How to Connect Smoke Alarms

According to the NFPA, more than 1/3 of all the homes in America are not protected by smoke detectors.

Smoke detector and wiring moduleSmoke detector and wiring module
Even more startling is the fact that the death rate in homes without working smoke detectors is 45 percent higher than in homes where they do work. In order to protect your family from becoming victims of a home fire, you must have working smoke detectors installed in your home. In the U. S. , one person dies in a fire every 156 minutes. The best type of smoke detector to use is the kind powered by electricity. These types can be connected in a series so if one goes off, they all do.

Run a 15-amp dedicated circuit from the electrical panel to the site of the first smoke detector. Then run a length of three-wire cable (black, red and white) from the first smoke detector's location to the second, from the second to the third and so on.

Pull the two lengths of wire into the old-work drywall box where the first smoke detector will be located. Install the box in the ceiling. Cut away the excess wire, leaving about 6 inches of each hanging outside of the box.

Strip away the outer sheath of insulation on both sets of wire to reveal the individual strands of wire. Then use the wire strippers to remove about 3/4 inch of insulation from each wire.

Take the wiring module from the first smoke detector and connect the two black wires in the junction box to the black wire on the wiring module. Follow the same procedure for the white wires. Then connect the red wire in the junction box to the yellow (or red) wire on the wiring module.

Install the smoke detector as recommended by the manufacturer.

The wiring for each smoke detector after the first one will be the same--black wires connected together, white wires connected together and the yellow (or red) module wire connected to the red wires.

Upon completion, turn the circuit on and insert a new backup battery in each smoke detector.

Press the "Test" button on one of the smoke detectors and, if wired properly, they should all ring.

Things You Will Need

  • Dedicated circuit for the smoke detectors
  • One smoke detector for every floor in the home
  • Wire strippers
  • Wire connectors
  • Electrical tape
  • Old-work drywall boxes

About the Author

Based in Atco, NJ, Dave Donovan has been a full-time writer for over five years. His articles are featured on hundreds of websites, and have landed him in two nationally published books "If I Had a Hammer: More Than 100 Easy Fixes and Weekend Projects" by Andrea Ridout and "How to Cheat at Home Repair" by Jeff Brendenberg.