Networked Fire Systems – What To Consider?

Have you ever really thought about what your fire panel has to do?

The demands on today’s fire systems have never been greater – and not all panels are created equal – which can make choosing the right solution a challenge.

Many fire panels are now powerful computers, working with intelligent detectors to constantly report on changing conditions across the fire system. They are relied upon to alert people to real and potential emergencies by voice, light and/or sound. They allow you to control evacuation procedures so that people get out of complex buildings safely in any fire situation.

Some panels are fine-tuned to reduce the number of false alarms. They are also required to control the release of suppressants, operate smoke control systems, manage appropriate closure and release of fire doors, link to graphical control systems and interact with third-party building management systems. The list is long – and constantly growing.

The demand for fire panels to do all this – and more – over 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?

 

Are the panels quick and easy to set up as a network?

Flexible system architecture

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.

The network’s design should allow buildings to be protected by distributing 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 anycontrol panel. This allows the system to display details of all fires, alarms, pre-alarms and faults on any panel or repeater in the building.

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 any one panel can be made available to any or all of the other panels in a network, allowing the user to access all the information on the system from any one panel. This provides both the benefits of distributed intelligence and reduced installation costs.

 

Will the network perform properly over large areas?

Speed of the system

In large, complex sites, it’s vital to ensure that the panels, when networked, will sustain adequate performance levels. As the number of panels and input and output options on a network increase, some systems can slow down dramatically. This can seriously compromise safety and reliability.

Different systems offer various approaches to networking. These can vary from master-slave systems to peer-to-peer standard or fault-tolerant networks, as in Advanced’s case. However, as with all systems, the speed at which a fire signal can be transferred around the network is critical to performance.

Advanced’s networks can be configured to allow the inter-connection 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 standard two-core, fire-resistant cable.

Both EN54-13 and UL864 specify maximum times for relaying fire alarm 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 20sec.” 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 3.5 seconds for a full 200 panel system.

 

Networking Bishopsgate

At the centre of the active fire protection for the City of London’s 62-storey high 22 Bishopsgate are over 80 networked MxPro 5 panels with graphic display and BMS integration, alongside three special build panels for the building’s Fire Command Centre, that form part of the intelligent fire detection network. 

 

Network, design and composition

Networks can be built using standard fire cable or fibre optics and are often required 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, and so are worth seeking for added peace of mind, especially on larger sites.

Fire happens fast, so seconds matter, and fast, efficient networks are vital. The highest quality networking should be a key specification, especially on larger sites where the network will be handling more information from more devices.

 

Will the network be easy to use and maintain?

Operation of the system

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 with extensive networking capability 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.

Historically, many different networked systems were based on star, radial and loop typologies. Today, to ensure greater system security, a looped system is recommended as it uses diverse cable routing techniques. Should a single fault occur, affecting communications, the system can still function and communicate to provide a co-ordinated response.

  

Networking Swansea Uni

A 25-panel network from Advanced is installed at Swansea University’s £450m Bay Campus. MxPro 5 panels are specified thanks to their superior networking capabilities and are considered by installers as the ideal solution when protecting large-scale sites with multiple buildings that each have individual cause and effect programming.

 

Will it be easy to expand the system if I need to?

Scalability and cause and effect

A truly scalable fire network will allow different typologies suitable for sites of various sizes with vast cause and effect options. Networks designed within buildings generally use standard fire-resistant copper cable. However, as buildings are increasingly networked, fibre optic cable has become the preferred medium. This allows your fire alarm network to cover significantly greater distances.

The nature or purpose of a building area needs to be considered when networking systems. 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. This is especially the case when complex systems may potentially be linked to graphical alarm reporting systems.

 

Networking Delimara

At Delimara Power Station in Malta, an Advanced fire system protects the diesel engine plant that generates 149MW of electrical energy for the island. The networked system has over 700 individual components and over 7km of cable runs. It comprises 16 loops in total, with four MxPro 4 panels and repeaters in the station’s main control room that provide the status of the entire fire alarm system. The panels are integrated with water-based sprinkler systems, deluge foam systems and inert gas suppression to provide a total fire detection, alarm and control system.

 

Conclusion

In complex buildings, the fire system may be managing a wide range of inputs and outputs as a fire spreads, including smoke control, graphical indication, voice evacuation, door closers, direct connections to monitoring stations, gas suppression, etc.

The fire system needs to work quickly and reliably, and process large numbers of changing signals in the event of a real fire situation. On larger sites, seconds count and fast systems are highly valuable in maximising 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, maintain and can it easily be expanded in 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?

Individually, many fire systems may appear to meet the challenges posed on large-scale sites. However, in complex buildings these systems are likely to be networked and attaining adequate performance levels under these circumstances isn’t always achievable with inferior fire panels.

As the number of panels and input and output options on a network increase, so does the need for a high-performance networked system that will deliver reliability and resilience. It must also offer network cabling solutions that are scalable, accommodate sophisticated cause and effect and facilitate system architecture that can adapt to the size and purpose of a building.

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