Experimental study on the influencing factors and regularities of external contact heating in isolating switches

Abstract To address the overheating phenomenon of the contact surfaces in outdoor isolating switches, the contact components were disassembled, and a multi-factor experimental platform was established to study the correlation between various factors and heating in electrical equipment. Experimental analysis revealed that when the contact resistance exceeds 120 μΩ and the contact current exceeds 500 A, the contact area tends to heat up or even overheat. The effect of wind speed on heat dissipation at the contact point becomes more gradual with increasing wind speed, while the variation in ambient temperature corresponds to the same change in contact temperature rise under identical conditions.