jacket at all. A four-conductor wire will additionally have a red or blue wire that is intended for use as a hot wire controlled by a switch.

Splices Explained

• An electrical wire can conduct electricity if the wire comes in contact with a voltage source or another wire that is energized. This property of electric wire allows electrical joints to be made by twisting together or soldering the ends of two wires. In a building, many of the electrical joints are mechanical connections that are made by twisting two or more bare wire ends together; this electrical joint is called a splice. The twisted wire joint is then insulated from the other wires and joints by twisting a wire nut onto the end of the joint.

Why a Ground Wire Is Present

• A ground wire is a safety measure for an electric circuit. A ground wire is used to carry electric current away from a light fixture or electrical device if there is an electrical fault. If a grounded device malfunctions, the electric current will flow through the ground wire to electrical ground. If the ground wire were not present, the electrical device or light fixture might remain energized due to the fault, and this fixture or device could pose a shock or fire hazard.

Ground Wires May Be Spliced

• If you plan to extend the circuit where a light fixture is connected, it will be necessary to splice each of the wires – including the ground wire – to create the circuit extension. The black wire in the light fixture junction box must be spliced with the black wire extending the circuit; likewise, the white wires must be spliced together, and the ground wires must be spliced to each other as well.