This part of IEC 63093 specifies the dimensions that are of importance for mechanical interchangeability for a preferred range of EP-cores made of ferrite, the essential dimensions of coil formers to be used with them and the locations of their terminal pins on a 2,50 mm printed wiring grid in relation to the base outlines of the cores and the effective parameter values to be used in calculations involving them. It also gives guidelines on allowable limits of surface irregularities applicable to EP-cores.
The specifications contained in this document are useful in negotiations between ferrite core manufacturers and users about surface irregularities.
The general considerations upon which the design of this range of cores is based are as given in Annex A.