How to Reconnect Interconnected Smoke Alarms

Trip the circuit breaker at the fuse box to discontinue electric power to the area where the defective smoke alarm was located. Place a ladder beneath the hole where the smoke alarm was mounted to the ceiling.

Place the replacement smoke alarm face-up on a table. Twist the top off using a counterclockwise motion. Insert the battery backup into the battery compartment and twist the top back on using a clockwise motion.

Turn the replacement smoke alarm over. Strip a one-half inch of insulation off the ends of the wires attached to the back with a wire stripper; if there are no wires attached to the back, strip the insulation from the wire connector tab instead and then insert the tab into the corresponding socket on the bottom of the alarm.

Pull the wires out from inside the hole in the ceiling. Twist the end of the "hot" black wire from the hole around the end of the black wire from the alarm. Twist the end of the "neutral" white wire from the hole around the white wire from the alarm.

Twist the end of the "ground" copper-colored wire from the hole around the end of the copper-colored wire from the alarm; if there is no copper-colored wire in the hole, loosen the screw at the corner of the electrical junction box that is inside the hole with a Phillips screwdriver, wind the end of the copper-colored wire from the alarm around the screw and tighten the screw.

Twist the end of the red interconnecting wire from the hole around the end of the yellow wire from the alarm.

Twist an electrical nut onto each pair of twisted wires. Stop screwing the nut on the wires when the resistance is too great to continue.

Push the wires into the hole. Place the back of the replacement smoke alarm against the mounting plate that was left on the ceiling. Twist the alarm onto the plate with a clockwise motion.

Place the ladder away and restore the electric power at the fuse box.