Failure caused by improper selection of electrical appliances in Street Light Pole Top Box

When the Street Light Pole Top Box operates outdoors, it will not only generate high temperature under the direct irradiation of the sun, but also generate heat during operation. Therefore, in the high-temperature season in midsummer, the temperature in the box will reach more than 60 ℃. At this time, the temperature greatly exceeds the environmental temperature specified by these electrical appliances, so the fault caused by overheating of electrical components in the distribution box will occur.

When the Street Light Pole Top Box was manufactured, the capacity of AC contactor was not properly selected. AC contactors with the same capacity were installed for different outgoing circuits, and the imbalance of three-phase load was not considered. However, the current level of some outgoing contactors was not selected by one current level based on the normal selection model, resulting in the burning out of AC contactor during operation in high temperature season in summer.