1) Mineral insulated cables are an alternative to standard fire-resistant cables as they are completely uncombustible, extremely robust, and can survive fires rather than just maintain functionality for a limited time.
2) Current fire safety standards have gaps as they do not accurately simulate real fire conditions or account for how the rising temperature affects copper's resistivity under fire.
3) As copper's resistivity increases five times under fire temperatures, the cable temperature rise at full load would be dangerously high, potentially melting the copper, regardless of the length exposed to the fire. All fire standards would need to be upgraded to account for this.
18. andpriorto all sustainedfunctionalityfor a definedperiod of timeso thataccidentslikethefire at Düsseldorf Airport on 11 April 1996 that left 17 people dead shall have the minimum possible impact – if they cannot be totally avoided.
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21. Mineral insulatedcablescouldbe an alternative! Theyconsistexclusively of metals and minerals Copper conductor, meltingpoint: 1083°C Magnesia oxide, meltingpoint: 2800°C Outer copper sheath, meltingpoint: 1083°C
42. theresistivity of copper risesby a factor of 5!Standards taketheresultingincrease of thevoltagedropintoconsideration – but onlyfor a fraction of thecablelength. Thisisjustifiedbecauseonly a fraction of theentirecablerun will beexposedto a fire…
46. (Of aluminium not eventospeak: 650°C).All relevant standardsdealingwiththisrequire an upgrade! In theory all »fireproof« or »fireretardant« safetycableswouldneedtobedesignedwith 5 timesthecrosssection a standardcablehasforthe same currentrating. In practice a compromiseneedstobefound. After all, mineralinsulatedcableswouldbethebetterchoice in anycase!