IEC 60332-3-21 Tests on electric cables under fire conditions –Part 3-21:Test for vertical flame spread of vertically-mounted bunched wires or cables – Category A F/R

1 Scope
The series of International Standards covered by Parts 3-10, 3-21, 3-22, 3-23, 3-24 and 3-25 of IEC 60332 specifies methods of test for the assessment of vertical flame spread of verticallymounted
bunched wires or cables, electrical or optical, under defined conditions.

NOTE For the purpose of this standard the term “electric wire or cable” covers all insulated metallic conductor cables used for the conveyance of energy or signals.

The test is intended for type approval testing. The requirements for the selection of cables fortesting are given in annex A. The flame spread is measured as the extent of damage of the
cable sample. This procedure may be used to demonstrate the cable’s ability to limit flamespread.

This part of IEC 60332 covers category A F/R and 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.
A recommended performance requirement is given in annex B.

2 Normative references

The following normative documents contain provisions which, through reference in this text,constitute provisions of this part of IEC 60332. For dated references, subsequent amendments
to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of IEC 60332 are encouraged to investigate the possibility of applying the
most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain
registers of currently valid International Standards.

IEC 60332-3-10:Tests on electric cables under fire conditions – Part 3-10: Test for vertical flame spread of vertically-mounted bunched wires or cables – Apparatus
IEC 60695-4: Fire hazard testing – Part 4: Terminology concerning fire tests
IEC 60811-1-3: Insulating and sheathing materials of electric cables – Common test methods Part 1: General application – Section 3: Methods for determining the density – Water
absorption tests – Shrinkage test
IEC Guide 104: The preparation of safety publications and the use of basic safety publications and group safety publications