电能表正转(比正常情况下慢很多)或几乎不转。原因:正常情况下三相三线电能表第一元件所用所用电流为Ia电压为Uab功率表达式为Uab·Ia·cos(30°+Φ)三相三线电能表第二元件所用所用电流为Ic电压为Ucb功率表达式为Ucb·Ic·cos(30°+Φ)总功率=Uab·Ia·cos(30°+Φ)+Ucb·Ic·cos(30°+Φ)c相电流接反后总功率=Uab·Ia·cos(30°+Φ)+Ucb·(-Ic)·cos(30°+Φ)Φ为功率因数角。负载平衡,