1.1 Failure caused by the influence of ambient temperature on low-voltage electrical appliances If you are familiar with the distribution box, you should be very clear about the internal structure. Low-voltage electrical equipment in the distribution box consists of fuses, AC contactors, residual current protection devices, capacitors, and meters.
These low-voltage electrical appliances are designed and manufactured in accordance with GB1497 "Basic Standards for Low-Voltage Electrical Appliances", and the normal working conditions of these components are regulated accordingly:
(1) The upper limit of the ambient air temperature inside the explosion-proof distribution box does not exceed 40 °C;
(2) The average air temperature around the component for 24 hours does not exceed 35 °C;
(3) The lower limit of air temperature around the component is not lower than -5°C or -25°C.
The explosion-proof power distribution box transformed by the rural network is running outdoors, so this will not only make the explosion-proof power distribution box subject to direct sunlight and generate high temperature, but at the same time, the explosion-proof power distribution box will also generate heat in its operation, so in the midsummer high temperature season, explosion-proof power distribution The temperature inside the cabinet will reach above 60°C, and the temperature at this time will greatly exceed the ambient temperature specified by these appliances. Therefore, malfunctions due to overheating of electrical components in the distribution box will occur.
1.2 Failure caused by product quality At the time of the renovation of rural power grids, the number of explosion-proof distribution boxes due to demand was large and the construction period was short. Explosion-proof switchgear factories needed urgent and numerous supply times for low-voltage electrical appliances. These numerous reasons caused the manufacturing units. The phenomenon that the requirements for product quality are not strict have caused some products to fail shortly after they have been put into operation. If some types of AC contactors were put into operation shortly after the distribution box was put into operation, they could not be operated because the contactor closing coil was burned out.
1.3 Failure caused by improper selection of electrical equipment in the explosion-proof distribution box Because the inappropriate selection of AC contactor capacity during manufacturing, AC contactors of the same capacity are installed for different outlet loops, and the imbalance of the three-phase load is not considered. However, the current rating of some of the outlet contactors could not be increased on the basis of the normal selection model, and the selection of a current level was improved, resulting in the occurrence of AC contactor burnout during summer hot season operation.
If you know these reasons, then you should choose a good quality explosion-proof distribution box when the product is purchased; make good use of the heat dissipation measures of the distribution box to avoid unnecessary losses.
These low-voltage electrical appliances are designed and manufactured in accordance with GB1497 "Basic Standards for Low-Voltage Electrical Appliances", and the normal working conditions of these components are regulated accordingly:
(1) The upper limit of the ambient air temperature inside the explosion-proof distribution box does not exceed 40 °C;
(2) The average air temperature around the component for 24 hours does not exceed 35 °C;
(3) The lower limit of air temperature around the component is not lower than -5°C or -25°C.
The explosion-proof power distribution box transformed by the rural network is running outdoors, so this will not only make the explosion-proof power distribution box subject to direct sunlight and generate high temperature, but at the same time, the explosion-proof power distribution box will also generate heat in its operation, so in the midsummer high temperature season, explosion-proof power distribution The temperature inside the cabinet will reach above 60°C, and the temperature at this time will greatly exceed the ambient temperature specified by these appliances. Therefore, malfunctions due to overheating of electrical components in the distribution box will occur.
1.2 Failure caused by product quality At the time of the renovation of rural power grids, the number of explosion-proof distribution boxes due to demand was large and the construction period was short. Explosion-proof switchgear factories needed urgent and numerous supply times for low-voltage electrical appliances. These numerous reasons caused the manufacturing units. The phenomenon that the requirements for product quality are not strict have caused some products to fail shortly after they have been put into operation. If some types of AC contactors were put into operation shortly after the distribution box was put into operation, they could not be operated because the contactor closing coil was burned out.
1.3 Failure caused by improper selection of electrical equipment in the explosion-proof distribution box Because the inappropriate selection of AC contactor capacity during manufacturing, AC contactors of the same capacity are installed for different outlet loops, and the imbalance of the three-phase load is not considered. However, the current rating of some of the outlet contactors could not be increased on the basis of the normal selection model, and the selection of a current level was improved, resulting in the occurrence of AC contactor burnout during summer hot season operation.
If you know these reasons, then you should choose a good quality explosion-proof distribution box when the product is purchased; make good use of the heat dissipation measures of the distribution box to avoid unnecessary losses.
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