着火条件下电缆和光缆的试验.第2-2部分:单根小型绝缘电线或电缆的垂直火焰蔓延试验.扩散火焰规程

[中文适用范围]： GB／T 18380的本部分规定了在火焰条件下，单根绝缘细电线电缆或细光缆火焰垂直蔓延试验的 方法。试验设备在GB／T 18380．21 2008中规定。 当GB／T 18380．12 2008规定的试验方法不适用，如在试验供火期间可能断裂的细光缆或导体可 能熔断的细电线。本标准建议在测试细光缆，总截面小于O．5 mm。的绝缘细电线电缆时采用。 注：使用符合本标准的绝缘电线电缆并不足以防止在所有敷设条件下的火焰蔓延。在一些危险性高的场合，如成 束电线大长度垂直敷设时，不能认为一根试样符合车标准的性能要求，而成束的该种电线亦会表现出同样的性 能(见GB，T 18380 3l～36系列标准)。 推荐的性能要求见附录A。 [外文原描述]： IEC 60332-2-2:2004 Specifies the procedure for testing the resistance to vertical flame propagation for a single small vertical electrical insulated conductor or cable, or optical cable, under fire conditions. The apparatus is given in IEC 60332-2-1. This standard gives the procedure for testing small optical fibre cables or a small insulated conductor or cable when the method specified in IEC 60332-1-2 is not suitable because some small optical fibre cables may break or small conductors may melt during the application of the flame. The recommended range of application is for the testing of small single insulated conductors or cables of less than 0,5 mm² cross-section. NOTE Since the use of insulated conductor or cable which retards flame propagation and complies with the recommended requirements of this standard is not sufficient by itself to prevent propagation of fire under all conditions of installation, it is recommended that wherever the risk of propagation is high, for example, in long vertical runs of bunches of cables, special installation precautions should also be taken. It cannot be assumed that because the sample of cable complies with the performance requirements recommended in this standard, that a bunch of cables will behave in a similar manner. (See IEC 60332-3 series.) Recommended requirements for performance are given in Annex A.