The Siemens Building Technologies Division has introduced a new intermediate base for the optical-acoustic fire alarm.

The intermediate base meets the special requirements for optical alarms according to the latest European EN 54-23 standard and offers increased protection by stimulating two senses in the event of an alarm. Standards-compliant products adjusted to the signal range meet the required illumination, light color and flash rate specified in EN 54-23. The intermediate base with white LEDs has a signal range of C-3-5 maximum. That means that an intermediate base mounted on the ceiling at a height of up to 3 meters covers a cylindrical signal range up to 5 meters in diameter.

The loop-fed intermediate base requires no additional wiring. It is installed between the automatic fire detector and its connection base and communicates via the detector bus. The isolator installed in the unit and detector-loop topology increase protection against failures. Multiple devices installed on the detector bus also ensure that the sound and flashing lights are synchronized throughout the building. The intermediate base is addressable and can be individually activated for alerting or evacuation. The device can also be installed without a fire detector using the cover plate provided.

The integrated alarm sounder has 13 different signal tones in accordance with EN 54-23, so it can output different tones, e.g. for alerting or evacuation. The volume is adjustable. EN 54-23, which was introduced in June 2010 and took effect in January 2014, is the first uniform European-wide standard for optical alarm devices. The standard sets forth the requirements, testing procedures and performance criteria for these devices, such as requirements for light intensity and distribution. Optical signaling devices certified according to EN 54-23 are especially suitable for areas frequented by individuals who are hard of hearing, such as in hotels, nursing homes and hospitals. They are also practical in areas where the acoustic signals could be missed due to loud ambient noise or the wearing of hearing protection.