The use of voltage protection devices greatly reduces the harm of over-voltage or under-voltage to circuit and electric load. It is equivalent to a small intellectualized switching protection device, which is mainly used in the circuit with current and voltage less than 63A. It is an important protection device for household housing. The use of over-voltage and under-voltage protectors is the improvement of people's awareness of electricity safety, and the state has also formulated the relevant norms "Code for Electrical Design of Residential Buildings". However, many consumers do not know what to pay attention to when choosing the protector. In view of this problem, I would like to give you some suggestions.

1. When choosing overvoltage and undervoltage protection devices, try to choose products produced by regular manufacturers. The products produced by regular manufacturers are guaranteed first of all, and the after-sales service is relatively good.

2. When choosing and purchasing, pay attention to the circuit parameters of the product, such as the rated voltage and current of the applicable circuit, to ensure that the product is connected to the power supply and can work normally.

3. Choose the protector with delay function as far as possible. The main function of delay function is that when the power supply is over-voltage or under-voltage, the protector with delay function will make a certain timing. If the voltage is still under-voltage or under-voltage after the timing, the circuit breaking will be carried out. This way can prevent instantaneous over-voltage or under-voltage. When the power supply voltage returns to normal, the delay function can effectively avoid the impact of the load caused by the instantaneous normal voltage.

4. Choose products with long service life. At present, the mechanical life of self-repetitive under-voltage protector can reach millions of times, and the electromagnetic life can reach tens of thousands of times. For users, it is not only practical, durable and inexpensive that matters.

The voltage protection devices is a kind of low-voltage electrical apparatus. Its function is to protect the circuit or electric load when the circuit is under-voltage or over-voltage. The sales of over-voltage and under-voltage protectors are increasing year by year. The main reason lies in the improvement of people's awareness of power security and the protection of power load. A good product is very important for the choice of materials, and the product is no different.

1. Selection of Shell Materials
Generally, the shell of this product is made of flame retardant, heat-resistant and cold-resistant polymer insulating materials.

2. Selection of relays
The voltage protection devices adopt magnetic retaining relay, which can better realize on-off for circuit.

3. Processor Selection
The processor uses a single-chip computer with high speed processing and low power consumption.

4. Selection of Indicators
The indicator lamp is a light-emitting diode with high durability and long service life.

5. Selection of Connecting Conductors
The conductor of this overvoltage and undervoltage protection devices generally adopts large diameter copper wire, large diameter copper wire, not only has strong conductivity, but also has strong resistance to large current.

6. Other electronic components
Electronic components include resistors, capacitors, chips, diodes and triodes. Generally, electronic components with long service life and high reliability are selected.

In order to make the performance of overvoltage and undervoltage protection devices reliable and stable, it is very important to select excellent materials, and the price of this product is relatively high.