Newsletter

Selecteaza Domeniu:

SR EN 54-24

EN 54-24 (SR EN 54-24) – Overview

Standard Name: Systems for fire detection and alarm 

Part 24: Components of voice alarm systems Speakers

It is a component standard – Speakers, released in February 2008 (IEC EN 54-24; SR-EN 54-24). It shall apply from 1 April 2011.

Introduction:

The purpose of a speaker in a voice alarm system is to provide intelligible warnings for the persons inside (outside) of a building and to enable them to take appropriate measures specified in the plan of evacuation/ rescue. In standard are specified the minimum requirements for speakers and a method for verifying its. Are specified constructive and strength requirements of voice alarm speakers.

Requirements:

–  Characteristic frequency  to fit into the domain indicated in standard

– Speaker must be designed for a lifespan of 100 hours at nominal power indicated by the manufacturer

– Connection terminals must accept wire diameter 0,8-2,5mm

Marking and documentation:

– Environment type A(indoor applications IP21C) or B (outdoor applications IP33C)

– The name of the manufacturer or supplier

– Model

– Description of connection terminals

– Nominal voltage for speakers with transformer

– Nominal impedance for the speakers connected directly

– Nominal power measured according to standard

– Power take off (PTO)

– Identifier of the lot

The documentation shall indicate:

– Frequency response for each reference axis indicated

– The Sensitivity

– Horizontal and vertical angles of coverage at 500Hz, 1kHz, 2kHz, 4KHz

 – Maximum sound pressure level (at the maximum)

– Axis of reference

– Nominal power measured according to standard

– Frequency response in 1/3 octave band

– The acoustic environment measuring  (open field, free hemispherical field, standard baffle)

In continuation of the standard are presented:

– Test methods

– Basic measurements testing program

– Endurance tests ( wet and dry heat , with sulfur dioxide corrosion , shock , impact, vibration).