Installing Hardwired Smoke Detectors


Hardwired smoke detectors with battery backup are required in some places. They are wired in a series so when one alarm sounds, all sound. Running the cable is the hardest part of the job -- the time required depends on the layout of your home. In addition, you'll need to tie in to a single source of power.


About 5 hours to run cable and install three detectors

Voltage tester, drill, 1/2-inch bit, drywall saw, fish tape, screwdriver, strippers, long-nose pliers, lineman's pliers

Installing boxes; running cable into boxes; stripping, splicing, and connecting wires to terminals

Smoke detectors, boxes, 14/2 and 14/3 cable, electrician's tape, wire nuts

Step 1

For each detector, cut a hole for a standard 4-inch octagon or single-gang box. Run 14/2 cable to the first detector in the series and 14/3 cable to the others. Install the boxes.

Step 2

Align the slots of the mounting plate and attach the plate to the box. Gently pull the wires through the plate. After connecting the first box in the series, connect wires as shown.

Step 3

After securing the wire nuts with electrician's tape, gently push the wires into each box. Install the detectors, activate the backup batteries, and connect to the power source.

Comments (1)
Add your comment

You must be logged in to leave a comment. Register | Log In
Find a Pro

Get free quotes from prescreened professionals in your area.