运行中电动机过热,原因可能是水泵装配不良,动、静部分发生摩擦卡住。
参考答案:对
改错。
( ) 1. Doesn't today a holiday? ________________
A B C
( ) 2. Here are a diary. ________________
( ) 3. Coming back tomorrow. ________________
( ) 4. What is she do on Thursday after school? ________________
( ) 5. He watches TV at the home on Monday. ________________
( ) 6. Do you go to school everyday? ________________
某沿海电厂二期扩建4台600MW燃煤机组,电厂附近已建有400t的大件码头。电厂一期以220kV升高电压接入系统,二期4×600MW机组均接入厂内500kV配电装置,500kV出线规模为2回,厂内两级电压间交换容量为360MVA。
自耦变压器的第三绕组容量宜为( )。
A.90MVA; B.60MVA; C.210MVA; D.50MVA。