How to Wire Multiple Lights With Three-Way Switches
- 1). Locate an available 15-amp circuit breaker that is not being used. Power off the circuit prior to working with the wiring and mark the circuit box to inform others of work being done to avoid having someone else energize the circuit. Check the circuit with a voltmeter or multimeter using the AC voltage setting to ensure there is no power.
- 2). Run a length of 2 conductor plus ground electrical cable (Romex 14/2) from the circuit breaker box to the first switch box. Cut the cable using the wire cutters, leaving about three feet of excess cable at the circuit breaker box and six inches of excess cable at the first switch box.
- 3). Run a length of 3 conductor plus ground electrical cable (Romex 14/3) between the first switch box and the second switch box. Cut the cable using the wire cutters and leave about six inches of excess cable at each box.
- 4). Run a length of 2 conductor plus ground electrical cable (Romex 14/2) from the second switch box to the first light fixture. Run a length of 2 conductor plus ground electrical cable (Romex 14/2) from the first light fixture to the second. Run a length of 2 conductor plus ground electrical cable (Romex 14/2) from the second light fixture to the next in series if more than two are being used. Cut the cable using the wire cutters and leave about six inches of excess cable at each box.
- 5). Strip the outer insulation from each of the cables that enter the switch boxes or light fixtures using the wire stripper. Remove the outer insulation to within an inch after the cables enter the boxes. Strip the outer insulation from the cable that enters the circuit breaker box back to an inch from where it enters the box.
- 6). Cut one additional six-inch length of 2 conductor plus ground electrical cable (Romex 14/2) for all but one of the switch boxes and light fixtures to be used for making pigtail connections from the main circuit to the boxes and fixtures. Strip the outer insulation completely off from these pigtails.
- 7). Attach one bare copper or green pigtail connector to the "Ground" (green) terminal of each of the switches and fixtures except for the last light fixture. Connect both of the bare copper or green ground conductors in each switch box or light fixture to the pigtail using a wire nut to make a three-way connection in all but the last light fixture. Connect the bare copper or green ground conductor in the last light fixture directly to the "Ground" (green) terminal on the fixture. Connect the bare copper or green conductor in the circuit breaker box to the grounding bar as indicated by other bare copper or green conductors connected to the same place. This will result in each fixture being connected to the bare copper or green ground wire that passes through each fixture.
- 8). Connect the white conductors in each of the switch boxes to each other using a wire nut so that the white conductor passes through the switch boxes without connecting to anything. Connect a white pigtail to the "Neutral" (lighter) terminal on all but the last light fixture. Connect the pigtail to both of the white conductors in all but the last light fixture using wire nuts. Connect the white conductor in the last light fixture directly to the "Neutral" (lighter) terminal on the light fixture.
- 9). Connect the black conductor in the last light fixture to the "Common" terminal (darker) on the light fixture. Connect a black pigtail conductor to the "Common" terminal (darker) on each of the other light fixtures and connect the pigtail together with both of the black conductors leading into each of the light fixtures except for the last light fixture. (Do not use this method for the switches, only for the light fixtures.)
- 10
Connect the black conductor from the 2 conductor plus ground electrical cable (Romex 14/2) leading into the first switch box to the "Common" (darker) terminal on the first three-way switch. Connect the black and the red conductors from the 3 conductor plus ground electrical cable (Romex 14/3) leading between the two switch boxes to the "Traveler" (natural brass) terminals in each box. It does not matter which color goes on which of the "Traveler" terminals as long as the red conductor connects to one and the black conductor connects to the other one. - 11
Connect the black conductor of the 2 conductor plus ground electrical cable (Romex 14/2) in the second switch box to the "Common" (darker) terminal on the second switch box. - 12
Connect the white conductor leading into the circuit breaker box directly to the neutral bar as indicated by other white neutral wires connecting into the same place. Connect the black conductor leading into the circuit breaker box directly to the 15-amp circuit breaker terminal. - 13
Install each fixture and switch into the respective boxes and provide power to the circuit. Test each switch and allow the lights to remain on for several minutes to ensure proper wiring.
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