Selection of Signal SPD Lightning Protection Equipment

When it comes to the use of lightning arrester, many people lack a correct understanding of some of the parameters of the lightning arrester. Coupled with the increasing frequency of thunderstorms and the widespread use of electronic products, many users have encountered many problems in choosing lightning protection products, which can lead to ineffective protection of equipment and create safety hazards. So, what should we pay attention to when choosing a lightning arrester? How should we choose?

Signal SPD lightning arrester equipment is generally divided into audio, video, network, control, and two-in-one or three-in-one categories. When choosing a lightning arrester, first of all, we must ensure that the lightning arrester can provide protection. At the same time, we should also consider the matching problem between the lightning arrester and the communication line. Therefore, when selecting a signal lightning arrester, we should mainly consider the discharge current, voltage level, rate matching, interface type, equipotential connection, and mutual interference.

1. Selection of Discharge Current Level for Thunder Protection Device Equipment

In the allowed range, we should choose a lightning arrester with a larger discharge current capacity as much as possible (some signal lightning arresters have two-level protection inside and have a larger current carrying capacity, such as 5~10KA; while some signal lightning arrester only has one-level protection, and the current carrying capacity is smaller, such as only 0.5KA).

2. Selection of Voltage Level for Thunder Protection Device Equipment

The selection of the highest working voltage of the signal lightning protection device is determined based on the working voltage of the communication line. Generally speaking, the highest working voltage of the signal lightning arrester must be greater than 1.2 times the working voltage of the communication line.

3. Selection of Rate Matching for Thunder Protection Device Equipment

The highest transmission rate supported by the signal lightning arrester should be greater than the communication rate of the communication line. Otherwise, the communication will be interrupted or the error rate will increase, affecting the normal operation of the communication system.

4. Selection of Interface Type for Thunder Protection Device Equipment

The signal lightning protection device is installed in series on the communication line. In order to match the impedance and maintain the minimum contact resistance (reduce attenuation), it is necessary to choose the same type of interface as the communication device. At the same time, we should also pay attention to the pairing of line pairs, and for coaxial interfaces, we should also pay attention to male and female matching. After selecting the interface, we need to confirm that the communication pins used by the communication device match the protection pins of the lightning arrester during installation.

5. Equipotential Connection and Mutual Interference for Thunder Protection Device Equipment

In order to adapt to the comprehensive lightning protection of multiple circuits, many domestic lightning protection manufacturers have developed integrated lightning arresters with multi-circuit lightning protection, such as comprehensive video lightning protection device equipment that provides lightning protection for power supply circuits, video signal circuits, and control signal circuits at the same time. This kind of lightning arrester should have an equipotential structure inside and should consider the interference of AC power supply on the video signal.