OSI 2678 International Standard INTE RNATIONAL ORGANIZATION'FOR STANDARDIZATION MEKAYHAPOAHAR OPTAHW3AUWA NO CTAHAAPTW3AWW·ORGANISATION INTE RNATIONALE DE NORMALISATION Environmental tests for aircraft equipment Insulation resistance and high voltage tests for electrical equipment Essais en environnement pour les equipements aeronautiques - Essais de resistance d'isolement et de haute tension pour les équipements electriques Second edition - 1985-05-15 UDC 629.7.064.5 : 621.3.048 : 620.1 Ref. No. 1SO 2678-1985 (E) ISO 2678-1985 (E) Descriptors : aircraft, aircraft equipment, electrical equipment, tests, environmental tests, high voltage tests, insulation resistance. Price based on 3 pages Copyright International Organization for Standardization Not for Resale Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (iso member bodies). The work of preparing International Standards is normally carried out through ISso technical committees. Each member the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with IsO, aiso take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with ISO procedures requiring at International Standard ISO 2678 was prepared by Technical Committee iSO/TC 20, Aircraft and space vehicles. IS0 2678 was first published in 1977. This second edition cancels and replaces the first edition, of which it constitutes a minor revision. The main changes are the following : title : deletion of "Part 4.3"; clause 0 : insertion of sub-clause 0.1; ciause 2 : replacement of the reference to 1S0 2650 with the reference to ISo 7137 [and corresponding change to footnote 1) in table 2]. @ International Organization for Standardization, 1985 Printed in Switzerland Copyright International Organization for Standardization Not for Resale ISO 2678-1985 (E) INTERNATIONAL STANDARD Environmental tests for aircraft equipment - Insulation resistance and high voltage tests for electrical equipment O Introduction 0.2.3 Purpose of leakage current measurements 0.1 This nternational Standard is part of a series of stan- semi-conductors are used. The test voltage is dependent on the dards, specifying environmental tests for aircraft equipment, rated voltage of the component. and details of which are given in fSO 7137. 1 Scope and field of application 0.2 The operational safety of electrical equipment for aircraft This International Standard specifies requirements for tests to requires a good quality of insulation and the avoidance of ex- determine the electrical insulation resistance of equipment in- cess voltages. Dimensions and quality of the insulation have to tended for use in aircraft, together with a high voitage test. It be suitable for the operating voltages and the effects of climatic relates the insulation requirements to four categories of equip- conditionsencountered,suchastemperature,humidity,at ment. mospheric pressure and surface contamination. The trend towards smaller and safer designs can only be realized if the This international Standard does not deal with the insulation physical properties and the behaviour of the insulation are testing of equipment installed in aircraft. known and proven by accurate test procedures. Reference 2 Insulation resistance measurements and high voltage testing have to be considered as two different tests. A high insulation ISo 7137, Aircraft - Environmental conditions and test pro- cedures for airborne equipment. 1) defects : cracks, for instance, may exist, provoking voltage flash-overs. 3 Definitions For the purposes of this International Standard, the following 0.2.1 Purpose of high voltage test definitions apply. The high voltage test serves to prove the capability of