What Are The Models And Specifications Of Surge Protectors?
surge protective device are essential for protecting equipment from damage caused by overvoltage. There are many types and specifications of surge protectors, each with different applications. Let's take a closer look:
1. Operating Voltage Type
When the surge voltage reaches a certain value, the characteristic impedance becomes low. This type of surge protector typically uses components such as galvanic discharge tubes and thyristors. Its main characteristic is strong charging and discharging capability, but its disadvantage is relatively high residual voltage, typically 2-4kV.
2. Voltage Limiting Type
When there is no surge, the characteristic impedance is generally high. As the current and voltage increase, the characteristic impedance continuously decreases. This type of surge protector is also very common, typically using varistors and suppression resistors as components.
3. Combined Type
The combined type is essentially a combination of the two models mentioned above. When using voltage-limiting components, the response time to current is shorter. During maintenance after a lightning strike, it handles the surge current. If a significant lightning overvoltage occurs, all the fuses in the first-stage circuit will burn out, at which point the second stage will provide overvoltage protection.
Additionally, surge protection device often feature both operating voltage switching type and voltage-limiting type characteristics. However, the combined approach is not as good as the independent type, and it is also more expensive.
