电机保护器的作用是给电机全面的保护，在电机出现过载、缺相、堵转、短路、过压、欠压、漏电、三相不平衡、过热、轴承磨损、定转子偏心时，予以报警或保护的装置。
The function of the motor protector is to protect the motor completely, and alarm or protect the motor when the motor is overloaded, missing phase, plugging, short circuit, overvoltage, undervoltage, leakage, three-phase unbalance, overheating, bearing wear and eccentric rotor.
电机保护常识
Common sense of motor protection
1．为什么现在的电机比过去 更容易烧毁？ 由于绝缘技术的不断发展，在电机的设计上既要求增加出力，又要求减小体积，使新型电机的热容量越来越小，过负荷能力越来越弱；再由于生产自动化程度的提高，要求电机经常运行在频繁的起动、制动、正反转以及变负荷等多种方式，对电机保护装置提出了更高的要求。另外，电机的应用面更广，常工作于环境极为恶劣的场合，如潮湿、高温、多尘、腐蚀等场合。所有这些，造成了现在的电机比过去更容易损坏，尤其是过载、短路、缺相、扫膛等故障出现频率高。
1. why is the current motor more easily burned than before- Because of the continuous development of insulation technology, the design of the motor requires both increasing output and reducing the volume, so that the heat capacity of the new type of motor is becoming smaller and less, and the capacity of the overload is becoming weaker and weaker. And the increase of the degree of automation of production requires that the motor often run in frequent starting, braking, positive inversion and load change. In many ways, higher requirements for motor protection devices are put forward. In addition, the application of motor is wider, often working in extremely harsh environment, such as humidity, high temperature, dust and corrosion. All of these caused the current motor to be more easily damaged than before, especially the overload, short circuit, lack of phase and sweeping bore had the highest frequency.
2．为什么传统的保护装置保护效果不甚理想？ 传统的电机保护装置以热继电器为主，但热继电器灵敏度低、误差大、稳定性差，保护不可靠。事实也是这样，尽管许多设备安装了热继电器，但电机损坏而影响正常生产的现象仍普遍存在。
2. why is the traditional protection device less effective- The traditional motor protection device is mainly based on thermal relay, but the thermal relay has low sensitivity, large error and poor stability, and the protection is not reliable. The same is true. Although many devices are equipped with thermal relays, the phenomenon of motor damage and normal production is still widespread.
3、电机保护的发展现状？ 目前电机保护器已由过去的机械式发展为电子式和智能型，可直接显示电机的电流、电压、温度等参数，灵敏度高，可靠性高，功能多，调试方便，保护动作后故障种类一目了然，既减少了电机的损坏，又极大方便了故障的判断，有利于生产现场的故障处理和缩短恢复生产时间。另外，利用电机气隙磁场进行电机偏心检测技术，使电机磨损状态在线监测成为可能，通过曲线显示电机偏心程度的变化趋势，可早期发现轴承磨损和走内圆、走外圆等故障，做到早发现，早处理，避免扫膛事故发生。
3. Current status of motor protection- At present, the motor protector has been developed from the past mechanical type to electronic and intelligent type. It can directly display the electric current, voltage, temperature and other parameters of the motor. It has high sensitivity, high reliability, many functions and convenient debugging. The type of fault is clear after the protection action, which not only reduces the damage of the motor, but also greatly facilitates the judgment of the fault. Breaking is conducive to fault handling and shortening the production time at the production site. In addition, using the motor air gap magnetic field to carry out the motor eccentricity detection technology, make it possible to monitor the motor wear on line. Through the curve display of the change trend of the motor eccentricity, the bearing wear and the internal circle and the outer circle can be found early, so as to find early, early and avoid the accident of sweeping the bore.
4．保护器选择的原则？ 合理选用电机保护装置，实现既能充分发挥电机的过载能力，又能免于损坏，从而提高电力拖动系统的可靠性和生产的连续性。具体的功能选择应综合考虑电机的本身的价值、负载类型、使用环境、电机主体设备的重要程度、电机退出运行是否对生产系统造成严重影响等因素，力争做到经济合理。
The principle of 4. protector selection- The rational use of the motor protection device can not only give full play to the overload capacity of the motor, but also avoid the damage, thus improving the reliability and production continuity of the electric drive system. The specific function selection should take into account the value of the motor itself, the type of the load, the use environment, the importance of the main equipment of the motor, the serious influence of the motor exit operation on the production system and so on, and strive to achieve the reasonable economy.
5、理想的电机保护器？ 理想的电机保护器不是功能多，也不是所谓先进的，而是应该满足现场实际需求，做到经济性和可靠性的统一，具有较高的性能价格比。根据现场的实际情况合理地选择保护器的种类、功能，同时考虑保护器安装、调整、使用简单方便，更重要的是要选择高质量的保护器。
5. Ideal motor protector- The ideal motor protector is not the most functional, nor the most advanced, but should meet the actual needs of the field, achieve the unification of economy and reliability, and have a high performance and price ratio. According to the actual situation, the type and function of the protector are selected rationally, and the installation, adjustment and use of the protector are simple and convenient, and the more important thing is to choose the high quality protector.