• IEC 61125:2018

    Current The latest, up-to-date edition.

    Insulating liquids - Test methods for oxidation stability - Test method for evaluating the oxidation stability of insulating liquids in the delivered state

    Available format(s):  Hardcopy, PDF, PDF 3 Users, PDF 5 Users, PDF 9 Users

    Language(s):  English - French, Spanish, Castilian

    Published date:  12-01-2018

    Publisher:  International Electrotechnical Committee

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    Table of Contents - (Show below) - (Hide below)

    1 Scope
    2 Normative references
    3 Terms and definitions
    4 Apparatus
    Annex A (normative) - Thermometer specifications
    Annex B (informative) - Method for evaluating the
            oxidation stability of inhibited insulating
            liquids in the delivery state by measurement
            of the induction period with oxygen
    Annex C (informative) - Method for evaluation of
            thermo-oxidative behaviour of unused
            ester insulating liquids

    Abstract - (Show below) - (Hide below)

    IEC 61125:2018 describes a test method for evaluating the oxidation stability of insulating liquids in the delivered state under accelerated conditions regardless of whether or not antioxidant additives are present. The duration of the test can be different depending on the insulating liquid type and is defined in the corresponding standards (e.g. in IEC 60296, IEC 61099, IEC 62770). The method can be used for measuring the induction period, the test being continued until the volatile acidity significantly exceeds 0,10 mg KOH/g in the case of mineral oils. This value can be significantly higher in the case of ester liquids.
    Additional test methods such as those described in IEC TR 62036 based on differential scanning calorimetry can also be used as screening tests, but are out of the scope of this document.
    This second edition cancels and replaces the first edition published in 1992 and Amendment 1: 2004. This edition constitutes a technical revision.
    This edition includes the following significant technical changes with respect to the previous edition:
    a) the title has been modified to include insulating liquids different from mineral insulating oils (hydrocarbon);
    b) the method applies for insulating liquids in the delivered state;
    c) former Method C is now the main normative method;
    d) precision data of the main normative method has been updated concerning the dissipation factor;
    e) former Method A has been deleted;
    f) former Method B has been transferred to Annex B;
    g) a new method evaluating the thermo-oxidative behaviour of esters is included in Annex C.

    General Product Information - (Show below) - (Hide below)

    Committee TC 10
    Development Note Supersedes IEC 60074, IEC 60474, IEC 60813 (03/2001) Stability Date: 2023. (01/2018)
    Document Type Standard
    Publisher International Electrotechnical Committee
    Status Current

    Standards Referencing This Book - (Show below) - (Hide below)

    ISO 4793:1980 Laboratory sintered (fritted) filters — Porosity grading, classification and designation
    IEC 62021-1:2003 Insulating liquids - Determination of acidity - Part 1: Automatic potentiometric titration
    IEC TR 62036:2007 Mineral insulating oils - Oxidation stability test method based on differential scanning calorimetry (DSC)
    IEC 62021-2:2007 Insulating liquids - Determination of acidity - Part 2: Colourimetric titration
    IEC 60422:2013 Mineral insulating oils in electrical equipment - Supervision and maintenance guidance
    IEC 60050-212:2010 International Electrotechnical Vocabulary (IEV) - Part 212: Electrical insulating solids, liquids and gases
    ISO 383:1976 Laboratory glassware — Interchangeable conical ground joints
    IEC 62770:2013 Fluids for electrotechnical applications - Unused natural esters for transformers and similar electrical equipment
    IEC 61099:2010 Insulating liquids - Specifications for unused synthetic organic esters for electrical purposes
    IEC 60296:2012 RLV Fluids for electrotechnical applications - Unused mineral insulating oils for transformers and switchgear
    IEC 60666:2010 Detection and determination of specified additives in mineral insulating oils
    ISO 6344-1:1998 Coated abrasives Grain size analysis Part 1: Grain size distribution test
    IEC 60247:2004 Insulating liquids - Measurement of relative permittivity, dielectric dissipation factor (tan d) and d.c. resistivity
    IEC 62021-3:2014 Insulating liquids - Determination of acidity - Part 3: Test methods for non-mineral insulating oils
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