Cable size calculator
The smallest section of a 0.6/1 kV cable that carries a load, by IEC 60364-5-52:2009: the base current of the reference method times every correction factor, each with its table. Free; the cable designer does the same for any design and adds the voltage drop.
The method
Reference methods, Table B.52.1: A1 and A2 in conduit in a thermally insulated wall, B1 and B2 in conduit on a wooden wall, C on a wooden wall, all in air at 30 °C (Table B.52.14) and grouped by Table B.52.17; D2 direct in the ground at 0.7 m, ground 20 °C, 2.5 K·m/W, with the direct buried row of Table B.52.16 and the grouping of Table B.52.18. Single-core cables read the 3 loaded conductors column.
Every section of the family was tried with the panel's installation and factors; the rating, rounded as shown, must be at least the load. With a length, the drop is checked as well.
Open the full calculation in the cable designer · Voltage drop calculator
Questions and answers
How do I choose the cable size for a load?
Find the reference method of the installation in IEC 60364-5-52 Table B.52.1, read the current of each section in its column, multiply it by the factors for the air or ground temperature, the soil and the grouping, and take the smallest section whose result is at least the load current. Then check the voltage drop.
What size of cable carries 100 A?
A four-core XLPE copper cable on a wall (method C) in air at 30 °C, alone: 25 mm², rated 119 A by IEC 60364-5-52:2009. Grouped, buried or hotter, the section grows; the calculator above shows each case.
Which standard gives the current ratings?
Reference methods, Table B.52.1: A1 and A2 in conduit in a thermally insulated wall, B1 and B2 in conduit on a wooden wall, C on a wooden wall, all in air at 30 °C (Table B.52.14) and grouped by Table B.52.17; D2 direct in the ground at 0.7 m, ground 20 °C, 2.5 K·m/W, with the direct buried row of Table B.52.16 and the grouping of Table B.52.18. Single-core cables read the 3 loaded conductors column.