For people who have been engaged in electrical work for a long time, it is easy to recognize such a law: sudden accidents of Small Power Distribution Unit (SPDU) often occur in the dead of night, while mechanical and electrical equipment faults mostly occur in spring and summer of seasonal supermarkets and in the season of sudden change of temperature (sudden decrease or increase), electrical equipment faults are also easy to occur.

Humidity and mold: moist air is conducive to the growth of mold. Practice shows that when the temperature is 25-30 degrees and the relative humidity is 75% ~ 95%, it is a good condition for mold growth. Therefore, if the ventilation is not good, the growth rate of mold will be accelerated. Mold contains a lot of moisture, which will greatly reduce the insulation performance of the equipment. For some porous insulating materials, the mold root can also go deep into the interior of the material, resulting in insulation breakdown.

In the Small Power Distribution Unit (SPDU), the acidic substances secreted during the metabolism of mold interact with the insulation, which reduces the insulation performance of the equipment. Humidity and metal corrosion: humid air will rust the conductive metal, magnetic conductive silicon steel sheet and metal shell in power equipment. It will reduce the performance and service life of the equipment, and even cause electrical failure.

Effect of excessive temperature: the equipment has a certain temperature due to internal loss. If the ambient temperature is too high or the air fluidity is poor, so that the heat of the equipment cannot be dispersed in time, the equipment will trip due to overheating and even burn the equipment.

The electronic products in the Small Power Distribution Unit (SPDU), such as residual current action protector and electronic meter, will seriously affect the service life of the product when operating at high temperature, as well as the stability of protector performance, the reliability of action and the accuracy of measurement. Reactive power compensation capacitors and fuses operating at high temperature will also shorten their service life.