●建筑物内的导线使用年久失修，其绝缘层老化破损。
The conductors in buildings are out of repair for a long time, and their insulation layer is aging and damaged.
●建筑物内导线安装施工不规范，如导线不穿阻燃管，直接埋于墙内或置于桁架上。
Installation and construction of conductors in buildings are not standardized, such as conductors without flame retardant tubes, directly buried in walls or placed on trusses.
●导线施工质量粗糙，偷工减料，使用钢管穿线时钢管内壁刮伤导线绝缘层。
Conductor construction quality is rough, Jerry work and material reduction. When using steel pipe to thread, the inner wall of steel pipe scratches the insulating layer of conductor.
●娱乐场所等公共活动场所在进行二次装修时，乱敷电线，致使各种施工遗留缺隐贴近易燃物；
During the second decoration of public places of activity such as entertainment places, wiring is laid indiscriminately, resulting in various kinds of construction remains close to flammable materials.
●电气设计不当，包括使用者随意增加负荷钢制闸门 钢坝 保定轻钢别墅 保定平面设计培训 保定室内设计培训 保定办公家具 保定空调维修 ，造成导线过负荷而发热，导线绝缘层老化失效。
Improper electrical design, including user's arbitrary increase of load, resulting in overload and heating of conductors, aging and failure of insulating layer of conductors.
●用户内部私拉乱扯线路，架设极不规范。
Private pulling of lines within users is extremely irregular.
●线路受自然条件影响，如导线碰树，大风吹断导线，空气潮湿导致导线绝缘水平下降等。
Circuits are affected by natural conditions, such as wire hitting trees, wind breaking conductors, air humidity leading to the decline of conductor insulation level, etc.
●各种人为的破坏造成断线等。
Various kinds of man-made destruction caused wire breakage and so on