Surge protective device and overvoltage protectors are two commonly used electrical equipment protection devices. They can limit or discharge transient overvoltage in the power system and prevent electrical equipment from being damaged by lightning or other causes. However, their working principles, performance indicators, application scenarios and national standards are all different. This article will compare and analyze surge protectors and overvoltage protectors from these four aspects so that readers can correctly select and use these two protection devices.
Surge Protective Device (SPD) is a low-voltage electrical appliance used in low-voltage distribution systems to limit instantaneous overvoltage and discharge surge current. Its core component is a zinc oxide varistor (Metal Oxide Varistor, MOV), which has nonlinear voltage-current characteristics, that is, when the applied voltage is lower than its threshold, its resistance is very high and almost no current passes; When the applied voltage is above its threshold, its resistance decreases rapidly, passing a large amount of current. In this way, when an instantaneous overvoltage occurs in the power grid, the surge protector will quickly turn on and discharge the overvoltage to the ground line, thereby protecting the subsequent electrical equipment.
Overvoltage Protector (OVP) is a device that can automatically and quickly cut off power. Its core component is a voltage sensor (Voltage Sensor), which can detect voltage changes in the power grid and is connected to a control circuit. When the voltage in the power grid exceeds the set range, the control circuit will trigger a switch to cut off the power supply, thereby protecting the subsequent electrical equipment.
Post time: May-15-2024
