Security Oxford

In the event of a fire doors can play a crucial role; they can contain the spread of fire and smoke within the building as well as providing access and escape routes where necessary. but many automatically operated doors are controlled by an electrically powered system which activates the mechanisms that unlock, release or open the doors.

So, obviously, it is essential that these control devices do not fail, not only to slow the spread of fire, but also to ensure the safe evacuation of a building. It is the job of the fire detection and alarm system to control the door release mechanisms, including the automatic failsafe triggers for any faults on the equipment, wiring the power supplies. The primary purposes of these devices is the activation element and, to ensure this happens, as with all specialist electrical equipment, it is vital they are maintained and monitored correctly.

There is often an assumption that door release mechanisms will operate in the event of a fire and fail safe should they lose power:but if the wiring and power supplies to such devices are not monitored continuously there is a chance that they may not function when needed. In the case of electrically activated door locks, which are increasingly being used in properties today, a failure of the wiring or power supply may be even more critical, as people may not be able to exit the building during a fire. So the power and the critical wiring path to these devices need to be secure at all times.

There are several recommendations which need to be considered for the correct design, installation, commissioning and maintenance of the electrical control arrangments covered by the relevant safety standard. Another key area is ensuring that door release mechanisms perform their role- from the initial risk assesment stage through to the correct fitting of devices according to the fire plan. it is equally important to understand the automatic fail safe triggers for any faults on the equipment, wiring or power supplies and how it applies to all aspects of the interface between these devices and the fire detection control panel.

It is at the risk assesment stage when the level of protection for the FDA is decided and the control and monitoring of the door release mechanisms will be placed into one of three categories, depending on the degree of failsafe funcionality. The choice of appropriate category is usually made by the risk assessor and is dependant on the building type and the position of the door. For example, in some buildings, such as eldery care homes, doors closing unexpectedly may be an issue as a person could be injured if a door suddenly closes. Consideration also needs to be given to isolation facilities so testing of the fire alarm system will not interfere with the building security or operation. If doors are closed for security activates or it is a false alarm all parties need to agree a clear fire plan to ensure release devices are triggered in real emergencies.

The designer plays a pivotal role to ensure that the door release mechanisms provide an adequate level of protection for a building. Starting by preparing the Fire Plan, the designer takes responsibility for the whole system, including the types of mechanisms which should comply to the relevant British Standards and any manual actuation or manual isolation faicilty that satisfies the Fire Plan. The designer will also consider all of the operational requirements based on the building type, area of the building, and the specific door mechanism. As a general rule, all fires must release all mechanisms, however there are a number of exceptions such as when there are secure or powered doors, separate alarm zones, a staff alarm arrangement or it’s in a place of lawful detention. Based on the various scenarios the designer will work out the specific details for the Fire Plan. For example, in the case of powered sliding doors or electronically controlled secure doors the designer will consider what the expected actuation is for manual release or manual override devices, as well as work out the activation of release mechanisms on faults as well as fire.

Detector positioning and spacing of the smoke detectors also falls under the deigner’s brief. Safety labels and notices are also the responsibility of the designer, so manual release controls on secure doors for instance, must have a suitable label and be in clear vision of the door.

The final piece of the door release mechanism jigsaw is the funcionality of the control panel which, until a few years ago, was one of the main issues facing the fire industry. Surprisingly, when standard BS7273 was first introduced in 2007, none of the existing fire control panels could provide the monitoring or control denanded; this is not the case today. However, it is important to verify that the fire panel will comply with the requirements on systems especially whose with complex fire plans. Simple checks are essential, such as ensuring the release mechanisms do not reactivate before the system is fully reset. Regular maintenance of the devices is equally important and the British Standard calls for periodical testes to be carried out.

In today’s environment where health and safety issues are a prime concern for a building’s owner/occupier, it is essential that the British Standard for a fire alarm system is met. the door release mechanisms may only be a small part of this system, but their role in preventing fire from spreading and giving building occupants enough time, to escape from flames and smoke play a critical role in fire security.