What is the difference between standard and enhanced fire-resistant cables in a BS 5839 system?

Under BS 5839-1, standard fire-resistant cables are suitable where the required survival time is 30 minutes, typically for evacuation zones in less complex buildings. Enhanced cables, designated with an ‘enhanced’ marking, provide a minimum 120 minutes of circuit integrity under the BS EN 50200 test and include additional resistance to water spray and mechanical shock as per BS 8434-2. This higher performance is mandatory for systems where fire-fighting operations rely on prolonged alarm functionality, such as high-rise and large public buildings.