A.50s B.60s C.30s D.40s
A.120s B.150s C.60s D.90s
A.主電源斷電時,能自動轉(zhuǎn)換到備用電源 B.主電源恢復(fù)時,不能自動轉(zhuǎn)換到主電源 C.主電源應(yīng)有過流保護措施 D.主、備電源的轉(zhuǎn)換不應(yīng)使控制器產(chǎn)生誤動作