氧化锌避雷器直流1mA电压与初始值或制造厂规定值比较,变化不应大于±5%()
Signs of racking stresses generally appear at the ().
A. Bow and stern shell frames and plating
B. Junction of the frames with the beams and floors
C. Garboard strake,at each side of the keel
D. Thrust bearing of the main shaft
在中性点直接接地系统中,可以采用以电容式电压互感器替代电磁式电压互感器来消除电压互感器的串联谐振。()
同类比较判断法根据同组三相设备、同相设备之间及同类设备之间对应部位的温差进行比较分析。()