Fire alarm control panel
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General Active fire protection Fire suppression Fire extinguishers Fire detection/alarm Fire alarm control panel Practices |
A fire alarm control panel, also referred to as a fire alarm panel or FACP, normally referred to as a panel within the active fire protection industry, is a central control device for detecting, reporting and acting on occurrences of fires within a building. It is an active fire protection item that is subject to stringent bounding. There are two types of panels: conventional panels, and analogue addressable panels.
In a conventional panel, fire detection devices including, but not limited to smoke detectors, heat detectors and manual call points or manual pull stations are joined up with a number connected to each circuit. When a device on the circuit is activated, the panel recognizes an alarm on that circuit and could be set up to take a number of actions including directly calling the fire department via an alarm transportation system (ATS).
An addressable panel is a more modern type of panel, and has greater flexibility than a conventional panel. An addressable panel has a number of loops, where a number of devices are able to be connected, each with its own address. There is no standard protocol as such, and thus a number of proprietary solutions exist. Loop devices have traditionally been able to have 99 or 100 devices connected, but more recent protocols allow many more. This is usually overcome by having multiple loops on one system.
Fire panels are required in the building code for new structures in most countries.
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[edit] Conventional panels
Conventional panels have been around ever since electronics became small enough to make them viable. They are no longer used frequently in large buildings, but are still used on smaller sites such as small schools or apartments.
Conventional panels usually have a small number of circuits, each circuit covering a zone within the building. A small map of the building is often placed near the main entrance with the defined zones drawn up, and LED's indicating whether a particular circuit/zone has been activated. Another common method is to have the different zones listed in a column, with an LED to the left of each zone name.
The main drawback with conventional panels is that one cannot tell which device has been activated within a circuit. The fire may be in one small room, but as far as emergency responders can tell, a fire could exist anywhere within a zone.
[edit] Addressable panels
Addressable panels are usually much more advanced than their conventional counterparts, with a higher degree of programming flexibility and single point detection.
[edit] Loops
Panels usually have a number of loops within the range of two to 20 loops. At the present time, four or six loop panels are the most common.
Each loop can have a number of devices connected to it. Each device has its own address, and so the panel knows the state of each individual device connected to it. Common addressable input (initiating) devices include
- Smoke detectors
- Manual call points or Manual pull stations
- Responders
- Fire sprinkler inputs
- Switches
- Flow control
- Pressure
- Isolate
- Standard switches
Addressable output devices are known as relays and include
- (Warning System/Bell) Relays
- Door Holder Relays
- Auxiliary (Control Function) Relays
Relays are used to control a variety of functions such as
- Switching fans on or off
- Closing/opening doors
- Activating Fire suppression systems
- Activating notification appliances
- Shutting down industrial equipment
Since their inception, loops have generally been able to handle 99 devices. More recently however, new protocols have been designed that allow 256 devices on each loop.
[edit] Mapping
Also known as "Cause and Effect" or "Programming", mapping is the process of activating outputs depending on which inputs have been activated. Traditionally, when an input device is activated, a certain output device (or relay) is activated. As time has progressed, more and more advanced techniques have become available, often with large variations in style between different companies.
[edit] Zones
Zones are usually made by dividing a building into different sections, and placing each device in the building in a different zone.
[edit] Groups
Groups are used to group two or more relays. They are used to shorten programming time by allowing several detectors to link to any particular group which then maps to a group of relays.
[edit] Boolean logic
This is the part of a fire panel that has the largest variation between different panels. It allows a panel to be programmed to implement fairly complex inputs. For instance, a panel could be programmed to notify the fire department only if more than one device has activated. It can also be used for staged evacuation procedures in conjunction with timers.
[edit] Networking
The principle of networking involves connecting several panels together to form a system. Inputs on one panel may activate outputs on another, for example, or the network may allow monitoring of many systems. Networking is often used in situations where one panel is not large enough, or in multiple-building situations.
Although quasi-standards exist that allow panels from different manufacturers to be networked with each other, they are not in favour with a lot of companies (so they are not de-facto at all). One of the most common of these is named BACnet which is used for various type of industrial networks.
More recently, some panels are being networked with standard Ethernet, but this is not yet very common. Most organizations choose to create their own proprietary protocol, which has the added benefit of allowing them to do anything they like, allowing the technology to progress further. This has the serious downside, however, of hampering interoperability between manufacturers.
Networking may be used to allow a number of different panels to be monitored by one graphical monitoring system.
[edit] Monitoring
In nearly every state in the USA, 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 USA are monitored by a UL(r) listed or FM Global(r) approved supervising station.
These systems will generally have a top level map of the entire site, with various building levels displayed. The user (most likely a security guard) can progress through the different stages. From top level site → building plan → floor plan → zone plan, or however else the building's security system is organised.
A lot of these systems have touch screens, but most users tend to prefer a mouse (and a normal monitor), as it is quite easy for a touch screen to become misaligned and for mistakes to be made. With the advent of the optical mouse, this is now a very viable option.
[edit] System functions
There are many functions on a fire alarm panel. Some of these are:
[edit] System reset
This resets the panel after an alarm condition. All initiating devices are reset, and the panel is cleared of any alarm conditions. If an initiating device is still in alarm after the system is reset, such as a smoke detector continuing to sense smoke, or a manual pull station still in an activated position, another alarm will be initiated. A system reset is often required to clear supervisory conditions. A system reset does not usually clear trouble conditions. Most trouble conditions will clear automatically when conditions are returned to normal.
