電纜故障顯示器

　　電(dian)纜故障指示(shi)器(qi)由顯(xian)示(shi)器(qi)和傳感(gan)器(qi)兩部分(fen)組(zu)成，傳感(gan)器(qi)負責探測電(dian)纜通過的電(dian)流(liu)，顯(xian)示(shi)器(qi)負責對傳感(gan)器(qi)傳送來的電(dian)流(liu)信息進(jin)行判斷及做出故障指示(shi)動作。下圖是電纜故障測試儀的各種類型的電(dian)纜故障(zhang)顯示器：

　　

　　正常情況下，故(gu)障(zhang)(zhang)指示(shi)(shi)(shi)器(qi)不(bu)動(dong)作(zuo)，故(gu)障(zhang)(zhang)指示(shi)(shi)(shi)燈不(bu)亮。當(dang)通過電(dian)(dian)(dian)(dian)(dian)(dian)纜的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)達到故(gu)障(zhang)(zhang)指示(shi)(shi)(shi)器(qi)設定的(de)(de)故(gu)障(zhang)(zhang)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)值(zhi)時，顯示(shi)(shi)(shi)器(qi)會對(dui)由傳感器(qi)傳來的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)進行判(pan)斷，如(ru)果過電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)持(chi)續不(bu)到100～200 ms，則此電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)可能是電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)起(qi)動(dong)等因(yin)素引起(qi)的(de)(de)瞬間起(qi)動(dong)過電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，不(bu)是故(gu)障(zhang)(zhang)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，因(yin)此顯示(shi)(shi)(shi)器(qi)不(bu)動(dong)作(zuo)。如(ru)果過電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)持(chi)續超(chao)過100～200 ms，則判(pan)斷為(wei)故(gu)障(zhang)(zhang)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，顯示(shi)(shi)(shi)器(qi)動(dong)作(zuo)，指示(shi)(shi)(shi)燈閃爍(shuo)顯示(shi)(shi)(shi)。

　　顯(xian)示器動作(zuo)后再作(zuo)一次判斷，如果2 s內電纜(lan)電流已恢(hui)復正常，說(shuo)明(ming)上級開關重合(he)閘(zha)成功，故障點已被排(pai)除，恢(hui)復正常供電狀態(tai)，顯(xian)示器回復初始(shi)狀態(tai)，指(zhi)示燈熄(xi)滅。如果2 s內電纜(lan)電流消失(shi)，說(shuo)明(ming)故障已引發上級開關跳閘(zha)而導致(zhi)電纜(lan)失(shi)壓，則確定為故障，顯(xian)示器保持動作(zuo)，指(zhi)示燈繼續閃爍，直到達到預(yu)設(she)的時間(jian)限值或受到人(ren)工手動復位(wei)為止。