电机断相保护器在工矿企业应用较广。1975年我院研究成的华-11型简易断相保护器(图1)具有线路简单、节能、保护器本身元件故障有自检能力和通用性强等优点。但考虑到电机空载断相及供电网路的波动因素,该型只能适应10千瓦以上功率电机穿心。 Motor phase failure protector is widely used in industrial and mining enterprises. In 1975, our hospital researched Hua-11 type simple phase failure protector (Figure 1), which has the advantages of simple circuit, energy saving, fault protection of the protector itself, self-checking capability and versatility. However, taking into account the motor no-load phase failure and power supply network fluctuations, the type can only adapt to more than 10 kW power motor through the heart.