cold flexible cable

The actual current carrying capacity of the ÖLFLEX CLASSIC 110 25G1.5 multicore cable presents an important distinction that often confuses engineering professionals who are unfamiliar with multicore cable ampacity concepts. The baseline ampacity, calculated under idealized conditions where a single conductor is installed in isolation and carries current at 30°C ambient temperature, is approximately 18 amperes per conductor. However, when all twenty-five conductors are bundled together in the cable and simultaneously carry load—as would occur in an industrial facility where a multiconductor cable distributes power or control signals to numerous equipment connection points—the actual safe current rating for each conductor drops dramatically to approximately 7.2 to 8.1 amperes. This profound reduction from 18 amperes (baseline) to 7.2–8.1 amperes (practical) represents the aggregate effect of multiple derating factors that reflect real-world thermal conditions: the thermal coupling between adjacent conductors (where heat generated in one conductor makes it harder for neighboring conductors to dissipate their own heat), the insulating effect of the cable’s outer sheath (which traps heat rather than allowing free convection cooling), and the reduced heat dissipation efficiency when multiple cables are installed together in cable trays or conduit. Understanding why this reduction occurs and how to calculate it accurately is essential for electrical engineers designing safe, reliable control systems and power distribution systems using multicore cables.