There are numerous benefits to adding fire alarms to an existing security system. Because they don't depend on batteries, they won't fail at critical moments. If your security system is connected to a larger monitoring service, they will be alerted in the event of a fire. Mounting a fire alarm to your home security system requires compatible two-wire smoke detectors which can be programmed to work with the existing devices. Provided you have that, it's simply a matter of connecting the proper wiring and ensuring that the alarms are on.
Things You'll Need
- Functioning Security System (with an accessible alarm panel)
- 2-wire Smoke detectors
- 2-conductor or 4-conductor Wiring
- Wire cutters
- 1 4.7K 1/8W Resistor
Determine the placement of your smoke detectors. Ideally, they should be mounted high up, but you may need to place them a little lower in order to link the wiring.
Run a length of 2-conductor or 4-conductor wiring from the alarm panel of your home security system to the location of the nearest smoke detector. Run the length from that detector the next closet detector. Continue in the same pattern with connecting it to the other closest detector until the wire reaches every spot you need. The wiring should form one long chain from the alarm panel to the furthest smoke detector. At leach location, provide 12 inches of slack in the wiring to let you work comfortably. Do not connect the wiring to the alarm panel yet.
Cut the wiring at each smoke detector location. Allow at least 6 inches of slack to work with. Strip the covering from the bundle. Then remove about 1/4-inch of insulation off the ends of the red and black wires. (4-conductor wiring will also have green and yellow wires that you can ignore.)
Connect the red wires into the negative (–) positions of the smoke detector's screw terminals and the black wires into the positive (+) positions of the screw terminals. There should be four positions on the terminals, allowing you to link each smoke detector to the one after it.
With the last smoke detector on the chain, attach the last red wire to the negative position on the terminal and the last black wire to the positive position on the terminal. Then secure an end-of-line 4.7K 1/8W resistor to the remaining two open positions on the terminal. This will properly secure the connection and prevent electrical accidents.
Mount the smoke detectors to their chosen spots. Do this using screws and a screwdriver. Most models will have simple housings which allow you to slide the screws into place. Some may use gang boxes or similar boxes. If that is the case, you can mount the box to the wall using screws the same way you would a stand-alone smoke detector. The detector itself can then be slipped into the pox and fitted into position.
Connect the 2-conductor wiring to the alarm panel: the black in the negative (–) SMK panel and the red in the positive (+) SMK panel.
Type in the activation code on the alarm panel corresponding to the circuit attached to the smoke alarms. Unlike the other circuits in the security system, you don't need to set a specific time to activate them. You simply need to turn the circuit on and ensure that power is flowing to the smoke alarms. You want them to function 24 hours a day, unlike security alarms which must be turned off during the daytime so that you can move an and out of protected doorways.