IEC 63093-11:2018

Overview - IEC 63093-11:2018 (Ferrite cores - EC‑cores for power supplies)

IEC 63093-11:2018 is an International Electrotechnical Commission standard that specifies mechanical dimensions, effective magnetic parameters, and allowable surface irregularities for a preferred range of EC‑cores made of ferrite used in power‑supply applications. It ensures mechanical interchangeability of complete core assemblies and coil formers and provides practical guidance for negotiations between ferrite core manufacturers and customers. This edition integrates and replaces IEC 62317‑11:2015 and IEC 60424‑3:2015.

Key topics and technical requirements

• Principal dimensions and tolerances: Defines the essential geometric dimensions for EC‑core sizes (EC 35 through EC 120) to ensure mechanical interchangeability of cores and coil formers.
• Effective parameters (Amin, leakage, volumes): Provides effective parameter values to be used in calculations (see IEC 60205 for parameter definitions and calculation methods). Manufacturers may publish more precise values in catalogues.
• Coil former limits: Specifies essential dimensional limits for compatible coil formers and includes example coil former designs (Annex A).
• Surface irregularities and visual acceptance criteria: Gives definitions and limits for common defects - chips, ragged edges, cracks, flash, pull‑outs, crystallites and pores:
  • Minimum visually distinguishable chip area is 0.5 mm², maximum allowable single area 25 mm².
  • For chips on mating surfaces: cumulative chip area must be < 6% of the mating surface area; total length of ragged edges < 25% of the surface perimeter.
  • Illustrative figures, inspection references and tables for crack limits and pore locations are included.
• Annexes: Annex A provides coil former examples; Annex B (informative) contains allowable areas of chips.

Practical applications - who uses this standard

• Ferrite core manufacturers - to design and certify EC‑cores and produce consistent dimensional data and visual acceptance criteria.
• Power supply designers and magnetic component engineers - to select interchangeable EC‑cores, specify coil formers and use the effective parameters in electromagnetic calculations.
• Quality assurance and procurement teams - to define acceptance criteria, perform visual inspections, and negotiate supply contracts based on standardized limits for surface irregularities.
• Test labs and certification bodies - to verify compliance with dimensional and surface defect limits.

Related standards and references

• IEC 60205 - Calculation of effective parameters of magnetic piece parts (parameter definitions and methods).
• IEC 60401‑1 - Terms and nomenclature for ferrite cores (physical irregularities).
• IEC 60424‑1 - General specification for limits of surface irregularities.

Keywords: IEC 63093‑11:2018, EC‑cores, ferrite cores, power supply applications, surface irregularities, dimensions, coil formers, effective parameters, mechanical interchangeability.