Calculation of the effective parameters of magnetic piece parts

IEC 60205:2026 CMV contains both the official standard and its commented version. The commented version provides you with a quick and easy way to compare all the changes between IEC 60205:2026 edition 5.0 and the previous IEC 60205:2016 edition 4.0. Furthermore, comments from IEC TC 51 experts are provided to explain the reasons of the most relevant changes, or to clarify any part of the content.

IEC 60205:2026 specifies uniform rules for the calculation of the effective parameters of closed circuits of ferromagnetic material.

This edition includes the following significant technical changes with respect to the previous edition:

a) addition, in 5.1, of the drawing and the formulae of pair of URS-cores of rectangular-circular section;

b) using, in 5.9, 5.10, 5.11 and 5.13, the conventional calculation formula that includes "B1？D" is limited for the x-x cores (x is EL, ER, PQ or E) and addition new formulae for x？PLT cores that replaces "B1-D" with "(B1-D+B2)/2";

c) addition, in 5.9, 5.10, 5.11 and 5.13, of formulae of l1 and l3 for x-PLT cores (x is EL, ER, PQ or E) which is different from the l1 and l3 of x-x cores;

d) addition of formula Amin in each subclause from 5.2.1 to