Twin-Chime Doorbell Wiring

Select a junction box to accommodate the doorbell transformer; choose a box near the chime's installation location. Flip the box's circuit breaker to the off position; never perform electrical projects with the power on. Use a screwdriver to remove the box's faceplate. Tap and pull a knockout plate from the box's side with a screwdriver or needle-nose pliers.

Twist the mounting ring off the transformer. Insert the transformer's threaded shank through the knockout hole. Reattach the mounting ring to the transformer's threaded shank to secure the transformer to the side of the box. Join the transformer's wires to the box's existing wires with wire nuts. Wires are color-coded; black for hot, white for neutral and green for ground.

Separate the strands of a doorbell wire. Doorbell wire is typically 18 gauge and consists of two wires: one red and one white. Attach one doorbell wire to each of the transformer's terminal screws; the arrangement is arbitrary. Choose one wire, either red or white, to run from the transformer to the doorbell button.

Run the wire to the button and attach it to one of the button's terminal screws with a screwdriver. Run the remaining wire from the transformer to the terminal screw marked "T" on the twin-chime doorbell and attach the wire to the doorbell's terminal screw with a screwdriver.

Attach another doorbell wire to the remaining terminal on the button with a screwdriver and run it from the button to the open terminal on the twin-chime doorbell. Attach the remaining wire to the chime's open terminal with a screwdriver. Reattach the junction box's faceplate and turn the box's breaker to the on position. Push the chime's button to test the new installation.