CEI EN 60695-11-20 PDF

This part of IEC 60695 describes a test method consisting of two small-scale laboratory test procedures which is intended to compare the burning behaviour of different materials used in electrotechnical products. Vertically oriented bar specimens or horizontally oriented plate test specimens are exposed to a small flame ignition source with a nominal thermal power of 500 W. The test method uses two test specimen configurations to classify material performance. Rectangular bar-shaped test specimens are used to assess ignitability and burning behaviour, and square plate test specimens are used to assess the resistance of the test specimen to burn-through, as defined in 8.3.3. This test method only applies to materials that have been classified as V-0 or V-1 according to IEC 60695-11-10.

This test method is only applicable to solid and cellular materials that have an apparent density of more than 250 kg/m³, determined in accordance with ISO 845. The method does not apply to materials that shrink away from the applied flame without igniting due to their thinness.

The test method described provides classifications which may be used for quality assurance, the pre-selection of component materials of products, or to verify the required minimum flammability classification of materials used in end products. If used for pre-selection, then positive results shall be obtained at a test specimen thickness which equals the smallest thickness used in the product application.

The results obtained provide some information about the behaviour of materials in service, but cannot by themselves assure safe performance in service.

NOTE 1 Guidance on pre-selection is given in IEC 60695-1-30 [3]¹.

NOTE 2 Test results are influenced by material additives, e.g. pigments, fillers, and fire retardants, and properties such as the direction of anisotropy and the molecular mass.

This basic safety publication is intended for use by technical committees in the preparation of standards in accordance with the principles laid down in IEC Guide 104 and ISO/IEC Guide 51.

One of the responsibilities of a technical committee is, wherever applicable, to make use of basic safety publications in the preparation of its publications. The requirements, test methods or test conditions of this basic safety publication will not apply unless specifically referred to or included in the relevant publications.

¹ Numbers in square brackets refer to the bibliography.