Cabling and fire safety
Posted on 26th May 2021
The fire resistance of insulated cables plays an important part in building safety.
It must be easy for building designers, specifiers, and contractors to identify and install suitable cables that can survive real-life fire conditions.
Fire resistance testing for cables
Currently direct impact testing isn’t required for fire-resistant cable under 20mm.
There is a test for fire with water, but the pressure in this test is much less than you would expect from a standard household sprinkler, a commercial application, or a fire hose, for example. In contrast, fire-resistant cables that are more than 20mm are tested for direct impacts and water jets.
A fire survival classification
There is growing awareness in the construction industry that all stages of a building’s lifecycle need to be planned and managed. A higher fire survival classification for cables which can continue to power critical circuits is important.
In the event of a fire these cables would withstand events like falling debris, collapsing walls, fire hoses, or activation of high-pressure sprinklers and smoke extraction.
Fire survival cables are essential to support a building’s safety so accurately measuring and specifying tolerances is needed at the design stage. Changes to BS8629 recognise that in many cases fire-resistant cables, including those in fire alarm and fire safety systems, might not survive direct impacts during a fire.
Retardant vs resistant
Fire retardant cabling is designed to resist the spread of fire into a new area while fire resistant cabling is designed to maintain circuit integrity and continue to work for a specified time under certain conditions.
Both play an important part in maintaining the integrity of a building during a fire and improving the chances of escape and survival.
Fire resistant cables are often used in public buildings such as schools or hospitals, as well as railway stations, retail, leisure venues, and hazardous environments.
If you have special cabling requirements please get in touch.
Tagged as: Electrical safety
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