A.通道設(shè)備故障 B.保護(hù)裝置故障 C.斷路器輔助接點故障 D.遙信電源故障
A.應(yīng)當(dāng) B.必須 C.不應(yīng) D.可以
A.1ms B.2ms C.5ms D.10ms