====== Surge Protection ======

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.

===== When do you need it? =====

  * Receiver outdoors, switch/router indoors → plan for a surge protector.
  * Fully indoor installation (e.g. receiver on the windowsill behind glass): not needed.
  * A surge protector guards against **induced** surges (nearby lightning, static build-up). It does not protect against a direct strike – that would require a proper lightning protection concept from a professional.

===== What is at risk? =====

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.

===== Device =====

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** |

===== Installation =====

  * **Position:** inline in the outdoor run, **before the switch** – i.e. at the indoor end of the cable, as close as possible to where it enters the building. With several outdoor runs, each run gets its own surge protector.
  * **Grounding (mandatory):** connect the grounding terminal with **≥ 4 mm² copper wire** (green/yellow) to protective earth / equipotential bonding (PE). **Without grounding the surge protector is useless**, because the diverted surge has nowhere to go. The wire has to be bought separately.
  * **Outdoor connectors:** keep them protected (outdoor box / covered), cable entries facing down, add drip loops – then connectors outside are uncritical.

===== See also =====

  * [[en:faq]] – PoE vs. USB power, jumper settings
  * [[en:hardware:setups|Hardware Setups]] – PoE variants (802.3af / passive)
  * [[en:hardware:antennas|External Antenna]] – outdoor mounting with an external antenna