Failure Analysis on Bursting Disc of 5052 Current Transformer Used in 550kV Substation

In order to ensure the substation operating safely and stably in a long time, this paper analyses spot inspection, main chemical element content, fracture morphology, metallographic structure, microhardness, adhesive materials and blasting verification test, to obtain the failure cause of bursting disc of 5052 current transformer used in 550kV Substation. The results shows: the fault cause of 5052 current transformer is the bruising of bursting disc arch face of 5052 current transformer during the carrying or assembling process. The bruising markedly reduces the bursting pressure and use stability of bursting disc to cause bursting disc arch face instability, inversion, blasting under normal conditions for 3 years. The cracking along weakening groove leads to the leakage of SF
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which decrease the insulativity. Thus, the current transformer appears a discharge ablation fault.