Fire impression tests cables
At least a quarter of fires are caused by an electrical problem in (household) equipment or installations. This is usually the result of a faulty design. In addition, the fire safety performance of the cables also plays a role.To get an impression of the fire behaviour of two different types of cables and their influence on the possibility of escape and survivability, the Fire Service Academy of the IFV has carried out a number of so-called impression tests. The tests were conducted on behalf of Europacable; European trade association for the cable industry.
– What is the fire behaviour in a single room environment of high performance cables and basic performance cables when exposed to an ignition source of burning methanol?
What is the probability of escape and survivability in a single room environment when only the cables are burning?
– How does a fire propagate and develop in an office environment with a fire starting in the basic performance cables?
– What is the probability of escape and survivability in an office environment with a fire starting in the basic performance cables?
Fire development and fire propagation
It turns out that a fire develops slowly in high performance cables and reaches its maximum size after 10 minutes. Such cables burn only in the part where they are impinged by the flames of the ignition source; further away from the ignition source, the flames extinguish automatically. In contrast, in low- performance cables, the fire develops very quickly and reaches its maximum size after 4.5 minutes; after 10 minutes the cables are completely burned away. In addition, where the cables are attached horizontally, flaming droplets fall down and continue to burn on the floor, causing secondary fires. The tests in the office environment have shown that a fire easily spreads over the low performance cables. After 3 minutes, heat radiation causes the fire to also spread to the desk; burning droplets cause the carpet to catch fire, as well as the office chair and other objects in the room. The result is a flashover after 7 to 8 minutes.
Possibility of escape and survivability
A fire in both high and low performance cables in a room with the door open does not appear to result in an impaired escape or life-threatening situation. But if the door were closed, irritating and asphyxiating gases could potentially reach higher concentrations and the temperature would rise, with different results. The tests with the low- performance cables in the office environment have shown an impaired escape after 5 to 6 minutes, and that shortly afterwards (5 to 7 minutes) a life-threatening and fatal situation follows. Both heat and irritating and asphyxiating gases play a role in this.