Fire alarms play a critical role in buildings because they alert occupants when a fire is detected. Modern fire alarm systems can also notify the local fire department, allowing for an immediate response. They can also be set up to notify building managers and other key personnel when they are away from the building.

When building systems fail, the occupants are usually inconvenienced. An HVAC problem, for example, can make indoor temperatures uncomfortable. When fire protection measures fail, however, human lives and property are at risk. As a result, there is no room for error when designing and installing a fire alarm system. Proper maintenance is also necessary to ensure continuous protection.

Some fire protection measures may be optional depending on the type of building and local building codes. However, because of the protection they provide, building owners should consider installing fire alarms even if they are not required in a specific project.

Even if a building is never damaged by fire during its entire service life, fire alarms and other protection measures provide several advantages. When a building is well-protected against fire, for example, insurance companies may offer better plans and lower premiums. Reliable fire protection in buildings with commercial spaces for rent can help tenants sign a contract.

Heat or smoke detectors typically trigger fire alarms. They can, however, be activated manually or via flow sensors in fire sprinkler systems. There are two primary ways for a fire alarm to fail:

• Inadvertently activating when there is no fire, resulting in a false alarm.
• Not activating when there is a fire, which is far more dangerous.

A false alarm disrupts a building by causing an unnecessary evacuation and suspension of activities. Fire protection engineers recommend installing all other system components before the communication lines to avoid false alarms during installation. False alarms must be avoided at all costs because they can confuse occupants.

Not activating during a fire is a much more serious problem in alarm systems: it gives people less time to evacuate, and the fire department is not immediately notified. A faulty fire alarm system can also have legal ramifications, and insurance coverage may be revoked.

A fire alarm system must be both reliable and long-lasting. Consider that buildings can last for decades, and fire protection systems should be similarly long-lasting to reduce the need for repairs and part replacements.

Fire alarms are subject to stringent design standards because they serve an important function in buildings. While this adds to the complexity and cost of fire alarm systems, it is necessary to ensure that they always work properly.

The NFPA 72 National Fire Alarm and Signaling Code is the industry standard for fire alarms, and the NFPA 101 Life Safety Code includes design requirements. The National Fire Protection Association developed these standards, which also include design requirements for sprinkler systems (NFPA 13), as well as other fire protection measures and building systems.

• NFPA 72 addresses all aspects of fire alarm systems, including design, testing, maintenance, operation, and minimum performance standards.
• NFPA 101, on the other hand, addresses more general requirements, such as the occupancy groups in which fire alarms should be used.
• Because fire alarm systems contain many electrical components, they must also comply with the NFPA 70 National Electrical Code. Any non-compliant electrical installation, including fire alarm systems, creates a fire hazard.

Local governments reference NFPA standards when developing fire protection requirements for their building codes. Building owners with properties in multiple cities must be aware of code differences. It is critical to work with a qualified engineering firm to ensure that local requirements are met.

Fire alarm systems must meet NFPA standards as well as use components listed by Underwriters Laboratories (UL) or a similar certification laboratory. If the connections and devices of a fire alarm system themselves pose a fire risk, the system’s purpose is defeated.

Existing fire alarm systems do not always need to be upgraded when new fire protection codes are published. If a particular feature is deemed critical, it may be needed retroactively for current fire alarm systems. Fire protection engineers advise choosing a design that is adaptable and easy to upgrade if necessary.

The following suggestions can help to improve the long-term reliability of fire alarm systems:

• Future component failures should be considered in the design, and their replacement should be made as simple as possible.
• Choosing the appropriate equipment while keeping situational and environmental factors in mind.
• When necessary, use listed enclosures (UL or equivalent) to protect components.
• Working with dependable manufacturers with a local presence to ensure that replacements are available when needed.

As previously stated, fire alarm systems detect fire and smoke and activate signaling devices such as horns and strobe lights. Fire alarms, on the other hand, can be activated by other inputs:

• Manual pull stations that occupants can activate directly. Manual stations are useful when there is visible fire or smoke but the alarm has not yet responded.
• Water flow sensors in fire sprinkler systems can also activate fire alarms. Water movement indicates that a fire has triggered sprinklers somewhere in the building because sprinklers open with heat.

When owners and facility managers are away from the building, fire alarm systems can alert them. Most importantly, fire alarms can notify the local fire department, allowing for a prompt response. Even when fire alarms are not required, automatic sprinklers are recommended to supplement them because they can extinguish many fires on their own.

A fire alarm system can be in one of three states: normal, alarm, or trouble. The control panel constantly displays the current state.

• When no fires or performance issues are detected, fire alarm systems operate normally most of the time.
• The alarm state indicates that a fire has been detected, either directly through smoke or heat sensors or indirectly through flow measurement in the sprinkler system. When a manual pull station is used, the system also enters the alarm state.
• The trouble state indicates that there is a problem preventing the alarm system from working properly. An open circuit frequently causes a trouble state by interrupting the power supply for system components.

A malfunctioning fire alarm system cannot reliably detect fires, and the cause must be identified and resolved as soon as possible. If a fire occurs while the alarm system is malfunctioning, the building owner may face severe legal ramifications, and the insurance company may refuse coverage for any damage caused.

An end-of-line resistor can be used to detect open circuits. While voltage and current are measured, the resistor is connected at several points between the last device and the control panel. The fault location can be determined by observing how voltage and current behave at various connection points.

A fire alarm system goes into trouble if there is a communication problem that prevents notifications. To ensure that all communication systems are functioning properly, the system sends test notifications at regular intervals.

The following are the primary components of a fire alarm system:

Devices that initiate

Auxiliary devices used in fire alarm systems include LED remote annunciators, LED zone indicators, alarm silencing switches, and electromagnetic door holders.

Identifying appliances

Indicating appliances supplement the function of initiating devices by announcing the activation of the alarm system. Horns, strobe lights, chimes, and bells are examples of indicating appliances. These devices may be weatherproof or rated for hazardous locations, depending on the application.

The control panel

The user interface, branch circuit connections, and all electronic components required to operate the fire alarm system are all housed in the control panel. Each alarm zone has its own circuit board, which allows for changes and maintenance without affecting other zones. The control panel displays the system status and includes a touchpad for user input.

Engineers in fire protection recommend installing the control panel in a staffed or centralized location. The building security headquarters, the telephone switchboard room, or a maintenance office are all viable options. The control panel continuously monitors the voltage and current on all zone circuits, detecting potential problems as soon as they arise.

Batteries that are sealed

Backup power for fire alarm systems is provided by sealed batteries. Because fire can damage a building’s electrical circuits, fire alarms cannot rely solely on them. A fire alarm system with backup batteries can continue to function even if the electrical installation is damaged. Sealed batteries can be housed within the fire alarm control panel or in a separate enclosure. Fire alarm batteries function similarly to emergency lighting batteries.

Auxiliary equipment

Auxiliary devices used in fire alarm systems include LED remote annunciators, LED zone indicators, alarm silencing switches, and electromagnetic door holders.