Tests for fire detection systems intended for engine compartments

Purpose

The test method described in this document is intended to test and rate the detection performance of fire detection systems installed in engine compartments. The test method also examines the durability of the system components.

To ensure early detection of fire and durability of detection systems, there is a need for fire detectors intended for engine compartments to be tested. Many of the challenges in this environment, are namely not specifically tested for in other standards for fire detection systems. These challenges are, for example, complex geometries cluttered with obstructions, high airflows, high temperatures and hot surfaces, dirt and dust, as well as vibrations, shocks and corrosion. SP Method 5320, considers these challenges, allowing for rapid performance evaluation under realistic and repeatable conditions.

Method

The test method is divided over a number of different categories. Firstly, the complete system is test in a mock-up engine compartment as follows:

• The System Coverage Test evaluates the response time of fire detectors for both small and large fires under varying ventilation conditions. In total 13 different fire scenarios are considered to ensure the detection system has the ability to detect fires starting in practically every possible location in the engine compartment.
• The Response Time Test gives information on and compares the response times of detection systems in two fire scenarios; a slow-growing fire and an instant large flaming fire. This ensures that detection systems are equipped with components that allow for detecting both of these very different fire scenarios.

To secure the surviveability of the fire detection system and its components they are also subjected to component tests. These tests consider their durability to corrosion, ageing, temperature variations, vibrations, schock, EMC as well as ingress of dust and water. Before and after these tests, individual components are also subjected to the following test cases:

• The activation temperature and response time of heat detectors is analysed in the Heat Detection Test. This is done before and after component levels tests, to ensure that these do not affect their function in a negative way. In addition to this, the sensitivity of heat detectors to false alarms is tested.
• Flame detectors are tested in the Flame Detection Test to ensure their sensitivity was not affect by the components tests. Flame detectors are also subjected to field of view tests to guarantee detection ability is preserved for the complete field of view.
• The sensitivity of smoke or as detectors is investigated in a smoke tunnel during the Smoke/Gas Detection Test. Time to activation and obscuration at activation is compared before and after component testing.

Deliveries

After testing, a test report is delivered with the results which may be the basis for product approval (P-mark) according to SPCR 197.