LTE outdoor router grounding question

[srluxint]

Hi! I'm willing to build up a network within my residential house which includes outdoor equipment for WAN access. And I'm failing to figure out the best way for me to make it work reliably, especially in terms of lightning (EMI) protection. So let me introduce all the necessary info regarding my setup:

1. We have like 100-200 houses neighborhood, all houses siding one near another, so you may surely say it's not a single house in the middle of the field.
2. Unfortunately I don't have any proper grounding within my house, i.e. there is no somewhat like centralized grounding bus or bar with all devices grounded to it.
3. I have an LTE router kit with PoE powering for outdoor use with a grounding terminal. The manual says I should definitely use it for proper grounding whatever it is. And manual also says that I should use a shielded CAT5E cable to connect the outdoor router to my local indoor network.
4. .. and also the manual suggests that I use a mast for mounting. Which I don't currently have, yet I'm willing to install some short L-shape mast on top of my house wall to get the router somewhat 0.5-1.5 meters above the house roof. It has NO direct connection to earth.

And now the fun part begins. Shielded cable, router itself and a mast should be properly grounded as per my understanding. For the purpose of lightning and other EMI noise protection (weather induced, I don't really expect any extensive industrial radio interference or like). Unfortunately I can't use any professional help because the industry itself is filled with amateurs with no proper knowledge in my specific country. So what should I do? The googling and self-educating part has leaded me to a probable solution:
a) the shielded cable should be grounded from a single side, the outdoor side, as my indoor equipment does not have any grounding at all anyways; also I have surely no idea on how to ground an indoor router with a plastic case and absent ground terminal; so for that reason I use an FTP RJ-45 connector on outdoor side and basic UTP RJ-45 connector on indoor side.
b) as per my router, I simply connect the grounding terminal to the mast with a somewhat 6AWG short solid wire
c) then I set up a local grounding with a specifically designed for burying metal rod and attach it to the house wall with a clamp (pretty much like NEC picture suggests? the one is attached)
d) finally I connect the mast and the rod via another clamp with a 1AWG grounding conductor
e) I definitely should use some discharge/surge protection unit, yet I'm not aware of how to do it correctly

The questions:
1. What flaws does my plan have? What should I fix in it?
2. Should I or should not worry about my grounded mast and antenna acting as lightning rod? Is having lightning rod like this is better than having none at all?
3. What about surge protection unit? Should I use it on a single end near the antenna or should I place it near my indoor equipment too? In latter case, should I ground it to my mast too?

Thank you for your time reading it.

 

[pc1966]

My own view is if your mast is more or less the highest part locally and you see any risk of lightning then it should be grounded to act like a lightning rod should the worst happen and it is hit. Not begin grounded won't make any difference to several MV that has just traversed km of air, it will still be hit and the power will go somewhere. You really want that "somewhere" to be outside in to the ground in a manner that won't start a fire or risk someone in the property being side-flashed as it finds a way to the Earth.

This document (17BM PDF) has a lot of information on lightning protection systems:

https://www.erico.com/catalog/literature/E907W-WWEN.pdf

And this has helpful formulae for estimating earth electrode resistances:

Measurements and Calculations Of Earth Electrode Systems (BS 7430) | EEP

System earthing involves the provision of a connection to the general mass of earth. This connection should have a resistance not greater than that required to operate safety mechanisms to isolate the electricity supply from a fault situation.

electrical-engineering-portal.com

If you can use aluminium tape or wire it is cheaper and less likely to be stolen, but take care with galvanic corrosion if it is in contact with any other metal (copper, brass, stainless steel) and use wither petroleum jelly (Vaseline) or some specific products such as Noalox or these:

Bicon X1 Electrical Joint Compound

Bicon X1 electrical joint compound by Prysmian is designed to prevent galvanic corrosion and to enhance connection in electrical joints. Get yours today online from Jointing Tech

www.jointingtech.co.uk

Oxide Inhibiting Compound

Buy Oxide Inhibiting Compound online from AN Wallis; number one supplier of your earthing, lightning and surge protection needs. Buy now.

www.an-wallis.co.uk

We used A2 stainless threaded rod as earthing rods as they are cheap-ish and easy to get, and with a few nuts & washers easy to terminate tape to them.

You can get surge protection for Ethernet lines, though it is harder to protect PoE due to the DC paths. For example:

Tycon Systems TP-ESP-1000-POE

The Tycon Power ESP-1000-POE is an affordable ethernet surge protector designed to safeguard sensitive equipment from surges caused by lightning and power fluctuations. It has a full metal body for EMI suppression, integral mounting feet, and is compatible with all PoE systems rated up to 57V...

www.msdist.co.uk

Again it has to be well earthed.

