Underground Power Cable Failure

Open circuits are more common in low voltage cables than at medium or high voltage.

Underground power cable failure.

The heat may come from an external source or may be generated by the resistance to current flow in the conductor a particular problem if the cable is overloaded and or underrated for the application. Causes of faults in underground cables most of the faults occur when moisture enters the insulation. There are two basic methods of locating an underground cable fault. Excessive heating of the cable will cause degradation of the insulation and sheathing material and premature failure.

The paper insulation provided inside the cable is hygroscopic in nature. Final results of a failure a cable failure almost always exhibits itself as either an open circuit or a short circuit. Sectionalizing this procedure as shown in fig. 1 risks reducing cable reliability because it depends on physically cutting and splicing the cable.

Open circuits are usually the result of failed connectors or broken and or corroded conductors. However the detection and localization of cable fault is challenging due to the limited access to the cable burned under the ground. Other causes include mechanical injury during transportation laying process or due to various stresses encountered by the cable during its working life. The use of underground cables is essential in power distribution networks as they mitigate the issues related to space availability and minimise line breakdown and increase system reliability.

Major causes are due to water ingress and poor workmanship. Dividing the cable into successively smaller sections will enable you to narrow down the search for a fault. The lead sheath is.