Wire Light Fixture Switch Loop

When the electrical source originates at a light fixture and is controlled from a remote location a switch loop is used.

Wire light fixture switch loop. At the receptacle the always hot wire is spliced to the black wire on the light fixture cable and to a pigtail that connects back to the hot terminal on the wall outlet. This circuit is wired with a 2 wire cable running from the light to the switch location. Next the incoming white neutral wire is attached to the light fixture as usual and the black wire from the switch is connected to the light fixture. Thread the light fixture s electric wires through the screw collar loop.

A standard single pole light switch will simply require you to attach the black load wire into it and then the black wire leaving the switch and to your lights. To make a switch loop connect the incoming hot black wire to the white neutral wire that runs to the switch. Mark the white wire at each end with black tape or black paint to indicate it is hot. The white or neutral wire bypasses the switch and goes straight to your lights.

The best way to do this is to make a pigtail which means to twist all the black wires going to fixtures together with a 6 inch length of spare black wire. Using a wire cutter cut the length of the light fixture s electric wires to the length of the house wires. The switch loop is a 3 wire cable to comply with nec requirements of a neutral in all new switch boxes. Connect the house wires and the wires of the new light fixture in the reverse way you used to disconnect the old light fixture.

In a switch loop situation both the wire that runs from the light fixture to the light switch and the wire that runs from the light switch back to the light fixture are hot or live wires. In home run light switch wiring each outgoing hot wire must be connected to the load terminal of the switch.