Tests on electric and optical fibre cables under fire conditions—Part 33：Test for vertical flame spread of vertically-mounted bunched wires or cables—Category A
Tests on electric and optical fibre cables under fire conditions—Part 33: Test for vertical flame spread of vertically-mounted bunched wires or cables—Category A
1 Scope
This document covers test methods of category A for the assessment of vertical flame spread inhibition ability of vertically-mounted bunched wires or cables, or optical fibre cables, under defined conditions.
This document relates to electric or optical fibre cable test pieces mounted on the test steel ladder to achieve a nominal total volume of non-metallic material of 7 L/m. The flame application time is 40 min. Electric and optical fibre cables are mounted in the front of the ladder, with a standard or wide ladder being used for electric cables having a conductor with the cross-section greater than 35 mm2 according to the number of test pieces required, and a standard ladder for cables having a conductor with the cross-section of 35 mm2 and smaller. The category A is intended for general use where high volumes of non-metallic material are required to be evaluated.
The test is intended for type approval testing. The requirements for the selection of electric and optical fibre cables for testing are given in Annex A. The flame spread is measured as the extent of damage of the electric and optical fibre cable test sample. This procedure may be used to demonstrate the electric and optical fibre 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 "wire or cable" covers all insulated metallic conductor cables used for the conveyance of energy or signals.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60332-3-10 Tests on electric and optical fibre cables under fire conditions—Part 3-10: Test for vertical flame spread of vertically-mounted bunched wires or cables—Apparatus
Note: GB/T 18380.31-2022 Tests on electric and optical fibre cables under fire conditions—Part 31: Test for vertical flame spread of vertically-mounted bunched wires or cables—Apparatus (IEC 60332-3-10: 2018, IDT)
IEC 60811-606 Electric and optical fibre cables—Test methods for non-metallic materials—Part 606: Physical tests—Methods for determining the density
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
ignition source
source of energy that initiates combustion
[Source: ISO 13943: 2017, 3.219]
3.2
char
carbonaceous residue resulting from pyrolysis or incomplete combustion
[Source: ISO 13943: 2017, 3.47]
3.3
flame spread
propagation of a flame front
[Source: ISO 13943: 2017, 3.168]
4 Test apparatus
4.1 General
The apparatus specified in IEC 60332-3-10 shall be used.
4.2 Ignition source
The ignition source shall be one or two ribbon-type propane gas burners as specified in IEC 60332-3-10.
A single burner shall be used with the standard ladder and two burners with the wide ladder.
5 Test procedure
5.1 Test sample
The test sample shall comprise a number of test pieces of the electric and optical fibre cable with the same length, each having a minimum length of 3.5m.
The total number of test pieces shall be that number required to provide a nominal total volume of non-metallic material of 7 L/m of test sample.
The test sample shall be selected within the range specified in Annex A.
The electric or optical fibre cable test pieces forming the test sample shall be conditioned at a temperature of (20 ± 10)°C for at least 16h before commencing the test. The test pieces shall be dry.
5.2 Determination of the number of test pieces
In order to calculate the appropriate number of test pieces, it is necessary to determine the volume per meter of non-metallic material of one test piece.
A length of electric and optical fibre cable which shall be not less than 0.3m long is carefully cut to ensure that the surfaces are at right angles to the cable axis, thus enabling precise measurements of its length.
The density of each non-metallic material (including cellular material) shall be measured in an appropriate way, for example according to IEC 60811-606, in order to obtain values expressed to the second decimal place.
Each non-metallic material Ci shall be removed from the test piece and weighed. Any non-metallic material making up less than 5% of the total non-metallic mass of the test piece shall be assumed to have a density of 1 kg/dm3.
Where semi-conducting screens cannot be removed from the insulating material, the components may be considered as one for the purpose of measuring their mass and density.
The volume Vi (L/m) of each non-metallic material Ci is calculated as follows:
where,
Mi——the mass of the material Ci, kg;
ρi——the density of the material Ci, kg/dm3;
l——the length of the test piece of the electric and optical fibre cable, m.
The total volume, V, of the non-metallic materials contained in per meter of electric and optical fibre cable is equal to the sum of the individual volumes V1, V2, etc.
The number of test pieces to be mounted is obtained by taking the closest integer (0.5 and above corresponding to 1) of the ratio of the volume per meter specified in 5.1 and the total volume, V, of non-metallic material per meter of cable, subject to a minimum number of two test pieces.
