Metal fault analysis and preventive measures for grounding accessories of 110kV cable outdoor terminal

Abstract

Abstract There were three grounding metal faults of the 110 kV outdoor cable terminals, i.e., cracked weld between grounding copper block and the cable tail pipe, no fastened grounding copper block connecting bolt and no fixed grounding wire connected to the grounding copper block, respectively. Precautionary measures were proposed from three stages of design, including installation, operation and maintenance. It was recommended to improve the welding design during the design phase. In the installation stage, it was necessary to strictly control the construction quality control, attach importance to the connection of bolts and gaskets, and improve the fixing of the grounding wire. For the operation and maintenance phase, it was important to strengthen the targeted inspection of the grounding point of the cable terminal and the grounding wire, and to non-destructively test the quality of the weld during the power failure maintenance, which was an effective measure to ensure the safe operation of the grounded metal.