起重机械的接地方式和接地故障保护分析

Analysis on Grounding Method and Ground Fault Protection of Cranes

起重机械是一种特种设备,其安全受到极大重视,国家针对起重机械的设计、安装、使用等安全方面制订了相关标准。在起重机械接地方式和接地故障保护方面,标准缺少详细规定,行业内各单位对标准理解和掌握的尺度不一致,设计和施工不规范,导致现场使用的起重机械存在着人身触电和用电设备烧毁等安全隐患。参照相关标准和理论,通过分析比较不同电力系统的工作原理和接地短路计算,提出了起重机械的接地和接地故障保护是一项系统工程的观点,认为与起重机械关联的馈电系统、轨道、承轨梁、起重机械上的钢结构及其电气设备等的接地方式,以及接地故障保护开关型式等环节,唯一取决于电力系统的型式,并提供了各环节接地的规范做法和实施细则。有效解决了单相接地故障隐患,丰富补充了标准的内涵,对起重机械电气设计、安装施工、产品检验等工作,具有一定的指导价值。

Crane is a kind of special equipment,and its safety has been paid great attention.Relevant standards have been formulated for the safety of crane design,installation and use.In terms of crane grounding method and grounding fault protection,the standard lacks detailed provisions.The enterprises’understanding and mastery of the standards are inconsistent,and the design and construction are not standardized,resulting in potential safety hazards such as personal electric shock and burning of crane electrical equipment.Referring to relevant standards and theories,by analyzing and comparing the working principles of different power grids and grounding short-circuit calculation,it was proposed that the grounding and grounding fault protection of crane was a systematic project.It was concluded that the grounding method of feed system,guide rail,track beam,steel structure and electrical equipment on crane,as well as the type of grounding fault protection switch only depended on the type of power grid,and the standard practice and implementation rules of each link grounding were provided.The achievement effectively solves the hidden danger of single-phase grounding fault,enriches and supplements the connotation of the standard,and has certain guiding value for crane electrical design,installation and construction,product inspection and so on.