DIN EN 60332-3-21:2010-08

The series of International Standards, covered by the Parts 3-10, 3-21, 3-22, 3-23, 3-24, and 3-25 of IEC 60332, specifies test methods for the assessment of flame spread of vertically-mounted bunched wires or cables, electrical or optical, under defined conditions. Part 3 of IEC 60332 describes in detail a test where a number of cables or wires are bundled together in order to simulate various test installations. Taking into account an easier application of the apparatus and the various categories, the titles of the parts are as follows: Part 3-10 Apparatus Part 3-21 Category A F/R Part 3-22 Category A Part 3-23 Category B Part 3-24 Category C Part 3-25 Category D Part 3-10 specifies the apparatus, its arrangement and calibration. Starting with Part 3-21, the parts define the various categories and associated tests. The categories are differentiated by the test duration, the volume of non-metallic materials of the samples and the method of their attachment during the test. All categories are tested, whereby the cables or wires having at least one conductor with a nominal cross-section of more than 35 mm² are tested leaving a distance between them, whereas cables or wires with conductor nominal cross-sections of 35 mm² or less are tested in a configuration where the samples are in contact with each other. The categories are not directly related to certain protection levels of specific cable or wire installations. The real installation of the cables or wires installed may be, however, a certain factor for flame spread in an actual case of fire. The attachment method described as category A F/R (Part 3-21) is intended for special types of cable and wire, which are used for particular installations. The categories A, B, C and D (Part 3-22 to 3-25, respectively) are intended for general applications, where different volumes of non-metallic materials are available. The responsible Committee is Subcommittee UK 411.2 "Isolierte Starkstromleitungen" ("Insulated cables, wires and flexible cords for power installation") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.