... when lay. Otherwise it should be preheated.7. Working Frequency Voltage Test: 2.5Uo+2kV/5min without puncture.Note: The single ... should be used.(cable, power cable, power wire, electric cable, electrical cable, pvc insulated cable, pvc insulated power cable, pvc cable, pvc power cable, pvc sheathed cable, pvc sheathed power cable, insulated cable) 0.6/1kV ...