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EN54-23 Standard for Visual Alarm Devices

The EN54-23 Standard for Visual Alarm Devices (VADs) becomes mandatory at the end of December 2013.  Visual Alarm Devices in the form of beacons or combined sounders and beacons have been a key component of fire alarm systems.  They provide a visual display in the event of a fire that warns people who may not be able to traditionally hear the fire alarm being sounded. 

EN 54-23:2010 (Fire detection and fire alarm systems. Part 23: Fire alarm devices - Visual alarm devices), has been introduced to standardise the requirements, test methods and performance of Visual Alarm Devices and ensure light output is measured in a uniform manner. This standard will be mandatory throughout Europe from 31st December 2013. Visual Alarm Devices are designed to protect the deaf or hard of hearing, and those working in areas which are often very noisy, such as factories or workshops.  EN54-23 was originally introduced in June 2010 in order to set stricter guidelines on the installation and performance requirements of Visual Alarm Devices. March 31st2013 saw the introduction of a revised BS5839-1 code of practice for the design, installation, commissioning & maintenance of FD&A systems in non-domestic premises (& BS5839-8 for voice alarm systems).

Up until 2010 there had been no harmonised uniform European standards or specification.  There were issues with light output performance criteria and installation requirements which resulted in unnecessary confusion, inconsistency and unnecessary danger.

On 31st December 2013 all Visual Alarm Devices, covered by the scope of EN54-23 must conform to the new European specification standard.  The Fire Industry Association (FIA) recommends that where a conflict exists in assessing an installation to the 2013 editions of BS5839-1 & 8 with respect to the VADs used, the requirements stated in the codes of practice be deferred until the end of the coexistence period of E54-23 which is 31st December 2013. A variation in accordance with clause 7 of these codes of practice should be noted on the certification.

Visual Alarm Devices are likely to be applied different in buildings.  Compliant products are only permitted to emit a red or white light and are classified into three distinct categories based on their intended application – ceiling mounted devices, wall mounted devices and an open class category. The specified light output is 0.4 lumens per m2 or 0.4 Lux and manufacturers will have to ensure their VADs are tested and assessed by an EU notified body to determine coverage volume, based on the distance at which the required illumination is met.

One area highlighted as being of imminent need would be in hotel bedrooms and toilets where the obvious benefits of a Visual Alarm Device become immediately obvious for those with hearing difficulties.

Coverage Volume

The need for Visual Alarm Devices should be recognised as part of the fire risk assessment. As with any fire alarm system, there are numerous challenges that must be considered in the design and installation of VADs.

Visual Alarm Devices must illuminate the entire volume of open space where the alarm is visible.  The Visual Alarm Device must illuminate the space to such an extent that an individual located anywhere in the area, facing any direction would be alerted instantly in the event of a fire.

The performance of VADs is assessed against a minimum required illumination of 0.4 lux on surfaces perpendicular to the direction of the light emitted from the device.

As previously mentioned under the EN54-23 standard, Visual Alarm Devices will be classified into three categories based on their application:

W - Wall-mounted
C - Ceiling-mounted
O - Open Category

Wall and Ceiling mounting categories are specified at specific installation heights and particular patterns of coverage - see below.

In wall mounted and ceiling mounted applications of visual alarm devices, EN54:23 indicates the shape of the volume covered is fixed by the standard. The dimensions of this coverage volume are specified by the manufacturer. For all categories, the volume covered can be used to determine Visual Alarm Device spacing within the building.

Open category allows manufacturers to specify the coverage shape and volume and does not put any restriction on mounting height.

W Category (Wall-Mounted Visual Alarm Device)
Coverage Volume

Wall-mounted Visual Alarm Devices (VADS) cover a cuboid volume with a square floor area. The coverage volume is presented as a code in the form of W - X - Y, where W = Wall-mounted category, X is the maximum mounting height (m) and Y is the width and length (m) of the coverage floor area - see diagram. The minimum mounting height allowable by the standard is 2.4 m.

C Category (Ceiling Mounted Visual Alarm Device)
Coverage Volume

Ceiling mounted Visual Alarm Devices VADs cover a cylindrical area. The coverage volume is presented as a code in the form C - X - Y, where C = Ceiling mounted category, X is the maximum mounting height (m) and Y is the diameter (m) of the coverage volume’s floor area - see diagram. The maximum mounting height can only be specified as 3, 6 or 9 m.

Designing with EN 54-23 VADs

When designing systems with Visual Alarm Devices (VADs), a number of factors should be considered:
Ambient light level whether VADs are wall or ceiling mounted
Location of Visual Alarm Device (Wall mounted / Ceiling Mounted)
Visibility to occupants and whether the Visual Alarm Device (VAD) relies on an individual looking at the beacon or whether they need to rely on the light being reflected.

  07 Jan, 2014