IEC 60938-2 pdf download

IEC 60938-2 pdf download.Fixed inductors for electromagnetic interference suppression – Part 2: Sectional specification on power line chokes
1 Scope
This part of IEC 60938 applies to fixed inductors designed for electromagnetic interference suppression, which will be connected to an AC mains or other supply with a nominal voltage not exceeding 1 000 V AC RMS or 1 500 V DC with a nominal frequency not exceeding 400 Hz. This sectional specification is restricted to fixed inductors for which safety tests are appropriate. This implies that inductors specified according to this specification will either be connected to mains supplies, when compliance with the mandatory tests of Annex A is necessary, or used in other circuit positions where the equipment specification prescribes that some or all of these safety tests are required. The object of this document is to prescribe standard requirements for safety tests, preferred ratings and characteristics, to select from IEC 60938-1 the appropriate methods of test and to give general performance requirements for suppression inductors.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60938-1 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp
4 General requirements
4.1 General Units, graphical symbols, letter symbols and terminology shall be taken from the following publications whenever possible: – IEC 60027 (all parts), – IEC 60050 (all parts), – IEC 6061 7, – ISO 80000-6. When further items are required, they shall be derived in accordance with the principles of the documents listed above. 4.2 Preferred values of ratings and characteristics 4.2.1 Climatic categories Electromagnetic interference suppression inductors covered by this specification are classified into climatic categories according to the general rules given in IEC 60068-1 . The lower and upper category temperatures and the duration of the damp heat, steady state test shall be selected from the following: Lower category temperature: −65 °C, −55 °C, −40 °C, −25 °C and −1 0 °C. Upper category temperature: +85 °C, +1 00 °C, +1 25 °C and +1 55 °C. Duration of the damp heat, steady state test: 21 days and 56 days. The severities for the cold and dry heat tests are the lower and upper category temperatures respectively. 4.2.2 Nominal inductance and tolerance Preferred values of nominal inductance are values chosen from the E6 series of preferred values given in IEC 60063. The preferred tolerances on inductance are as follows: ±30 %; −30 % / +50 % If not stated otherwise in the detail specification, a linear derating of applied current over ambient temperature is assumed up to zero current at the upper category temperature T C . 4.3 Information to be given in a detail specification 4.3.1 General Detail specifications shall be derived from the relevant blank detail specification. Detail specifications shall not specify requirements inferior to those of the generic or sectional specification. When more severe requirements are included, they shall be listed separately. 4.3.2 Outline drawing and dimensions There shall be an illustration of the inductor as an aid to easy recognition and for comparison of the inductor with others. Dimensions and their associated tolerances, which affect interchangeability and mounting, shall be indicated upon the drawing. All dimensions shall be stated in millimetres. The numerical values shall be given for the length of the body, the width and height of the body or for cylindrical types, the body diameter, and the length and diameter of the terminations. When necessary, for example when a number of items (inductance values/ voltage ranges) are covered by a detail specification, the dimensions and their associated tolerances shall be placed in a table below the drawing. When the configuration is other than described above, the detail specification shall state such dimensional information to describe the inductor adequately. When the inductor is not designed for use on printed boards, this shall be clearly stated in the detail specification.