闸刀开关过载火灾危险性研究

A Fire Risk Analysis of Knife Switch in Case of Overload

通过实验研究了不同类型的闸刀开关在不同过负荷电流条件下的温度上升情况,测量了闸刀开关在两类过负荷条件下的最高温度以及达到最高温度需要的时间,并对影响闸刀开关温度升高的因素以及达到最高温度时能否引燃周围可燃物进行了分析讨论。实验结果显示,闸刀开关在Ⅱ类过负荷条件下的火灾危险性远大于在Ⅰ类过负荷条件下的火灾危险性。在同类过负荷电流条件下,闸刀开关的额定电流越大,过负荷倍数越大,火灾危险性也越大。

When the knife switch overloaded, temperatures of switch leads, the meet place of dynamic and static slices, and the fuse will rise, which might light surrounding burnable materials and causing fire. In order to fully tell the possibility of fire caused by overloading knife switch and factors that affecting temperature rising of the knife switch. Two knifes were studied in different overload pattern. The max temperature of the knife switch reached and the time needed to reach the max temperature were measured. The result shows that the second overload condition has bigger fire risk than the first overload condition. When the knife switch under same overload condition, the rated current and overload times play an important role in temperature rise, more rated current and times overload, bigger fire risk.