Similarities and Differences between Signal SPD and Power SPD

When it comes to surge protection, there are two types of SPDs (Surge Protective Devices) that are commonly used in homes and businesses: Telecommunication SPD and Power Supply SPD. While both of these devices are designed to protect electrical equipment from power surges, they differ in both their functionality and application.


Despite their differences, both telecommunication SPD and power supply SPD perform the same basic function – they protect electrical equipment from power surges. They both employ similar technologies to detect and divert the excess electrical energy away from sensitive equipment, thus preventing damage caused by overvoltage spikes.


Significant difference between the two is the amount of voltage they can handle. Telecommunication SPDs usually have a lower voltage rating than power supply SPDs, as they are designed to handle lower voltage surges typically caused by lightning strikes, whereas power supply SPDs are designed to handle surges caused by huge power outages.

Additionally, the installation of the two types of SPDs is different. Telecommunication SPDs are typically installed near sensitive equipment to provide protection from electrical surges that travel along their communication lines. Power supply SPDs are generally connected directly to electrical circuits and mounted on the service panel to provide whole house surge protection.

In conclusion, while there are some differences between telecommunication SPD and power supply SPDs, they both serve the same purpose of protecting electrical equipment from power surges. Choosing the right type of SPD depends on the specific needs of your equipment and the environment in which it operates.

Working principle of signal surge protection device

When the surge voltage is applied to the input terminal of the protection circuit of signal surge protection device, the transient suppression diode (TVS) with the fastest response will act first;

By selecting appropriate coupling element parameters, the signal surge protection device changes the line design so that the voltage drop on L2 plus the voltage drop on TVS will reach the breakdown voltage of the metal oxide varistor (MOV) as the discharge current increases before the transient suppression diode may be damaged., at which point the MOV starts to discharge;

Similarly, as the discharge current increases further, the voltage drop on L1 plus the breakdown voltage of the MOV reaches the action voltage of the gas discharge tube (GDT), and finally a larger surge current is released by the GDT.


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