A receiver mounted outdoors (balcony, railing, mast) is usually powered via PoE, which means an Ethernet cable runs from outside straight to a switch or router indoors. Thunderstorms in the area can induce voltage spikes on such outdoor cable runs, damaging the connected network equipment. An Ethernet surge protector (surge arrester / voltage limiter) diverts these spikes to earth before they reach the devices inside.
In short: one surge protector per outdoor cable run, installed inline into the LAN cable before the switch, and it must be grounded – without grounding the device does nothing.
A surge induced on the outdoor cable travels down the line and can destroy whatever is connected to it. There is no guarantee the receiver itself survives – but at ~€20 it is cheap to replace, and the same goes for a PoE injector (~€20). The main financial risk sits at the indoor end of the cable: a PoE switch (€100 and up) feeding an unprotected outdoor run can get fried, and in the worst case the damage does not stop there – other devices on the network can be hit as well.
A proven option is the Ubiquiti ETH-SP-G2 (Ethernet Surge Protector, approx. €13):
| Property | ETH-SP-G2 |
|---|---|
| Connection | 2× RJ45, installed inline into the LAN cable |
| PoE | passed through – 802.3af power for the receiver keeps working |
| Data rate | Gigabit-capable (the receiver only uses 100 Mbit anyway) |
| Mounting | weatherproof, suitable for outdoor installation |
| Grounding | screw terminal – grounding wire is not included |