I am looking for a way to ground (and hopefully surge/EMI/RFI protect) properly an ATL and its corresponding indoor LAN. The planned setup is pretty standard:
ATL on a metal mast -- [building wall] -- hAP ac³ indoors -- LAN
The "--" connections use U/FTP Cat 5e cable. The height of the mast is 5-6 m (which is significant and could probably attract lightnings). Right next to the building wall (outdoors) there is other metal construction which is in physical contact with the mast. That whole metal construction's base is cemented in the ground (i.e. grounded, not quite scientifically, but that is all we have). The total Ethernet cable length between the ATL and the hAP is about 15 m.
The hAP ac³ and (most of) the LAN devices are back-UPS powered. That back-UPS has Ethernet In/Out port but it does not support PoE. There are no grounding terminals anywhere in the building, so for devices indoors we rely on Schuko sockets and the neutral line (N) being properly grounded/earthed by the electrical company. Unfortunately, the two MikroTik devices have no Schuko plugs. (A) [referred below]
Information I have so far:
The user manual saying:
The grounding connector is simply a hole with a thread in the metal plate of the ATL. There is grounding wire packed with it, not even a bolt with proper thread. For some reason this hole is *not* visible on the rendered image of the ATL. It is near the SIM card slot, i.e. under the plastic cover.Use a POE injector and proper grounding, this device has a specially-designed grounding connector under the port cover. Recommended using shielded Cat5/6 cable.
The dark-gray box with the cylindrical hole in it is actually white in reality. It is a rubber sealing through which the Ethernet cable passes (quite tightly). There are no holes or openings for any other cables whatsoever, so it is not clear (or documented) at all how exactly one is supposed to ground properly the ATL.
Information from support:
However, considering ATL's actual design, it is physically impossible to use a MikroTik GESP simply because it's RJ45 cannot pass through the rubber sealing of the ATL. The GESP+POE is not an option either because of (A).There is a separate ground connector on the ATL under the port cover. You need to connect the ground pin to the mast, that is grounded.
If the mast is in contact with the ground and is not painted, you should not ground it separately.
GESP supports PoE passthrough. You can use it on both ends of the ethernet cable between hAP and ATL to protect from lightning or surge damage. ( If you do not want to use PoE-Out, you can get GESP+PoE-In for the indoor side)
At first sight, it seems the only option is to pass a thin wire through ATL's rubber sealing together with the Ethernet cable and put it in contact with the mast. Perhaps, I could actually use the ground wire of the cable itself, screwing it to the grounding port, pass it through the sealing, then on the mast. That would ground both the ATL and the cable shielding. This, however, equals zero surge protection.
Another possibility is:
ATL -- GPeR + GPeR IP67 Case -- GESP -- [building wall] -- hAP ac³ indoors -- LAN
However, I am questioning the benefit of this option - not only because of its added price but also because adding more (otherwise unnecessary) components along the Ethernet cable normally reduces its throughput. Honestly, I am also questioning the overall protection the GESP could provide, considering nothing can save the ATL in case of a direct lightning strike and in case of a thunderstorm I would surely unplug the cables on the indoors side.
What would you do?
Please share your experience, thoughts and advises.