本书以常用变压器、电动机、低压电气设备或电器元件的认知、检测、故障分析及处理为主线，以检修技术为基准进行编写。 全书共设计7个项目，内容包括：电气安全基本知识，变压器的使用与维护，电动机的使用与维护，接触器、继电器、低压开关电器、熔断器、主令电器等低压电器的使用与维护，电气控制线路的运行与维护、电力电容器的运行与维护、供配电线路的运行与维护。 本书全面覆盖初、中级电工操作证考试大纲的要求，尽可能多地介绍实际操作方面的技能，并附有实际操作范例，具有很强的针对性和实用性，既能满足职业院校相关专业的教学需要，又能适应工厂对低压电工操作培训的迫切需要。经过本教材学习，大部分学员都能达到初、中级电工操作证考试大纲要求的水平。本书可用作大中专院校电工作业相关专业的教学用书，也可用作初、中级电工操作证考试的培训用书。

徐作华：女，长春职业技术学院电气工程教授，长期从事一线教学工作及校企合作，主编过3部教材，以副主编身份参与编写3部教材，发表过10多篇论文，其中包括2篇核心期刊论文。

目录 项目 1 电气安全基本知识 ············································································ （1） 任务 1.1 触电急救 ··················································································· （1） 1.1.1 触电与防触电措施 ········································································· （1） 1.1.2 防止触电的技术措施 ······································································ （7） 1.1.3 触电急救 ····················································································· （9） 1.1.4 安全用电意义 ·············································································· （14） 1.1.5 安全用电标志 ·············································································· （14） 1.1.6 生活中安全用电的注意事项 ··························································· （15） 任务 1.2 电气火灾的扑救 ········································································· （16） 1.2.1 电气火灾的原因 ··········································································· （16） 1.2.2 电气火灾扑救方法 ········································································ （17） 任务 1.3 防雷和接地装置的运行与维护 ······················································· （19） 1.3.1 雷电现象及危害 ··········································································· （20） 1.3.2 防雷装置 ···················································································· （22） 1.3.3 防雷保护 ···················································································· （27） 1.3.4 接地装置的运行与维护·································································· （30） 1.3.5 低压配电系统的等电位连接 ··························································· （34） 思考与练习 1 ··························································································· （35） 项目 2 变压器的使用与维护 ········································································ （37） 任务 2.1 变压器认知 ··············································································· （37） 2.1.1 变压器的结构 ·············································································· （37） 2.1.2 变压器的分类 ·············································································· （41） 2.1.3 变压器的工作原理 ········································································ （41） 2.1.4 变压器的铭牌数据 ········································································ （45） 2.1.5 单相变压器的绕组极性及判定 ························································ （47） 2.1.6 变压器空载试验和短路试验 ··························································· （48） 2.1.7 变压器的运行特性 ········································································ （50） 2.1.8 变压器的损耗、效率及效率特性 ····················································· （51） 任务 2.2 常用变压器的使用与维护 ····························································· （52） 2.2.1 互感器 ······················································································· （52） 2.2.2 自耦变压器 ················································································· （55） 2.2.3 三相变压器 ················································································· （56） 2.2.4 变压器的维护及故障分析处理 ························································ （59） 思考与练习 2 ·························································································· （62） 项目 3 电动机的使用与维护 ········································································ （65） 任务 3.1 三相异步电动机的运行与维护 ······················································· （65） 3.1.1 电动机简介 ················································································ （65） 3.1.2 三相异步电动机的结构 ································································· （66） 3.1.3 三相异步电动机铭牌上的数据 ························································ （69） 3.1.4 三相异步电动机的工作原理 ··························································· （71） 3.1.5 三相异步电动机的运行原理 ··························································· （75） 3.1.6 三相异步电动机的运行特性 ··························································· （76） 3.1.7 三相异步电动机的工作特性 ··························································· （80） 3.1.8 三相异步电动机的起动 ································································· （80） 3.1.9 三相异步电动机的调速 ································································· （85） 3.1.10 三相异步电动机的制动 ······························································· （87） 任务 3.2 直流电机的使用与维护 ································································ （94） 3.2.1 直流电机的基本工作原理 ······························································ （94） 3.2.2 直流电机基本结构 ······································································· （96） 3.2.3 直流电机的额定值及铭牌 ······························································ （99） 3.2.4 直流电机的励磁方式与工作原理 ···················································· （100） 3.2.5 直流电机的工作特性 ··································································· （101） 3.2.6 直流电机的起动、调速与制动 ······················································· （104） 思考与练习 3 ························································································· （109） 项目 4 低压电器的使用与维护 ···································································· （112） 任务 4.1 电器的基本知识 ········································································ （112） 4.1.1 电器的分类 ··············································································· （112） 4.1.2 低压电器的作用 ········································································· （113） 任务 4.2 接触器的使用与维护 ·································································· （115） 4.2.1 接触器的分类及结构 ··································································· （115） 4.2.2 接触器的符号、型号及选用方法 ···················································· （118） 4.2.3 接触器的使用和维修 ··································································· （120） 