Underground Power Cable Failure

A substantial percentage occurs at splices terminations and joints.

Underground power cable failure.

Final results of a failure a cable failure almost always exhibits itself as either an open circuit or a short circuit. Excessive heating of the cable will cause degradation of the insulation and sheathing material and premature failure. Causes of faults in underground cables most of the faults occur when moisture enters the insulation. 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.

Dividing the cable into successively smaller sections will enable you to narrow down the search for a fault. Open circuits are more common in low voltage cables than at medium or high voltage. 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. 1 risks reducing cable reliability because it depends on physically cutting and splicing the cable.

Other causes include mechanical injury during transportation laying process or due to various stresses encountered by the cable during its working life. Major causes are due to water ingress and poor workmanship. The lead sheath is. Open circuits are usually the result of failed connectors or broken and or corroded conductors.

The paper insulation provided inside the cable is hygroscopic in nature. Heat shrink covers can be used to waterproof these junctions and improve reliability. However the detection and localization of cable fault is challenging due to the limited access to the cable burned under the ground.