This mainly refers to the influence of external factors such as temperature, humidity, rain, dust, and small animals. There are three types of reactive power compensation devices installed, namely, the compensation cabinet in the power distribution room, the compensation device for the box type, and the on-column compensation box for the common distribution of the line. The former two can be regarded as the indoor installation form, and the on-column compensation box of the common distribution is an outdoor installation form, and the working environment is the worst.

    The device cabinet installed outdoors is in direct contact with the outside air environment, the heat insulation effect is poor, the temperature inside the box changes drastically, and the condensation phenomenon is easy to occur, which is susceptible to external temperature, humidity, rain, dust, and small animals. These factors are affected. To the reliability and longevity of the device.

    a. Temperature. In recent years, the technical parameters of the products provided by the factory have different expressions of ambient temperature, such as 40 ° C, 55 ° C, 60 ° C, 65 ° C and so on. The author has done temperature test in the hottest summer: when the temperature is 37 °C in sunny days, the temperature of the compensation box on the column is measured, the temperature of the metal shell of the box can reach 59 °C, and the temperature of the air inside the box can reach 45 °C. The internal fastener temperature can reach 48 °C. It is obvious that the device with an ambient temperature parameter of 40 ° C cannot meet the requirements, and the device margin with an ambient temperature of 55 ° C is insufficient. Since the most sensitive component of the device is the electronic circuit component, and the operating temperature of the electronic device as an industrial device is generally 25 to 75 ° C, the device temperature is fully considered in consideration of the ambient temperature and a certain margin. The parameters are preferably 60 ° C or higher.

    b. Humidity. In the technical parameters of the products provided by the factory in recent years, the expression of relative humidity is also different. Some expressions are “relative humidity does not exceed 50% at a temperature of 20 ° C, and relative humidity does not exceed 90% at a temperature of 40 ° C”. The expression is "relative humidity does not exceed 90% at a temperature of 40 ° C", and some expressions are "relative humidity does not exceed 80%". According to the situation that the on-column compensation device is used as an outdoor equipment, the above relative humidity requirements are low, especially in the southern part of Jiangsu, where the summer plum rain season is very humid, so the relative humidity parameter should be 95%.

    c. Rain, dust and anti-condensation. The performance of rainproof, dustproof and anti-condensation is related to the structure and sealing of the cabinet. In principle, there are contradictions between the measures to solve the rain and dust prevention and the measures to solve the anti-condensation. In the opposite case, the better the sealing measures, the better the rainproof and dustproof effect, and the worse the effect of condensation inside the box is, because: in the case of not being absolutely sealed, the box is not breathing well. When the temperature and humidity change greatly, the humid air inside the cabinet cannot convect, and it is easy to condense inside the cabinet. Therefore, there should be high technical requirements in the production of the device box. It is necessary to properly grasp the relationship between rainproof, dustproof and anti-condensation, and reasonably improve the protection level of the cabinet, so that these two problems Can be properly resolved.