When the electrical equipment designed and manufactured according to Chinese standards, the upper limit of ambient temperature should not exceed 40 ℃, while the operating low-voltage distribution box exposed to the scorching sun in midsummer, due to the direct sunlight, the reflection of heat on the cement floor and the heat generated by the equipment in the box, sometimes the temperature in the box exceeds 60 ℃. Such a high temperature is very easy to cause the insulation aging of electrical coil and lead wire, which will lead to breakdown and burn out; the contact resistance of electrical contact will increase due to high temperature, and the increase of contact resistance will aggravate the heating, which will eventually lead to the contact burning out; at the same time, too high temperature will also affect the stability of electrical protection performance, the reliability of action and the accuracy of measurement. Therefore, it is suggested that:

1. Low voltage distribution box with louvers on both sides and incomplete separation in the middle should be selected as far as possible to form air convection and heat dissipation;

2. The box body should be made of natural stainless steel, which is not easy to rust and has heat reflection effect. If the coating with heat insulation performance can be sprayed regularly to reduce the thermal radiation, the effect is more ideal;

3. In addition to ensuring ventilation, the box body should avoid direct sunlight in the afternoon as far as possible, and the ground should be non gravel;

4. Avoid overload operation of the equipment in high temperature season, and reduce the heat released by the equipment in the box as much as possible.