电气火灾的原因和危害性我国的电气火灾大部分都是因漏电和短路而引发的，在低压配电系统中， 电气线路的漏电和短路是导致电气火灾发生的根源和重要原因之一， 并对国家经济和人民生命财产构成了很大的威胁，应引起大家高度的警惕和重视。 Electrical fire causes and harmfulness of the electrical fires were mostly caused by the leakage and the short circuit, in the low-voltage distribution system, leakage of electric circuit and short circuit is the root cause of electrical fires and one of the important reasons, and the national economy and people's life and property constitutes the great threat, should cause everyone to a high degree of attention and vigilance. 　　当电气线路和电气设备的绝缘受到损伤而导致接地故障，主要是指相线对地或与地有联系的导电体之间的短路，包括相线与大地、PE 线、PEN 线、配电和用电设备的金属外壳、敷线钢管、桥架线槽、建筑物金属构件、上下水和采暖、通风等管道以及金属屋面、水面等之间的短路。当发生接地短路时在接地故障持续的时间内， 与它有关联的电气设备和管道的外露可导电部分对地和装置外的可导电部分间存在故障电压。 When the insulation of the electrical circuits and electrical equipment damage caused by ground fault, is mainly refers to phase line to ground or are associated with the short circuit between the conductive body, including the line with the earth, PE line and PEN line, distribution and metal casing of electrical equipment, apply the wiring groove line pipe, bridge, building hardware, plumbing and heating, ventilation and other short circuit between pipe and metal roofing, surface, etc. When grounding short circuit occurs within the duration of the ground fault, it linked with electrical equipment and the pipeline can be exposed conductive parts to ground and device can be conductive part between the breakdown voltage. 　　此电压可使人身遭受电击， 也可因对地的电弧或火花引起火灾或爆炸，造成严重的经济和生命财产损失。 This voltage may cause an electric shock to the person, or a fire or explosion caused by an electric arc or spark in the ground, causing serious economic and loss of life and property.