How to Install a Wired Smoke Alarm

Go to the fuse box and pull the appropriate fuse/trip the circuit breaker that will stop the flow of electrical current to the room where the detector is to be mounted. Place a ladder beneath an existing light fixture in the room. Remove the screws from around the fixture. Pull the fixture off the ceiling. Pull the wiring out from inside the hole in the ceiling that the fixture covered.

Unscrew the insulation nuts from off the twisted pair of wires. Unwind the wires from each other. Place the lighting fixture aside. Unscrew the cover plate surrounding the hole in the ceiling, if there is one, using a Phillips screwdriver. Place the cover plate aside.

Place the smoke detector's cover plate on the ceiling in place of the cover plate -- pull the wires from the hole through the center hole in the plate first. Screw the cover plate to the ceiling using wood screws with a Phillips screwdriver.

Twist the top off the smoke detector and insert a back-up battery in the battery compartment -- in some cases a slide out tray in the side of the detector will hold the battery instead. Twist the top back on.

Wind the ends of the wires attached to the bottom of the smoke detector around the ends of the wires coming out of the hole in the following manner: the white wires together; the black wires together; the red wire from the detector around the end of the remaining wire from the hole. Twist an insulation nut over each of the pairs of twisted wires.

Push the wires into the hole. Place the bottom of the smoke detector against the cover plate. Twist the detector onto the cover plate with a clockwise motion -- in some cases the detector will be screwed to the cover plate instead with metal screws provided with the detector. Restore power at the fuse box.