[edit] Acknowledge
This function, also abbreviated to "ACK", is used to acknowledge an abnormal situation such as an alarm or trouble condition. The acknowledge function tells the panel that building personnel or emergency responders are aware of the alarm, trouble, or supervisory condition. Acknowledging the alarm or trouble condition also normally silences the panel's own sounder.
[edit] Drill
Also known as "manual evacuation" or "evacuate". On panels that have this function, the drill function activates the system's notification appliances, often for purposes of conducting a fire drill. Using the drill function, an alarm is normally not transmitted to the fire department or monitoring center. However, building personnel often notify these agencies in advance in case an alarm is inadvertently transmitted.
[edit] Walk A
Initiates an "audible walk" with all notification appliances activated. This will also alert the fire department or monitoring center since their connection is activated in the walk.
[edit] Walk S
Initiates a "silent walk", where only the systems strobes are on and there is no audible sounder.
[edit] Alarm silence
Also known as "audible silence". Depending on the configuration of the alarm system, this function will either silence the system's notification appliances completely, or will silence only the audible alarm, with strobe lights continuing to flash. Audible silence allows for easier communication amongst emergency responders while responding to an alarm. This can also be used during construction as a means of a preliminary test, before the final full test.
[edit] Lamp test
Also known as "flash test". This button is known to have become obsolete, but is still used on many panels. This function is used to check the condition of the LEDs themselves. A "Lamp Test" button is required by code on multi-zone panels installed in Canada.
[edit] Panel alerting
Many panels today have the capability of alerting building personnel of a situation which can arise into a potentially serious problem. Fire alarm panels indicate an abnormal condition is via a solid or flashing LED. Some panels also contain a small sounder, used in conjunction with the visual alert. A number of indicators are shown below. Note that not all fire alarm panels have all of these indicators.
[edit] Alarm (red light)
Also known as "Fire". This indicator is lit when an alarm condition exists in the system, initiated by smoke detectors, heat detectors, sprinkler flow switches, manual pull stations, manual call points, or otherwise. Along with the indicator on the panel, notification appliances, such as horns and strobes, are also activated, signaling a need to evacuate to building occupants. In an alarm condition, the fire alarm panel indicates where the alarm originated. The alarm panel can be reset once the device which initiated the alarm is reset, such as returning the handle of a manual pull station to its normal position.
[edit] Audible silence (red light)
The Audible Silence indicator is used in conjunction with the "Alarm" indicator. It indicates that the fire alarm panel is still in an alarm condition, but that notification appliances have been silenced. While the alarm is silenced, other functions in an alarm condition continue to operate, such as emergency service for elevators, stairway pressurization, and ventilation functions. A new alarm initiation while the alarm is silenced will take the panel out of Audible Silence and reactivate the notification appliances.
[edit] Brigade called (red or yellow light)
This indicator is activated when emergency responders have been automatically notified by the fire alarm system. Requirements vary depending on jurisdiction regarding whether a direct connection to the fire department is required, optional, or prohibited. If a connection to the fire department is optional, or is prohibited, a fire alarm system is often connected to a monitoring center at the building owner's discretion.
[edit] Drill (red light)
On panels containing this function, the "Drill" indicator shows that the alarm condition was activated from the fire alarm panel, often in order to conduct a fire drill. When an alarm is initiated for a drill, the fire department or monitoring company is usually not notified automatically. However, building personnel preparing to conduct a fire drill often will provide advance notice of a drill to the fire department and monitoring center in case an alarm is unintentionally transmitted.
[edit] Trouble/Fault (yellow light)
Also known as "Defect". When held steady or flashing, it means that a trouble condition exists on the panel. Trouble conditions are often activated by a contaminated smoke detector or an electrical problem within the system. Trouble conditions are also activated by a zone being disabled (disconnected from the system), a circuit being disabled, low power on the backup battery, the disabling of a notification appliance, the ground faults, or short or open circuits. Usually the alarm panel's sounder will activate if a trouble condition exists. In a trouble condition, the panel displays the zone or devices causing the condition. The "Trouble" indicator goes out automatically when the situation causing the trouble condition is rectified and some panels have more specific indicators such as 'Trouble-PSU' which shows when the panel itself is compromised and 'Trouble-Bell' which shows that the sounders are not functioning correctly.
[edit] Supervisory (yellow light)
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, consequentially, a sprinkler tamper switch being activated), or, less frequently, that a lower priority initiating device has been triggered (such as a duct smoke detector). The "Supervisory" indicator may go out automatically when the condition has cleared, but usually requires a "Reset" to clear.
[edit] AC power (green light)
Also known as "Normal". When this indicator is lit, power is being provided to the system from the building's electrical system, and not from the backup battery. When an AC power condition changes, the Trouble indicator comes on and the AC power indicator goes off and the screen alerts building personnel of a power failure. If the AC power indicator is lit without any other indicators also lit, then the system is in a normal condition. If no LEDs are lit, there is no power source feeding the panel.
[edit] DC power (green light)
This is used to tell the operator that DC power (batteries) are being charged.
[edit] DC power (red light)
This LED is red when the system is being operated on DC power alone.
[edit] Highrate (green light)
Is on when there is unusual power line conditions.
