Basic Electrical Installation Work

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5 19.20 2.28 Reproduced from the IEE Site Guide kind permission the Institution Electrical Engineers.82 4 4.02 4 9.251 2.20 and therefore the cable resistance under fault conditions will be: 0 585 702 .74 50 0.20 1.5 10.61 4 1.78 35 1.5 14. Ω The total earth fault loop impedance therefore: ZS 702 202 .911 1.15 1.23 – 16 2.Overcurrent, short circuit and earth fault protection 249 Table 12. Ω.44 10 4.10 1.71 4 2.1 Table the IEE Site Guide: Value Resistance/Metre for Copper and Aluminium Conductors and per Metre 20°C in Milliohms/Metre Cross-sectional area (mm2 ) Resistance/metre (R1 R2)/ metre (mΩ/m) Phase conductor Protective conductor Copper Aluminium 1 18.66 16 1.5 12.30 3.82 25 0. .5 30.20 25 2.5 1.5 2. given Table the Site Guide.20 1.22 6 3.10 1 36.08 6 2.64 50 1.51 2.41 2.5 1.048 1.91 10 3. this case the factor 1.877 – 25 1.114 1.87 35 1.774 1.51 2.557 – 25 1.69 6 6.16 10 1.40 35 0.07 35 1.91 16 4.51 50 0.727 1.5 24.524 0.5 7.49 6 7.84 50 0.83 10 6.387 0.454 2.98 – 16 2. .5 25.5 12.674 2.5 16