How to Connect a 120 Volt AC Smoke Alarm to an Alarm System

Most hard-wired smoke detectors can be wired individually as stand-alone units, but a more efficient and safer method is to have a detector in all rooms except the kitchen and bathrooms. Wire the detectors together in a system so if one sounds the alarm they all will. By using this system potential victims are more likely to be awakened by the alarm and escape a fire.

Circular non-metallic ceiling box self mounting for each smoke detector
Carpenter's pencil
Drywall saw
NM 14/2 wire
Diagonal wire cutters
Wire strippers
NM 14/3 wire
Screwdriver
Wire nuts
15-amp breaker

Instructions

- 1
  Mark where the smoke detectors are to be located by tracing the face of the self-mounting non-metallic circular ceiling box with your carpenter's pencil. Cut all the holes for the ceiling boxes with a drywall saw. Route a NM 14/2 wire from the breaker box to the first hole. Cut the wire with the wire cutters leaving about eight inches hanging from the hole. Cut the outer sheathing over the wires to the back of the box. Strip the insulation off the individual wires 5/8 inch.
- 2
  Run another wire, NM 14/3, from the first hole to the second leaving eight inches hanging. Run another wire, NM 14/3, from the second box to the third. Repeat this process to all the holes.
- 3
  Install the ceiling boxes by sliding the wires into the openings in the box for the wires, and push the box in the hole in the ceiling. The lips on the face of the box will keep the box from going into the ceiling. Tighten the two screws on the sides of the front of the box. Those screws will turn two flaps out behind the drywall to secure the box.
- 4
  Connect the terminal plug for the smoke detector to the wires in the first ceiling box. Twist the black wires in the box with the black wire to the plug and twist on a wire nut. This is the hot wire that powers the detector and sends power down the line to the other detectors. Twist the white neutral wires in the same manner. Connect the yellow wire from the plug to the red wire in the box. This is the interconnecting wire that will bring on the alarm on all the detectors. Twist all the ground wires together.
- 5
  Take the mounting plate off of the detector by giving it a slight clockwise twist. Pull the plug through the hole in the mounting plate, and match the slots on the plate with the mounting screws on the box. Slide the slots over the screws and tighten them. Open the cover of the battery compartment and remove the seal over the terminals of the battery.Close the battery compartment, plug the smoke detector in and secure the detector to the base with a counterclockwise twist. Repeat this procedure with each of the smoke detectors.
- 6
  Turn the main breaker off. Remove the screws holding the cover on and lift it off. Install the 15-amp breaker according to manufacturers directions, as there are several mounting methods. Insert the black wire into the terminal on the bottom of the breaker and screw tightly. Screw the white wire into the neutral block, and the bare or green wire to the ground block. These blocks might be the same.
- 7
  Place the cover back on the electric panel, and tighten the screws. Turn both the 15-amp breaker and the main breaker on. Push the test button on each of the smoke detectors. All of the alarms should sound each time a detector is tested.

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