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.主電源恢復時,不能自動轉(zhuǎn)換到主電源 C.主電源應有過流保護措施 D.主、備電源的轉(zhuǎn)換不應使控制器產(chǎn)生誤動作
A.120Hz B.90Hz C.60Hz D.50Hz