Friday, September 16, 2022
问题:当证明变压器的自动跳闸不是由于其内部故障引起的,而是由于()引起...
Friday, September 16, 2022
问题:当电流互感器一次电流是从端L1流入,L2流出时,其二次侧的()端...
Sunday, September 11, 2022
问题:西门子MM440变频器可外接开关量,输入端⑤—⑧段作为多段速给定端,可预置()不同的给定频率值。A、15个B、16个C、4个D、8个...
Saturday, April 29, 2023
Friday, September 16, 2022
Sunday, September 11, 2022
问题:根据三极管内PN结的单向导电性,如果正反向电阻都为(),说明其内...
Friday, September 16, 2022
Friday, September 16, 2022
问题:在FX<sub>2N</sub>系列PLC中,T200的定时精度...
Friday, September 16, 2022
Friday, September 16, 2022
问题:一台380V交流电动机停电测量绝缘电阻,绝缘电阻的合格范围()...
Tuesday, September 13, 2022
问题:操作票填写时,被操作的开关要填写双重名称,即设备的名称和编号。...
Sunday, September 11, 2022
Sunday, September 11, 2022
Friday, September 16, 2022
问题:在同一保护接零系统中,如某设备接零确有困难而采用接地保护,则应采...
Sunday, September 11, 2022
问题:导线端部接到接线柱上,如单股导线截面在()以上,应使用不同规格的...
Sunday, September 11, 2022
问题:保护接地与防雷接地共用接地装置时,接地电阻不应大于1欧。...
Sunday, September 11, 2022
Friday, September 16, 2022
Sunday, September 11, 2022
Friday, September 16, 2022