For many years NFPA 72, National Fire Alarm and Signaling Code, has required as a minimum that smoke alarms be installed inside every sleep room (even for existing homes) in addition to requiring them outside each sleeping area and on every level of the home. (Additional smoke alarms are required for larger homes.)
NFPA 72, the National Fire Alarm and Signaling Code, is a model standard used by electricians, architects, engineers, builders and inspectors to determine what features and equipment must be included in a fire alarm system. NFPA 72 applies to both residential and commercial buildings.
Although the electrical code doesn't require that hardwired smoke detectors be connected to their own dedicated circuit, it doesn't hurt to install a new circuit to power these detectors. Hardwired detectors are usually installed by splicing into a general lighting circuit or outlet circuit.
It must go to the PGM 2 terminal and not any other PGM terminal for 2-wire smoke detectors. You will then take the positive wire from your first smoke detector and wire it into the AUX+ terminal on the main board.
The maximum number of smoke alarms that should be interconnected per NFPA 72 standards is 12. Always make sure the smoke alarms you are interconnecting are compatible. In addition to the 12 smoke alarms in the series, you can connect up to 6 compatible devices like door closers, bells, or lights.
Essentially, any hardwired alarm installation that requires more than 12 smoke alarms needs to have a complete residential fire system installed.
Smoke or heat alarms shall not be interconnected in numbers that exceed the manufacturer's published instructions. In no case shall more than 18 initiating devices be interconnected (of which 12 can be smoke alarms) where the interconnecting means is not supervised.
Some traditional alarm systems panels are connected to 2-wire smoke detectors that are powered by a special smoke zone supplying supervised 12V power. 2-wire smoke detectors carry power and signal over the same pair of wires by using a special polarity reversing switch to indicate an alarm.
Absolutely! You can mix and match hardwired First Alert, BRK, and Onelink models. All of our current models use the same wiring harness and connector. We do not recommend mixing different brands since we can only guarantee the performance of First Alert and BRK alarms.
Tuck the orange wire inside the junction box. It is used for interconnect only.
Federal Code for Dwellings
Receptacles for permanent smoke detectors or alarm systems do not require GFCI protection.
The same fuse or circuit breaker in the home powers all interconnected units. The total length of wire interconnecting the units should be less than 1000 feet (300 meters), and the maximum number of interconnected units on the same circuit is 18 total units, with 12 of those being smoke detectors.
Fire alarm cable must have a voltage rating of at least 300V and (new with the 2017 NEC) a temperature rating of at least 60 DegrC [760.179(C)]. Type FPLP plenum cable must be listed as being suitable for use in a plenum space [760.179(D)]. Cables must be marked per Table760.
NFPA 72 requires that all points on the ceiling have a detector within a distance of 0.7 times the listed spacing of the detector. This ensures that when detection is used, the entire space on the ceiling is covered by detection. This requirement is commonly called the Point 7 (0.7) Rule.
907.2. 11.7Smoke detection system. Smoke detectors listed in accordance with UL 268 and provided as part of the building fire alarm system shall be an acceptable alternative to single- and multiple-station smoke alarms and shall comply with the following: 1.
Since no one can predict what type of fire might start in their home, the U.S. Fire Administration recommends that every home and place where people sleep have: Both ionization AND photoelectric smoke alarms, OR. Dual-sensor smoke alarms, which contain both ionization and photoelectric smoke sensors.
If your home was built after 1986, it will have at least one hard wired smoke alarm connected directly to your electrical panel. It is not acceptable to replace a hard wired alarm with one that is battery operated. A home must maintain at least the same level of protection as originally required.
The difference between these two types is the sensor that is used to detect the smoke. An ionization smoke alarm is generally more responsive to flaming fires (imagine a fire where you can see the flame), while a photoelectric smoke alarm is generally more responsive to smoking, smoldering fires (such as a cigarette).
The interconnected smoke detectors need to be on an dedicated 15amp arc fault breaker. This circuit shall serve nothing but the smoke detectors. The wire from the breaker to the first detector will be 14-2 with ground. Then from one detector to the other - you will use 14-3 with ground.
Either a 15-amp circuit (wired with 14-gauge wire) or a 20-amp circuit (wired with 12-gauge cable) is acceptable for powering hardwired smoke detectors. Wiring the smoke detectors is fairly straightforward for an experienced DIYer or a professional electrician.
2 Wire smoke detectors use the same wire pair to provide both power to the detector as well as carrying the signal back in case smoke is detected. The wires connect to the PGM terminals on your alarm system. 4 Wire Smoke Detectors 2 wires to provide power from the security system auxilliary output connections.
For many years NFPA 72, National Fire Alarm and Signaling Code, has required as a minimum that smoke alarms be installed inside every sleep room (even for existing homes) in addition to requiring them outside each sleeping area and on every level of the home. (Additional smoke alarms are required for larger homes.)
The electrician runs the red wire from alarm to alarm to interconnect them. When any alarm detects a fire, it sends a 9-volt signal on the red wire.
A smoke detector will provide coverage up to 100m² on a flat ceiling. However, a detector should not be more than 6m from any wall, or obstruction, and no more than 12m from another detector. It may be necessary to have additional detectors fitted, depending on the building's layout.