Aluminium conductors have higher resistance – roughly 1.6× the copper value.
Next time you pick up a cable, remember: the mm² rating is a promise. The resistance table is the proof. Need to check a specific conductor size or resistance value? Always refer to the latest official edition of BS EN/IEC 60228 (current version: 60228:2005, confirmed to BS in 2019). bs en/iec 60228
If you have ever specified a cable, terminated a wire, or calculated voltage drop, you have relied on BS EN/IEC 60228 – even if you didn’t know it. This standard is the international foundation for classifying conductors by their cross-sectional area and resistance. Aluminium conductors have higher resistance – roughly 1
Here is an extract for (Class 2, the most common for fixed power cables): Need to check a specific conductor size or resistance value
500 – 630 – 800 – 1000 – 1200 – 1600 – 2000 – 2500 You will never see a 30 mm² or 80 mm² conductor in a compliant cable. Stick to the list. The Most Important Table: Maximum Resistance The true heart of the standard is the maximum DC resistance at 20°C. This prevents manufacturers from using cheap, impure copper or undersized strands.
0.5 – 0.75 – 1 – 1.5 – 2.5 – 4 – 6 – 10