System category A——This category comprises those systems in which any phase conductor that comes in contact with earth or an earth conductor. is disconnected from the system within 1 min.
System category B ——This category comprises those system which,under faultconditions,are operated,are operated for ashorttimewith one phase earthed.This period should not exceed 1 h..Fora longer period, not exceeding 8h on any occasion, can be tolerated.The total duration of earth faults in any year should not exceed 125h.
System categeory C——This category comprises all systems which do not fall into A and B
電纜的型號(hào)Type of cable
型號(hào) Type 名稱 Designation 適用范圍 Application
YJV 銅芯交聯(lián)聚乙烯絕緣氯乙烯護(hù)套電力電纜 Copper conductor,XLPE insulated and PVC sheathed power cable 室內(nèi)、隧道及電纜溝等場(chǎng)所,不能承受機(jī)械外力。單芯電纜不允許敷設(shè)在磁性管道中。 For laying indoors 、 intunnel or cable trench,unable to bear external mechan-icalforces.Single-core cable in magnetic duct is not permissible
YJLY 鋁芯交聯(lián)聚乙烯絕緣乙烯護(hù)套電力電纜 Aluminium conductor, XLPE insulated and PVC sheathed power cable
YJY 銅芯交聯(lián)聚乙烯絕緣氯乙烯護(hù)套電力電纜 Copper conductor ,XLPE insulated and PEsheathed power cable