Corrosion Effect in Underground LV Distribution Networks in Domestic and Commercial Buildings

Abstract

The underground distribution network is an essential part of our domestic and commercial area buildings. PVC cables are mostly used for household wiring, including underground cables installation in LV distribution networks. Small cracks in cable insulation or gaps in connectors during or after installation can cause water to seep through onto the conductor. Heated conductors in the presence of water causes corrosion of the conductor and eventual failure. These are the most common causes of emerging faults in underground networks. Such faults occur frequently and result into a permanent failure soon after the occurrence. Failures mostly arise in low voltage levels in distribution systems and have a large impact on their durability. In addition to the fact that the majority of customers are affected, the impact to annual customer minutes lost is significant and the annual expenses of resolving the outages can become large. Al/PVC/PVC cables are mostly used for commercial installation, including four different sizes: 10 mm2 (2-core, 4-core), 120 mm2 (4-core) and 240 mm2 (4-core). In this research, the effect of corrosion on these sizes was studied under electric stress. Deterioration of an Aluminum conductor was used to investigate the effects of heat and voltage. Such parameters highly influence the rate of corrosion.