The function of the overvoltage and undervoltage protector is to automatically disconnect when the overvoltage and undervoltage in the line exceed the specified value, automatically detect the line voltage, and automatically close when the voltage in the line returns to normal. It is mainly used for the protection of overvoltage, undervoltage, phase failure and zero line failure in household and shopping malls distribution lines. If the voltage in the home is too high or too low, it is easy to burn out the electrical appliances. For example, if the voltage exceeds the working voltage range of the electrical appliances, the electrical appliances will heat up and burn out easily, causing electrical fire.

Self-resetting overvoltage and undervoltage protector is applicable to users or loads with single-phase AC voltage of 220V, frequency of 50Hz, rated working current of 60A and below. As the protection of single-phase line overvoltage and undervoltage caused by neutral line fault to single-phase electrical equipment. It is mainly used for the protection of the incoming line of residential household distribution box or the distribution line that needs to protect single-phase electrical equipment.

When selecting the overvoltage and undervoltage protector, pay attention to the functional parameters of the product, for example, we should know the voltage and current of the product. You can choose the current of the product according to the current of the total switch of the circuit. Generally, the rated current of overvoltage and undervoltage protection is greater than or equal to the rated current of the main switch. For example, if the main switch of the air switch is C 63, we can choose C63 overvoltage and undervoltage protector. The main brake of the air switch is C40, and we can choose C40 overvoltage and undervoltage protector.

When selecting the overvoltage and undervoltage protector, you'd better check the authenticity of the product through the anti-counterfeit label on the product to avoid purchasing fake and inferior products. When purchasing overvoltage and undervoltage protector, we also need to pay attention to whether the product has 3C certification mark, certificate of conformity, etc.

When selecting and purchasing products, we also need to pay attention to the workmanship, materials, functions, etc. of the products. For example, we should carefully observe whether the marks on the product appearance are clean, whether the product surface is rough, whether there are burrs, etc. When purchasing the over-current and under-voltage protector, you should also pay attention to its capacitance and resistance, whether the capacitance is a high voltage withstand type product, and whether the resistance is a high energy voltage sensitive product.