井下局部扇风机的控制设备多采用熔断器作断相保护,加之井下潮湿、粉尘的环境,又无专职值班人员监护的情况下,经常发生电机单相运转烧毁,偶尔也出现堵转烧毁的现象。这样既影响安全生产,又不经济。这里介绍几种风机简易保护器。 一、断相、堵转的检出 断相、堵转鉴别器如图1所示,是由三个磁环线圈LH_A、LH_B和LH_C组成,磁环线圈原边串在主回路中,副边首尾相联接成开口三角形。在电机带负荷运转时,使铁淦氧磁环工作在饱和状态下,这时它副边的电压波形是以基波和三次谐波为主的尖峰波,如图2所示。在三相对称运行时, Local fan fan control equipment and more use of fuses for the phase protection, coupled with the underground wet, dusty environment, and no full-time staff custody case, the motor often occurs single-phase operation burned, and occasionally blockage burn phenomenon . This will not only affect the safety of production, but also not economical. Here are several fan simple protector. First, the phase loss, stalling the detection of phase, blockage Discriminator shown in Figure 1, is composed of three magnetic coil LH_A, LH_B and LH_C composed of the primary coil of the magnetic loop in the main loop, the secondary Head and tail connected to form an open triangle. In the motor with load operation, the ferrite ring work in saturation, then it is the secondary side of the voltage waveform is based on the fundamental and third harmonic spikes, as shown in Figure 2. In the three-phase symmetrical operation,