Lightning protection component selection considerations

Choosing the right lightning protection component is a very important link in the lightning protection design process. It can be divided into switch-type lightning protection components, pressure-limiting lightning protection components and lightning protection devices against over-current and over-heat protection. In practical application scenarios, which lightning protection components should be selected should be analyzed and reasonably selected according to specific applications.

Lightning protection devices installed in series on the line, in the selection of lightning protection devices must first ensure that lightning protection devices can play a protective effect, but also consider whether the lightning protection devices and communication lines match, so in the selection of lightning protection devices When thinking first: discharge current, voltage level, rate matching, interface type, equipotential bonding interference and other factors.

The choice of discharge current level, as far as possible allow lightning protection devices with a large discharge current ability.

The selection of the voltage level, the choice of the maximum operating voltage of the lightning protection device, is determined based on the operating voltage of the communication line. In general, the maximum operating voltage of the lightning protection device must be greater than 1.2 times the operating voltage of the communication line.

The choice of rate matching means that the maximum transmission rate supported by the lightning protection device should be greater than the communication rate of the communication line, otherwise it will cause the communication to stop or increase the bit error rate and affect the normal operation of the communication system.

The choice of interface type, lightning protection device is a series device on the communication line, in order to match the impedance and save the minimum contact resistance (reduce attenuation), you must choose the same type of interface with the communication device, but also pay attention to the line pair match , The coaxial interface should also pay attention to male and female cooperation. After selecting the right interface, the communication leg of the device must also recognize that the communication device is used to match the protection leg of the lightning protection device.

Equipotential leveling and mutual obsession. In order to adapt to the multi-loop integrated lightning protection, many manufacturers have developed integrated lightning protection devices with multi-circuit lightning protection, such as a lightning protection integrated lightning protection device integrating a power supply, a video signal, and a control signal together. . This type of lightning protection device should be internally made equipotential structure, while taking into account the interference of the AC power supply on the video signal.

The lightning protection system is a complex system. The selection of lightning protection devices is the most important link. If the lightning protection components are not selected accurately, the protected devices may be unsafe and their normal operation cannot be guaranteed.