任务 4.3 继电器的使用与维护 ·································································· （122） 4.3.1 继电器 ····················································································· （122） 4.3.2 常用电磁式继电器 ······································································ （124） 任务 4.4 低压开关电器的使用与维护 ························································· （132） 4.4.1 低压刀开关 ··············································································· （133） 4.4.2 低压断路器（自动空气开关） ······················································· （134） 4.4.3 转换开关 ·················································································· （136） 任务 4.5 熔断器的使用与维护 ·································································· （137） 4.5.1 熔断器基础 ··············································································· （138） 4.5.2 熔断器的种类及用途 ··································································· （138） 4.5.3 熔断器的安秒特性 ······································································ （139） 4.5.4 熔断器的选用 ············································································ （140） 任务 4.6 主令电器的使用与维护 ······························································ （140） 4.6.1 控制按钮 ·················································································· （141） 4.6.2 行程开关 ·················································································· （142） 思考与练习 4 ························································································· （145） 项目 5 电气控制线路的运行与维护 ····························································· （146） 任务 5.1 电动机基本控制线路的绘制 ························································ （146） 5.1.1 常用的电气元件的图形符号和文字符号 ·········································· （146） 5.1.2 电气控制系统图的绘制原则 ························································· （149） 任务 5.2 三相异步电动机直接起动控制线路的运行与维护 ····························· （152） 5.2.1 点动控制线路的运行与维护 ························································· （152） 5.2.2 自锁控制线路的运行与维护 ························································· （154） 5.2.3 多地控制线路的运行与维护 ························································· （156） 5.2.4 正反转控制线路的运行与维护 ······················································ （156） 5.2.5 三相异步电动机顺序控制线路的运行与维护 ···································· （159） 任务 5.3 三相异步电动机降压起动控制线路的运行与维护 ····························· （161） 5.3.1 串电阻降压起动控制线路的运行与维护 ·········································· （162） 5.3.2 星−角降压起动控制线路的运行与维护 ············································ （162） 5.3.3 自耦变压器降压起动控制线路的运行与维护 ···································· （163） 思考与练习 5 ························································································· （164） 项目 6 电力电容器的运行与维护 ································································ （169） 任务 6.1 电容器认知 ············································································· （169） 6.1.1 并联电容器的结构和型号 ···························································· （169） 6.1.2 并联电容器的作用和种类 ···························································· （170） 6.1.3 无功补偿的基本原理 ··································································· （170） 6.1.4 电容器的选择 ············································································ （171） 任务 6.2 电容器的运行与维护 ································································· （172） 6.2.1 电容器的安装 ············································································ （172） 6.2.2 电容器的接线 ············································································ （173） 6.2.3 电容器的安全运行 ······································································ （173） 6.2.4 电容器的保护 ············································································ （174） 6.2.5 电容器的投入和退出 ··································································· （174） 6.2.6 电容器的操作 ············································································ （174） 6.2.7 电容器运行中的故障处理 ···························································· （175） 思考与练习 6 ························································································· （175） 项目 7 供配电线路的运行与维护 ································································ （176） 任务 7.1 导线、电缆的选择 ···································································· （176） 7.1.1 导线和电缆型号的选择 ································································ （176） 7.1.2 电缆、母线及导线的截面选择与校验 ·············································· （181） 任务 7.2 供配电线路接线方式选择 ···························································· （188） 7.2.1 高压配电线路的接线方式 ····························································· （188） 7.2.2 低压配电线路的接线方式 ····························································· （192） 7.2.3 高、低压配电线路的电网设计与接线方式选择 ·································· （194） 任务 7.3 架空线路的敷设、运行与维护 ······················································ （195） 7.3.1 架空线路的结构 ········································································· （196） 7.3.2 架空绝缘线路的敷设 ··································································· （204） 7.3.3 架空配电线路运行与维护 ····························································· （210） 任务 7.4 电缆线路的敷设、运行与维护 ······················································ （216） 7.4.1 工厂的电缆线路 ········································································· （217） 7.4.2 电缆的敷设 ··············································································· （219） 7.4.3 电缆线路常见故障及处理 ····························································· （229） 任务 7.5 车间线路的敷设、运行与维护 ······················································ （230） 7.5.1 车间线路导线的选择 ··································································· （230） 7.5.2 车间动力电气平面布线图 ····························································· （230） 7.5.3 车间电力线路的敷设 ··································································· （233） 思考与练习 7 ························································································· （234） 附录 A 电工作业常用数据表 ······································································ （235） 参考文献 ································································································· （239）