Failure Reason of Tension Clamp for High Voltage Electricity Transmission

The corrosion failure reason of a tension clamp was investigated by the analysis of the macro-morphology, chemical composition and corrosion products of the tension clamp for high voltage electricity transmission and the holding conductor. The results show that some aluminium strands broke during the pressure connecting process of the clamp, which made acidic rainwater easily run into the inside of the pressure connecting pipe during service. So that the joint surface between clamp and aluminium conductor steel reinforced wires corroded and produced corrosion products, resulting in the increased resistance of the tension clamp. With the corrosion continuing, the resistance of the clamp increased, followed by the increase of the temperature. When the clamp temperature increased over the critical temperature, the thermal equilibrium state was broken, finally the clamp was overheated, resulting in the high-temperature combustion failure. The on-line infrared monitoring of temperatures of the clamp pressure connecting pipe should be strengthened, and the pressure connecting pipe with abnormal temperatures should be replaced in time.