1. The low-voltage electric in the distribution box is composed of disconnector, DC contactor, residual current posture protection equipment, low-voltage capacitor and meter. The relativity of all normal working standards is stipulated: The limit of the nearby vapor temperature is not more than 40 °c; the average value of the nearby vapor temperature for 24 hours is not more than 35 °c; the Lower Limit of the nearby vapor temperature is not less than-5 °C OR-25 °C. The distribution box runs in the open air, not only does its exposure to the sun's rays cause the temperature, but it also causes its own calorific value. Therefore, in the hot summer season, the human body temperature in the box is likely to keep above 60 °C, the temperature of the geographical environment specified by such appliances at the moment will cause common problems caused by overheating of household appliances and electronic devices in the distribution box.
2. Common problems caused by output during the renovation, due to the large number of distribution boxes and tight construction period, the delivery time of distribution boxes must be urgent and the quantity of low-voltage electricity must be large, thus resulting in a situation where the requirements for output are not stringent, this has resulted in a number of products that have caused common problems shortly after the funds were allocated to run.
3. Common problems caused by improper selection of distribution box due to improper selection of DC contactor capacity in production and processing, installation of DC contactors with the same capacity in control circuits for different working lines, and did not take into account the three-phase load imbalance, and can not work out a part of the line DC contactor current in all normal selection specifications most of the model, a current selection, thus leading to hot weather when the operation of DC contactors damaged.