Conductive Water Film Discharge Phenomenon At Cable Terminals In Rainy And Foggy Environments

The conductivity mechanism of the water film is closely related to the degree of contamination on the copper lugs surface. In rainy or foggy weather, salt, dust, and other contaminants adhere to the Aluminum Cable Lug surface, dissolving in the water to form an electrolyte film. When voltage is applied to this conductive film at the Compression Cable Lug terminals, leakage current is generated. The current flow generates heat, causing localized evaporation of the water film and forming a dry zone. Voltage concentration in this dry zone area triggers a localized electric arc.

The harmfulness of this creepage discharge to the cable lugs surface cannot be ignored. In the initial stage, the discharge exhibits a glowing or flashing state, accompanied by a slight sound and halo. As the discharge channel extends along the surface of the wire lugs, it may eventually connect the two poles, causing a short circuit fault. Long-term and repeated creepage discharge can also corrode the insulation material of electrical lugs, accelerate its aging process, and seriously affect the stability of the electrical system operation.