 

[srluxint]

My own view is if your mast is more or less the highest part locally and you see any risk of lightning then it should be grounded to act like a lightning rod should the worst happen and it is hit. Not begin grounded won't make any difference to several MV that has just traversed km of air, it will still be hit and the power will go somewhere. You really want that "somewhere" to be outside in to the ground in a manner that won't start a fire or risk someone in the property being side-flashed as it finds a way to the Earth.

This document (17BM PDF) has a lot of information on lightning protection systems:

https://www.erico.com/catalog/literature/E907W-WWEN.pdf

And this has helpful formulae for estimating earth electrode resistances:

Measurements and Calculations Of Earth Electrode Systems (BS 7430) | EEP

System earthing involves the provision of a connection to the general mass of earth. This connection should have a resistance not greater than that required to operate safety mechanisms to isolate the electricity supply from a fault situation.

electrical-engineering-portal.com

If you can use aluminium tape or wire it is cheaper and less likely to be stolen, but take care with galvanic corrosion if it is in contact with any other metal (copper, brass, stainless steel) and use wither petroleum jelly (Vaseline) or some specific products such as Noalox or these:

Bicon X1 Electrical Joint Compound

Bicon X1 electrical joint compound by Prysmian is designed to prevent galvanic corrosion and to enhance connection in electrical joints. Get yours today online from Jointing Tech

www.jointingtech.co.uk

Oxide Inhibiting Compound

Buy Oxide Inhibiting Compound online from AN Wallis; number one supplier of your earthing, lightning and surge protection needs. Buy now.

www.an-wallis.co.uk

We used A2 stainless threaded rod as earthing rods as they are cheap-ish and easy to get, and with a few nuts & washers easy to terminate tape to them.

You can get surge protection for Ethernet lines, though it is harder to protect PoE due to the DC paths. For example:

Tycon Systems TP-ESP-1000-POE

The Tycon Power ESP-1000-POE is an affordable ethernet surge protector designed to safeguard sensitive equipment from surges caused by lightning and power fluctuations. It has a full metal body for EMI suppression, integral mounting feet, and is compatible with all PoE systems rated up to 57V...

www.msdist.co.uk

Again it has to be well earthed.

Thank you for your great answer!

I'm totally agree with you on the idea of having any lightning rod is a better thing than having none at all as per my amateur view. Am I right to assume that having lightning rod doesn't actually increase my overall chances to get hit by a strike? What are possible downsides of installing it?

I'm sorry if the answers to my questions are present in the handbook you've linked above. I've just started reading it.

 

[pc1966]

Am I right to assume that having lightning rod doesn't actually increase my overall chances to get hit by a strike?

Making your building taller / pointier by adding a pole to the upper part has a small effect in increasing the chance of being hit. But if you need that for an antenna or to gain line-of-sight for a microwave link then you pretty much are going to do it anyway.

Actually connecting that pole to a good earth makes no difference to the chances of a hit. As before, if lightning has already crossed km of air on its way down a few metres of stone building is nothing.

What are possible downsides of installing it?

Cost & effort is the main thing. Also you really want your internal power earth to be linked to it as well so when hit you don't see much of a voltage difference within the property (just as shown in the NEC diagram you posted).

Here in the UK you would also be expected to have a type 1+2 surge protection device at you incoming supply point if a lightning protection system is fitted. In reality it is not making a difference to the non-LPS risks, but the assumption in the regulations is an LPS is fitted for a reason (high risk of a hit, or major consequences arising from it) and so you should continue the protection to reduce the magnitude of any surges arising from the lightning find its way out via power lines as well as the dedicated LPS earth. But if you have a high risk of lightning in your area then SPD on the power would be a priority anyway.

You location is just given as "Russia" but that is a big country so I have no idea what sort of risk your region has. Even beyond the average strikes / km^2 statistics, local terrain and nearby objects (e.g. tall church spire, etc) can make significant difference to the risk of a hit.

In some areas, such as the USA, there is a significant risk of liability if not fitted properly and someone claims they suffered as a result. The guide talks about "step potential" which drives the risk of someone standing by the earth rod being injured due to the voltage gradient along the surface of the Earth. Without the LPS they would probably suffer even more, but on fitting it you have taken steps so some care to keep the rod deep and insulate the down-conductor in to the earth, etc, or to keep folk away (e.g. fence, if not already an enclosed garden, etc) should be considered.

Finally think and check before you drive in an earth rod! There might be buried service pipes (water, gas, sewer) or cables in the ground (power, telecoms, etc). If you can hand-dig down a modest size hole (just as for a big fence post) to 1m or so you will probably have cleared or discovered anything, and then can drive down a 2m or so rod in and bury it so the upper is insulated, etc. Also you might find local gov has maps/plans of buried services you can check.