The demands on today’s fire systems have never been greater, but not all panels are created equal, which can make choosing the right solution a challenge.
Many fire panels are relied upon to alert people to real and potential emergencies, control evacuation procedures, and reduce the number of false alarms. They are also required to control the release of suppressants, operate smoke control systems, manage the closure and release of fire doors, link to graphical control systems, and interact with building management systems.
The demand for fire panels to do all this – and moreover larger and more complicated sites, as part of a fire network, is increasing. And with this requirement come important questions, such as:
- Are the panels quick and easy to set up as a network?
- Will the network speed/performance, over a large area, be compromised?
- Will the network be easy to use and maintain?
- Will it be easy to expand the system?
Flexible system architecture
A good network design will distribute the fire panels throughout the site A networked fire alarm system communicates data between all panels/network nodes on a site, allowing for greater control over the fire safety of the entire building. A good network design will distribute the fire panels throughout the site, instead of having to take all the detection circuits back to a single point. Using a true peer-to-peer system, information from any input or output device can be passed over the network and displayed on any control panel.
The inter-connection of fire alarm control panels over a proprietary network is well established, allowing many panels, often sited in physically different locations, to communicate between each other using a two-core cable (or fire-resistant, two-core, screened twisted pair cable depending on your local legislation). Information from anyone panel can be accessed from all other panels in a network, allowing the user to access all the information on the system from any panel.
Speed of the system
In large, complex sites, as the number of panels and input and output options on a network increase, some systems can slow down dramatically, seriously compromising safety and reliability. Both EN54-13 and UL864 specify maximum times for relaying signals around the network. For example, the standard EN 54-13:2005 (E) 4.3.2.1 states that “a fire alarm condition on Control and Indicating Equipment (CIE) shall be indicated on the main CIE within 20 seconds.”
Advanced’s networks allow the interconnection of up to 200 panels (nodes) in a fault-tolerant configuration. The maximum cable length between nodes is 1.5km, with a total loop length of 20km. The network is capable of withstanding a single fault between nodes without loss of communications to any single panel. This is all achieved using a standard two-core, fire-resistant cable.
There’s little point in setting a 60-second acknowledgment time if your network takes 15 seconds to process inputs, as that’s 25 percent of the time available. The typical delay on an Advanced Ad-NeT+ 50 panel network, for each panel to indicate a fire from any zone, is less than one second, and it’s just 3.5 seconds for a full 200-panel system.
Network, design, and composition
Networks can be built using standard fire cable or fiber optics and often need to cover huge distances. The network design, therefore, needs to be resilient and function reliably in a dynamic fire situation, where increased network traffic, higher voltages, and currents, as well as changing environmental conditions, can be challenging.
EN54-13 approved systems are designed and tested to continuously monitor network activity and ensure they perform in a fire situation, so are worth seeking for added peace of mind, especially on larger sites.
Operation of the system
A networked fire alarm system enables the user to access information from any panel on a network or a central location Large fire alarm systems can feature control panels on different floors or in different areas of a building, with each panel controlling and monitoring devices in the area to which it is designated. It’s therefore critical to choose a flexible solution that can be configured to report the status of other panels in the system if required.
A networked fire alarm system enables the user to access information from any panel on a network or from a central location. This overall system view saves those charged with maintaining these systems from having to visit multiple physical locations.
Scalability and cause and effect
A truly scalable fire network will allow different cabling typologies suitable for sites of various sizes, with a vast choice of cause and effect options. Networks designed within buildings generally use standard fire-resistant copper cable. However, as buildings are increasingly networked, fiber optic cable has become the preferred medium.
The nature or purpose of a building area also requires consideration. For example, detectors will be grouped to allow appropriate alarm annunciation, so systems need to provide enough zones. Depending on the size of the site, a fire alarm network may have multiple panels, hundreds of zones, and thousands of devices. Therefore, the need for sophisticated cause and effect and intuitive, easy programming of rules becomes crucial.
Conclusion
In complex buildings, the fire system needs to work quickly and reliably, and process large numbers of changing signals in the event of a fire. On larger sites, seconds count and fast systems are highly valuable in maximizing the time for verification, escape and firefighting.
When selecting the most appropriate networked fire system, it’s important to ask:
- Can information be displayed clearly and logically across the whole site?
- Is the system truly scalable?
- Is it easy to program and maintain, and can it easily be expanded in the future?
- Will the system perform correctly and are its cause and effect capabilities adequate?
- Does the network offer appropriate levels of reliability in the event of a fire or fault?
