What is IEC 60332-3-21- Test for vertical flame spread about?
IEC 60332-3-21 series covers category A F/R for methods of test for the assessment of the vertical flame spread of vertically mounted bunched wires or cables, under defined conditions.
IEC 60332-3-21 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 a 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.
Who is IEC 60332-3-21- Test for vertical flame spread for?
IEC 60332‑3‑21 on test on electric and optical fibre cables under fire conditions is useful for:
- Technicians and electricians
- Manufacturing unit of electric cables
- Quality assurance team
Why should you use IEC 60332-3-21- Test for vertical flame spread?
IEC 60332-3-21 defines the various categories and the relevant procedures. The categories are distinguished by test duration, the volume of non-metallic material of the test sample and the method of mounting the sample for the test. In all categories, cables having at least one conductor of cross-sectional area greater than 35 mm2 are tested in a spaced configuration, whereas cables of conductor cross-sectional area of 35 mm2 or smaller and optical fibre cables are tested in a touching configuration.
IEC 60332‑3‑21 series specify methods of test for flame spread characteristics for a single vertical insulated wire or cable.
IEC 60332‑3‑21 also covers the cable features as mentioned below:
- The volume of combustible material exposed to the fire and to any flame which may be produced by the combustion of the cables
- The geometrical configuration of the cables and their relationship to an enclosure
- The temperature at which it is possible to ignite the gases emitted from the cables
- The quantity of combustible gas released from the cables for a given temperature rise
- The volume of air passing through the cable installation
- The construction of the cable, for example, armoured or unarmoured, multi-, or single core.
IEC 60332-3-10 best practice guidelines help increase safety of optic fibres and cables.
What’s changed since the last update?
BS EN IEC 60332-3-21 supersedes BS EN 60332-3-21:2009. BS EN IEC 60332-3-21 includes some technical changes concerning BS EN 60332-3-21:2009. These include:
- Adjustments have been made to the title, and elsewhere, to emphasise the standard applies to optical fibre cables as well as metallic conductor types
- Details of how cables are mounted on the ladder have been better defined to improve repeatability and reproducibility.