Solar Booklets

www.siechem.com 61 Standard conditions for current rating The tabled values for the current rating were calculated according to IEC 287 for the following standard conditions: Continuous operation single circuit for 3--phase current, single conductor for 1--phase current 30 °C ambient temperature and sufficiently large and ventilated spaces, whose ambient temperature is not appreciably increased by the heat coming from the cables. 120 °C conductor temperature. Frequency up to 200 Hz. Installation in air, unrestricted heat dissipation, means that the following installation conditions are observed: Distance of the cables from the wall, from the floor, from the ceiling greater than cable diameter. Distance between two adjacent power circuits greater than 2 x cable diameter. Vertical distance between power circuits laid one upon another for individual cables greater than 2 x cable diameter and for layers of cables > 200 mm Perforated tray with a perforation > 30 % of the total surface. Open trays are continuous supports with vertical sides, but without cover. A possible perforation accounts for < 30% of the total surface. Closed ducts are entirely closed. Pipes belong to this category also. The max. filling degree is 70%. 0 De rating Factors for Deviating Ambient Temperature (Basis 30 C) Reduction Factors for Different Conductor Temperature Ambient 0 Temp. C Reduction Factor RF1 0 Conductor Temp. C Maximum permitted typical conductor temperature for various insulation materials according to IEC 60216 (20000 h/50 % Elongation at break) 0 Current Rating C Wires & Cables PVC,FRLS XLPE & EPR(Chemical cured) 120 Siechem EBXL - XLPO 120 Material 0 Temperature C 70 20 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 1.05 1.00 0.97 0.94 0.91 0.88 0.85 0.82 0.78 0.75 0.71 0.67 0.62 0.58 0.53 0.47 0.41 0.33 0.22 Reduction Factor RF 2 120 110 100 90 80 70 0.72 0.79 0.85 0.91 0.96 1 90 Siechem EBXL - XLPE