Foreword i Introduction iii 1 Scope 2 Normative references 3 Terms and definitions 4 Test apparatus 5 Test procedure 6 Evaluation of test results 7 Performance requirements 8 Retest procedure 9 Test report Annex A (Normative) Guidance on electric and optical fibre cable selection for type approval testing Annex B (Informative) Recommended performance requirements Bibliography
电缆和光缆在火焰条件下的燃烧试验 第33部分：垂直安装的成束电线电缆 火焰垂直蔓延试验 A类 1 范围 本文件描述了A类试验方法，用来评价垂直安装的成束电线电缆或光缆在规定条件下抑制火焰垂直蔓延的能力。 本文件适用于安装在试验钢梯上的电缆或光缆试样段所含非金属材料的标称体积总量为7L/m。供火时间为40min。电缆和光缆安装在钢梯前面，导体截面大于35mm2的电缆根据电缆试样段数量选择标准钢梯或宽型钢梯，导体截面35mm2及以下的电缆和光缆使用标准钢梯。A类用于评定高非金属材料体积含量的场合。 本试验用于型式认可试验。试验用电缆和光缆的选择要求见附录A。火焰蔓延通过电缆和光缆试样的损坏范围来测定。本试验程序可用于验证电缆和光缆抑制火焰蔓延的能力。 附录B中给出了推荐的性能要求。 注：本文件中术语“电线电缆”包括所有用于电能或信号传输的金属导体绝缘电缆。 2 规范性引用文件 下列文件中的内容通过文中的规范性引用而构成本文件必不可少的条款。其中，注日期的引用文件，仅该日期对应的版本适用于本文件；不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。 IEC 60332-3-10 电缆和光缆在火焰条件下的燃烧试验 第3-10部分：垂直安装的成束电线电缆火焰垂直蔓延试验试验装置(Tests on electric and optical fibre cables under fire conditions—Part 3-10：Test for vertical flame spread of vertically mounted bunched wires or cables—Apparatus) 注：GB/T 18380.31—2022 电缆和光缆在火焰条件下的燃烧试验 第31部分：垂直安装的成東电线电缆火焰垂直蔓延试验试验装置(IEC 60332-3-10：2018，IDT) IEC 60811-606 电缆和光缆 非金属材料测试方法 第606部分：理化试验 密度测量方法(Eletric and optical fibre cables—Test methods for non-metallic materials—Part 606：Physical tests—Methods for determining the density) 3 术语和定义 下列术语和定义适用于本文件。 3.1 引燃源 ignition source 引发燃烧的能量源。 [来源：ISO 13943：2017，3.219] 3.2 炭 char 因热解或不完全燃烧产生的碳残余物。 [来源：ISO 13943：2017，3.47] 3.3 火焰蔓延 flame spread 火焰前沿的传播。 [来源：ISO 13943：2017，3.168] 4 试验装置 4.1 通则 应使用IEC 60332-3-10中规定的设备。 4.2 引燃源 引燃源应采用IEC 60332-3-10中规定的一个或两个带型丙烷气体燃烧器。 标准钢梯应采用一个燃烧器，宽型钢梯采用两个燃烧器。 5 试验步骤 5.1 试样 试样应由若干根等长的电缆和光缆试样段组成，每根试样段的最小长度为3.5m。 试样段的总数应满足所有电缆和光缆试样段所含非金属材料标称体积总量为7L/m。 试样应在附录A规定的范围内进行选择。 试验前作为试样的电缆和光缆试样段应在(20±10)℃下放置至少16h。试样段应是干燥的。 5.2 试样段数量的确定 为计算试样段的数量，应确定一根试样段每米所含非金属材料的体积。 应仔细截取一根不小于0.3m的电缆和光缆，其截面与电缆和光缆的轴线成直角，以便能精确测量其长度。 每种非金属材料(包括发泡材料)的密度应采用适当方法测量，例如IEC 60811-606，测得的数据保留到小数点后第2位。 应剥下电缆和光缆上的每种非金属材料Ci并称重。任何小于非金属材料总质量5％的材料应假定其密度为1 kg/dm3。 如果半导电屏蔽不能从绝缘材料上剥离，可以将两者视为一体测量质量和密度。 每种非金属材料Ci的体积Vi(L/m)按下式计算：
*IEC 60332-3-10 Tests on electric and optical fibre cables under fire conditions-Part 3-10: Test for vertical flame spread of vertically-mounted bunched wires or cables-Apparatus *Note:GBT- *IEC 60811-606 Electric and optical fibre cables-Test methods for non-metallic materials-Part 606: Physical tests-Methods for determining the density
