A.轉(zhuǎn)子回路接觸不良 B.轉(zhuǎn)子繞組兩處接地而發(fā)生短路 C.繞組與滑環(huán)接點(diǎn)接觸不良 D.電壓過(guò)低
A.5 B.10 C.20 D.30
A.1% B.5% C.10% D.20%