Lightning Protection for Coaxial Cables
Coaxial cables are frequently used for antenna signals (satellite, cable TV). Since antennas are often mounted on roofs or masts, they are directly exposed to the risk of lightning strikes.
Functionality: A lightning protection module for coaxial cables, often referred to as a surge protector or lightning arrestor, is inserted into the signal line between the antenna and the end device (e.g., router or receiver). Its main task is to immediately discharge an incoming surge. ⚡️
Technology: Most of these modules use a gas discharge tube or a special diode. During normal signal flow, these components act like an open switch. However, as soon as a surge occurs, their resistance drops abruptly to almost zero. The lightning current is thus diverted from the signal line to the grounding before it can reach the connected devices.
Installation: Installation is simple. Mount the lightning protection as close as possible to the point where the cable enters the building and connect it to a reliable grounding source - for example, to the potential equalization in the basement or a separate grounding rod. Without proper grounding, even the best lightning protection is ineffective.
Lightning Protection for Ethernet Connections
Ethernet connections (LAN cables) in buildings, between buildings, or in outdoor areas are susceptible to surges. Longer cable runs are particularly dangerous, as they act as an "antenna" for electromagnetic interference.
Functionality: A lightning protection module for Ethernet cables, also known as a data line surge protector, is installed into the network connection. It protects all eight wire pairs of the cable. 🌐
Technology: Similar to coaxial cables, these modules consist of components (e.g., Transil diodes) that allow the data signal to pass during normal operation. Once the voltage exceeds a certain threshold, they activate and divert the excess energy to the ground.
Installation: Professional grounding is crucial here as well. The lightning protection is installed between the cable coming from outside and the end device (e.g., switch, router). Ideally, mount it on the exterior wall of the building or in the server room as close as possible to the entry point. For networks between two buildings, lightning protection must be installed and grounded at both ends.
Why Both are Important
Comprehensive protection involves securing both coaxial and Ethernet connections. While a coaxial line can cause damage to the router or receiver, a surge in the Ethernet line can destroy your entire network infrastructure, from switches and routers to servers. Lightning protection is a comparatively small investment to avoid significant financial damage.