EN 61144 EUROPEAN STANDARD NORME EUROPEENNE February 1993 EUROPAISCHE NORM UDC 621.315:620.1:546.21 Descriptors: Electrical insulating materials, liquid electrical insulating materials, fire tests, flammability, combustion, measurements oxygen index English version Test method for the determination of oxygen index of insulating liquids (IEC 1144:1992) Méthode d'essai pour la détermination de MeBverfahren zur Bestimmung des I'indice d'oxygene des isolants liquides Sauerstoff-Kennwertes von (CEI 1144:1992) Isolierflussigkeiten (IEC 1144:1992) This European Standard was approved byCENELEC on1992-12-09. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europaisches Komitee fur Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels C 1993 Copyright reserved to CENELEC members Ref.No.EN61144:1993E EN 61144:1993 Contents Foreword Page The text of document 10(CO)264, as prepared by IECTechnicalCommitteeNo.10:Fluidsfor Foreword 2 electrotechnical applications was submitted to the Introduction 3 IEC-CENELEC parallel vote in March 1992. Scope 1 3 The reference document was approved by 2 Normative reference 3 CENELEC as EN 61144 on 9 December 1992. 3 Definition 3 The following dates were fixed: 4 Summary of method 3 latest date of publication 5 Apparatus 3 of an identical national standard (dop) 1993-12-01 6 Test specimens 4 7 latest date of withdrawal Procedure 4 of conflicting national 8 Calculations 4 standards (dow) 1993-12-01 9 Report 5 Precision 5 10 Figure 1 - Schematic arrangement of apparatus for determination of oxygen index 6 Borosilicate glass test cup Figure 2 一 for determination of oxygen index of 7 liquids Figure 3-Ignition system for determination of oxygen index of liquids 80 2 EN 61144:1993 Introduction 3 Definition IEC Technical Committee 89 has been issuing Oxygen index is defined in IS0 4589 as the guidelines for the evaluation of the fire hazard minimum concentration of oxygen, by percentage associated with electrical equipment and solid volume in a mixture of oxygen and nitrogen, electrical insulation. introduced at 23 °C ± 2 °C, that will just support combustion of a material under specified test In IEC 695-1-1 it is stated that the following conditions. properties are relevant to the full assessment of fire hazard: 4 Summary of method -ignitability; A small quantity of a liquid sample in a borosilicate - combustion; glass cup is placed in a test chimney containing an propagation; upwardly flowing mixture of oxygen and nitrogen, opacity, toxicity and corrosiveness of smoke then ignited. The minimum concentration of oxygen and gaseous products of combustion. that will just support combustion of the liquid IEC TC 10 has planned to develop standard method for 60 s or more is taken as the oxygen index. of test covering each of the above properties for 5 Apparatus electrical insulating liquid. This publication contains a standard method for the The following apparatus shall be arranged as measurement of the oxygen index, a property which indicated