For the operation distribution box exposed to the hot sun in midsummer, sometimes the temperature in the box exceeds 60 ℃ due to the direct sunlight, the reflection of heat from the cement ground and the heat generated by the equipment in the box. The contact resistance of electrical contacts increases due to too high temperature, and the increase of contact resistance intensifies heating. Such a vicious cycle will lead to contact burnout. At the same time, too high temperature will also affect the stability of protection performance, action reliability and measurement accuracy of distribution box.
With the implementation of urban and rural power grid construction and transformation project, the wide use of distribution box, the continuous increase of social power consumption, some problems in operation have been exposed, which should be paid attention to. Such a high temperature can easily cause the insulation aging of electrical coils and leads to breakdown and burn out. Distribution boxes with shutters on both sides and incomplete separation in the middle shall be selected as far as possible to form air convection and heat dissipation. In addition to ensuring ventilation, the box shall avoid direct sunlight at noon as far as possible, and the ground shall be non gravel.
