• Objective
Test for the assessment of vertical flame spread of vertically - mounted bunched wires or cables ,electrical or optical , under defined conditions.
• Reference Standard
IEC 60332-3 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
Part 3-22: Test for vertical flame spread of vertically-mounted bunched wires or cables - Category A
Part 3-23: Test for vertical flame spread of vertically-mounted bunched wires or cables - Category B
Part 3-24: Test for vertical flame spread of vertically-mounted bunched wires or cables - Category C
Part 3-25: Test for vertical flame spread of vertically-mounted bunched wires or cables - Category D
• Test Detail
The test comprises of 5 categories.
| Category |
A
F/R |
A |
B |
C |
D |
| Total volume of non-metallic material (l/m) |
7 |
7 |
3.5 |
1.5 |
0.5 |
| Flame application time |
40 |
40 |
40 |
20 |
20 |
The samples which have minimum length of 3.5 m shall be attached to vertical ladder and shall be conditioned at a temperature of 20 ± 10° C for at test 16 h before commence the test. The test flame with a nominal heat 70,000 ± 1,600 Btu/h shall be applied to samples according to the selected category. After burning or glowing has ceased or been extinguished, the samples are wiped clean to find the onset of char by press against the cable surface with a sharp object. Where the surface changes from a resilient to a brittle(crumbling) surface, this indicate the onset of char.
• Performance Requirement
The maximum extent of the charred portion measured on the sample shall not have reached a height exceeding 2.5 m above the bottom edge of the burner.
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