How to Install a First Alert SA303 Smoke Detector

Go to the fuse box, which is typically on the wall in the basement or in a closet or out-of-the-way location. Open the fuse box cover and remove the fuse or trip the circuit breaker (depending upon the type of fuse box) that supplies power to the electric line where the First Alert smoke detector is going to be installed. Text on the inside of the fuse cover or beneath the fuses/circuit breakers in the fuse box typically provide the needed information as to which electric line would be affected by the fuse/circuit breaker.

Place a ladder next to the wall where the electrical junction box is located. Locate the metal of the junction box with a stud finder or from the blueprints of the home if they are on hand. Cut a hole in the wall where the needle on the stud finder twitched, using a utility knife. Shine a flashlight in the hole to confirm the presence of the box. Cut a square around the hole with the utility knife and pull it out of the wall. Enlarge the sides of the cutout until all sides of the electrical junction box can be seen. Pull the cutout from the wall.

Hold the First Alert smoke detector with the grill facing down. Rotate the mounting bracket on the top of the detector counterclockwise to remove it.

Place the mounting bracket against the electrical junction box. Screw metal screws through the slots in the bracket and into the screw holes in the box. Use a Phillips screwdriver.

Plug the power connector into the corresponding socket on the back of the smoke detector. Unscrew the screws on the electrical junction box that have a black, white and orange wire wrapped around them. Use the Phillips screwdriver.

Twist the black wires from the power connector and the electrical junction box together. Wrap the wires around the screw that the black wire was just removed from. Screw the screw in. Repeat this procedure with the white wires and the orange wires.

Place the back of the smoke detector against the bracket. Twist the smoke detector clockwise to secure it to the bracket.

Slide out the side-mounted battery tray. Place a 9 volt battery on the battery tray. Close the battery tray. Restore the power to the electric line.