The distribution box is a large number of parameters on the data, which is generally composed of low-voltage forest. According to the electrical wiring, the switchgear, measuring instruments, protection appliances and auxiliary equipment are required to be assembled in closed or semi closed metal cabinet or on the screen to form a low-voltage distribution box. In normal operation, the circuit can be turned on or off by means of manual or automatic switch.
Faults caused by the influence of ambient temperature on low-voltage electrical appliances:
The low-voltage electrical appliances in the distribution box made in distribution box manufacturers are composed of fuses, AC contactors, residual current operated protectors, capacitors and meters. The upper limit of ambient air temperature shall not exceed 40 ℃; the average value of ambient air temperature for 24 hours shall not exceed 35 ℃; the lower limit of ambient air temperature shall not be lower than - 5 ℃ or - 25 ℃.
The distribution box of rural power grid transformation operates outdoors. It not only generates high temperature by direct sunlight, but also generates heat in operation. Therefore, in the hot summer season, the temperature in the box will reach more than 60 ℃, which greatly exceeds the specified ambient temperature of these electrical appliances
Failure caused by product quality:
During the transformation of rural power grid, due to the large number of distribution boxes needed and the short construction period, the distribution box factory needed a large number of low-voltage electrical appliances, which resulted in the phenomenon that the requirements for product quality were not strict, resulting in the failure of some products shortly after they were put into operation. For example, some models of AC contactors cannot operate because the closing coil of contactors is burnt out soon after the distribution box is put into operation.
Faults caused by improper selection of electrical appliances in distribution box:
Due to improper selection of AC contactor capacity in manufacturing, 220v ac contactor with the same capacity is installed for different outgoing circuits, and the imbalance of three-phase load is not considered, so it is not possible to improve the selection of current level of some outgoing contactors on the basis of normal selection model
The distribution box has the characteristics of small size, simple installation, special technical performance, fixed location, unique configuration function, not limited by the site, relatively common application, stable and reliable operation, high space utilization, less land occupation and environmental protection effect. It is the control center to command all kinds of components in the power supply line to reasonably distribute the power, the control link to reliably receive the upper power supply and correctly feed the load power, and the key to obtain the user's satisfaction with the power supply quality. Improving the operation reliability of power distribution box is the goal of creating high quality project.
Zhejiang Xiyiyi Electrical Equipment Co., Ltd