Tests on electric and optical fibre cables under fire conditions - Part 3-21: Test for vertical flame spread of vertically-mounted bunched wires or cables - Category A F/R
CENELEC - European Committee for Electrotechnical Standardization
适用范围
"This part of IEC 60332 covers category A F/R for methods of test for the assessment of vertical flame spread of vertically-mounted bunched wires or cables@ under defined conditions. This document relates only to power cables of conductor cross-sectional area greater than 35 mm2 installed on the test ladder in a spaced configuration on the front and rear to achieve a nominal total volume of non-metallic material of 7 l/m of test sample. The flame application time is 40 min. This method of mounting is intended for special cable designs used in particular installations when required in the cable specification. Category A F/R is not intended for general use. The test is intended for type approval testing. The requirements for the selection of cables for testing are given in Annex A. The flame spread is measured as the extent of damage of the cable sample. This procedure can be used to demonstrate the cable??s ability to limit flame spread. A recommended performance requirement is given in Annex B. NOTE For the purposes of this document the term ""electric wire or cable"" covers all insulated metallic conductor cables used for the conveyance of energy or signals."