How To Hard Wire Smoke Detectors

Smoke detectors have been invented to alert the tenants when there is smoke since there is a possibility of a fire. Many lives have been saved because of this. But if the smoke detector is not working, then lives are at risk. One reason for a smoke detector to be defective is that the battery has not been replaced. A smoke detector requires battery replacement after every few months. But sometimes owners of houses and buildings forget such things or some just do not care about the safety of their people. This is what makes hard wiring smoke detectors preferred by home owners. Furthermore, when one smoke detector alarms, all the smoke detectors will also sound the alarm. This way, the whole house will be alerted. Also, hard wired smoke detectors have battery backup. Initially, they run on electricity, but when the power goes out, the smoke detectors automatically run on battery.  With this, you can be sure that the smoke detectors will not fail to alarm in times of emergency, with or without electricity.

Here are steps on how to hard wire smoke detectors:

  1. Take not of the position of the smoke detectors. The smoke detectors should be placed in every level of the house or building, precisely outside each door, according to the National Electric Code. If you are setting up in walls, smoke detectors are commonly installed one foot below the ceiling. With the help of stud finder, find the studs to prevent the smoke detector from ending up on a stud. Position the cut-in box against the wall or the ceiling if you like, and mark the outside of the box with a pencil. If you are planning to place it in the ceiling find the ceiling joists and cut adjacent to them as these can provide you a good box support. When the marking is done, start cutting holes in the wall with a drywall saw.
  2. Connect wires from the fuse box or electric panel to smoke detectors. From the panel, extend a 12-2 NMB with ground wire towards the first box. Then from the first box, extend a 12-3 NMB wire with ground wire to the second box. In case there are more boxes, extend a 12-3 NMB with ground wire to all boxes. When you are done, make sure you only have two wires in each box.
  3. Tie together the 2 black wires from the first box, including the black wire coming from the connection of the smoke detector. Connect all white wires. Connect  the bare copper ground wires to each other and make a pigtail connection to attach it unto the box. Attach the red wire unto the smoke detector’s interconnected wire. Use wire nut in making connections. Wire nut must be able to wrap uncovered wires.
  4. Put the smoke detector mounting bracket on the opening of the box. The wire connection must pass through the bracket’s center hole. Align the screw holes and screw the mounting bracket tightly.
  5. Insert the plug (the one you finished wiring) in the back of the smoke detector. Place the detector on the bracket.
  6. Now make the connections in the electrical panel. Once the circuit is on, you will notice the “ready” sign on the detector lights up. Push the test button. After testing and everything is fine, you can pop in the backup battery and you are ready to go.

Backup batteries of hard wired smoke detectors must be changed once every year, while the smoke detectors themselves must be replaced every decade even though these are not defective.


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