Fire alarm control panel

The panel receives information from devices designed to detect and report fires, monitors their operational integrity, and provides for automatic control of equipment, and transmission of information necessary to prepare the facility for fire based on a predetermined sequence.

The panel may also supply electrical energy to operate any associated initiating device, notification appliance, control, transmitter, or relay.

Coded panels were the earliest type of central fire alarm control, and were made during the 1800s to the 1970s.

Lists of codes had to be maintained, sometimes with copies posted above pull stations (this setup is commonly seen in older wings of hospitals).

In a conventional fire alarm system, the information density or resolution is limited to the number of such individual wired circuits installed.

To facilitate location and control of fire within a building, the structure usually is subdivided into distinct identified areas or zones.

An Initiating Device Circuit (known as a Signalling Line Circuit (SLC) in addressable systems) connected to multiple devices within the same "zone" of protection, effectively provides 3 distinct states of information about the zone to the panel: Normal, Trouble, or Alarm.

An important output of any alarm control panel is the Notification Appliance Circuit (NAC).

Larger systems and increasing demand for finer diagnostic detail beyond broad area location and control functions expanded the control by zone strategy of conventional systems by providing multiple initiating circuits within a common zone, each exclusively connected to a particular type of initiating device, or group of devices.

Even larger systems and demands for finer diagnostic and location detail led to the introduction of addressable fire alarm systems, with each addressable device providing specific information about its state while sharing a common communication circuit.

Addressable panels are usually more advanced than their conventional counterparts, with much greater information capacity and control flexibility.

Addressable fire alarm panels were introduced by many manufacturers during the microcontroller boom in the mid 1980s.

The Arcnet protocol has been used for years in industrial applications, and is also used for networking Fire Alarm Control Panels.

Releasing panels are capable of using solenoids to disperse fire-fighting chemical agents such as Halon or water from piping located throughout a building.

In nearly every state in the US, the International Building Code requires fire alarm and sprinkler systems to be monitored by an approved supervising station.

A fire alarm system consists of a computer-based control connected to a central station.

The majority of fire alarm systems installed in the US are monitored by a UL listed or FM Global approved supervising station.

This function (also abbreviated as "ACK") is used to manually acknowledge an abnormal situation such as an alarm, trouble, or supervisory signal.

This usually stops the panel "piezo" from sounding, and makes the activated (flashing) LED turn on steady ("go solid").

This button (also known as "flash test") is still used on many panels to check the condition of the indicator lights (LEDs) themselves.

A "silent walk test" will only flash the alarm light on the panel, thus not sounding the signals.

However, building personnel often notify these agencies in advance anyway, in case an alarm is inadvertently transmitted.

This button, or input terminals connected to an external timer switch, will sound the notification appliances briefly in a different cadence from the fire alarm sequence.

This ensures pupils are familiar with the sound of the alarm, and means the notification appliance circuits are tested several times a day.

Many panels today have the capability of alerting building personnel of a situation which could develop into a potentially serious problem.

Fire alarm panels indicate an abnormal condition via a solid or flashing LED.

When an alarm is initiated for a drill, the fire department or monitoring company is usually not notified automatically.

This is mostly used in areas where false alarms are a common problem, or in large applications (such as hospitals) where evacuating the entire building would not be efficient.

[3] Depending on the system's layout, the Notification Appliance Circuit (NAC) may or may not activate for prealarm conditions.

This signal indicates that a portion of the building's fire protection system has been disabled (such as a fire sprinkler control valve being closed, and consequently a sprinkler tamper switch being activated), or less frequently, that a lower-priority initiating device has been triggered (such as a duct smoke detector).