The existing defect of overload, openphaseprotection of minitype flameproof motor used in coal mine was analysed and its improved protection scheme was presented.
分析了煤矿井下小型隔爆电动机过载、断相保护存在的缺陷,提出了改进的保护方案。
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If no openphaseprotection is available during the operation course of three-phase equipment, it shall operate abnormally under open phase condition or shall be burnt if the case is serious.
Based on the analysis of main fault types of LV (Low Voltage) flameproof motor, the negative sequence protection principle is proposed for its asymmetric short circuit fault and openphase fault.