ISO 7240-24:2016

Overview

ISO 7240-24:2016 - "Fire detection and fire alarm systems - Part 24: Fire alarm loudspeakers" defines the requirements, test methods and performance criteria for loudspeakers used to broadcast fire warnings from a fire detection and alarm system to building occupants. The standard covers two application environments: Type A (generally indoor) and Type B (generally outdoor) loudspeakers. It excludes special hazardous-area loudspeakers, addressable loudspeakers and loudspeakers with active electronic components; audible alarm indicators are addressed in ISO 7240-3.

Key Topics and Requirements

ISO 7240-24:2016 organizes requirements and tests to ensure audibility, reliability and durability of fire alarm loudspeakers. Key technical topics include:

• Scope and definitions - terminology for loudspeaker types, rated impedance, sensitivity and coverage angles.
• Acoustic performance - frequency response limits, sensitivity (sound pressure level), maximum sound pressure level (SPL) and horizontal/vertical coverage angles.
• Durability and electrical characteristics - rated impedance, rated noise power testing and long-term endurance.
• Environmental and mechanical tests - dry heat, cold, damp heat (cyclic and steady-state), sulfur dioxide corrosion, shock, impact, vibration (operational and endurance).
• Ingress protection and construction - enclosure integrity, materials, provisions for external conductors and access for maintenance (IP testing and requirements).
• Test methods and tolerances - atmospheric/operating conditions for tests, mounting arrangements, reproducibility, test schedule and detailed measurement procedures (acoustical annexes).
• Documentation and marking - required data, test reports, and marking information to demonstrate compliance.

Applications and Who Uses It

ISO 7240-24:2016 is used by professionals involved in design, manufacture, installation and certification of fire alarm voice evacuation and public address interfaces:

• Loudspeaker and system manufacturers - to design products that meet fire safety performance and environmental durability criteria.
• Fire alarm system designers and integrators - to select loudspeakers with appropriate SPL, coverage and environmental ratings (Type A/Type B) for buildings.
• Testing laboratories and certification bodies - to apply standardized test methods and produce compliance reports.
• Specifiers, consultants and building owners - to ensure installed voice alarm components meet recognized safety standards and achieve intelligible evacuation messaging.

Related Standards

• ISO 7240-1:2014 - general requirements for fire detection and alarm systems (reference figure for loudspeaker role).
• ISO 7240-3 - audible alarm indicators.
• Other parts of the ISO 7240 series covering detectors, control and indicating equipment, and system performance.

Keywords: ISO 7240-24:2016, fire alarm loudspeakers, fire detection and fire alarm systems, loudspeaker requirements, test methods, performance criteria, indoor/outdoor Type A Type B, ingress protection, acoustic performance.