Alarm boxes generally fall into two categories depending on their context: Public Emergency/Street Boxes and Building/System Initiating Boxes.
The two (2) life-safety alarms that can occur are fire alarms and carbon monoxide (CO) alarms. Fire alarms occur when there is an activated smoke detector or heat detector, while CO alarms occur when there is a triggered carbon monoxide sensor. These alarms are always audible to quickly alert building occupants.
A photoelectric smoke alarm uses photoelectric sensing technology, which is generally more sensitive than ionization sensing technology at detecting large particles, which tend to be produced in greater amounts by smoldering fires.
Ionization vs photoelectric
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). Let's dig deeper into the different types of smoke alarms.
There are four basic types of panels: coded panels, conventional panels, addressable panels, and multiplex systems.
What are the three main types of alarms? Fire alarms, burglary alarms, and intrusion detection systems are all types of alarm systems which have different functions.
Type 4 – Automatic fire alarm system activated by smoke detectors and manual call points. A Type 4 system comprises a Type 2 system plus smoke detectors with automatic signalling to a remote receiving centre.
The two main categories of fire alarm systems are Conventional and Addressable. They differ primarily in how field devices (like smoke detectors and pull stations) communicate with the control panel.
✅ IDCs connect initiating devices like detectors and pulls. ✅ NACs power notification appliances like horns and strobes. ✅ SLCs carry digital communication between the panel and addressable devices.
A fire alarm box, fire alarm call box, or fire alarm pull box is a device used for notifying a fire department of a fire or a fire alarm activation.
Cons of Ionization Smoke Detectors
Prone to False Alarms: Ionization detectors are notorious for their sensitivity. This can often lead to false alarms. Ionization detectors can also be triggered by cooking smoke or steam from the shower.
Ionization smoke detectors are being phased out by many retailers and safety experts. Because they are prone to false alarms from cooking, people often disable them. Furthermore, they perform poorly in detecting smoldering fires compared to photoelectric models.
Here are key indicators that it is time to replace your smoke detectors:
After putting more than 30 of the most popular home security systems through their paces, we narrowed the field down to the top eight. ADT earned the top spot thanks to its broad equipment lineup, dependable professional monitoring, and consistently fast alert responses. SimpliSafe and Vivint weren't far behind.
Ionization vs. Photoelectric most commonly refers to the two main sensing technologies used in residential and commercial smoke alarms.
Home fire alarms are categorized by their detection technology (Ionization, Photoelectric, or Dual-Sensor), power source (Battery or Hardwired), and smart capabilities. Fire safety experts recommend using a combination of both sensor types or a dual-sensor alarm to ensure rapid detection of both flaming and smoldering fires.
There doesn't seem to be a Code forbidding the two circuits together. If the NAC is for horns and strobes, running the NAC and the SLC for a short distance shouldn't be an issue. If the NAC is for speakers, the NAC shouldn't be run with any other circuit at all for any distance.
In electrical and life-safety systems, NAC stands for Notification Appliance Circuit. It is the specific circuit in a fire alarm system that connects the main control panel to emergency alert devices like horns, strobes, bells, chimes, and speakers.
Here are some common types of alarm systems:
L1: Maximum protection for all areas, including roof spaces and voids. L2: Coverage for escape routes and high-risk rooms. L3: Protection for escape routes and adjacent rooms. L4: Protection limited to escape routes.
Open circuits have no current flow when on standby but are less expensive to operate, while closed circuits are self-monitoring due to continuous current flow but use more power.
Alarm systems are broadly categorized by how they communicate and how they are monitored. The three main types are monitored (professionally watched 24/7), unmonitored (local siren-only), and smart/self-monitored (app-driven). They can run on wired or wireless networks and protect against intrusions, fires, or environmental hazards.
Thatcham Category 2 is an immobiliser-only category – alarms are not awarded this status. Just like Thatcham Category 1 systems, a Thatcham Category 2 device has to isolate at least two circuits or systems, or one vehicle control unit that's required for the car to run properly. Again, it has to be passively set.
Grade 3 intruder alarm systems - Medium risk
Grade 3 intruder alarm systems are intended to counter more experienced intruders who have advanced knowledge, tools, and equipment, including portable electronic devices. The system provides comprehensive protection for all possible entry points to a building.