User Manual

28
Siemens Switzerland Ltd
Building Technologies Division
4.2.3. Alerting visitors
Visitors can be warned of the impending danger in several ways.
Acoustic alarms Electronic sounders are regarded as the normal means of raising an alarm and
are suitable for most applications. The recommended sound level of such devices
(according to EN54-3) should be not less than 65 dB(A) or 5 dB(A) above the
ambient noise level.
Visual alarms Strobes or rotating beacons may be regarded as supplementary alarms which
enhance the effectiveness of sounders, with sounder beacons combining the
advantages of both device types. Beacons are of particular importance for
hearing-impaired persons.
Where several beacons may be visible within a single area it is important that
they are synchronized to avoid the risk of persons with photosensitive epilepsy
suffering a seizure.
Voice alarms A voice alarm system consists of a network of speakers distributed throughout
the building, which permit prerecorded voice messages to be transmitted either
manually or automatically by an alarm from the fire detection system. Such
systems may be applicable in large municipal museums, as different messages
may be conveyed to different areas within the premises.
The effectiveness of such a system can be considerably improved by the live
voice message feature. This allows the person responsible for an orderly
evacuation to address people in specific areas of the building directly and
consequently get their full attention. The better the people are informed, the
more efficient an evacuation will be.
4.2.4. Alerting the municipal fire service
The municipal fire department may be alerted in one of two ways:
· Automatically via the fire detection system by remote transmission
· Manually from the admission desk or security manager’s office by telephone
In certain regions the initial alarm may be transmitted to an Alarm Receiving
Center (ARC) which, in turn, will notify the local fire department.