An Ethernet protector will provide some protection no matter what the signals are.
But one I looked at has a 90V spark over voltage and that will definitely kill your Arduino.
Add series resistance, maybe 220R, to the leads with a 5V Tranzorb from the Arduino inputs to gnd.
Usually I add a Polyswitch and a Unidirectional Tranzorb as then you get protection both ways. This is also a good idea on the DC power input as it will protect from spikes and reverse connection.
https://www.allaboutcircuits.com/te...ient-voltage-suppressors-tvs-an-introduction/
Another thing is to use opto isolated inputs.

 

How is best method to protect outdoor signal from lightning ?

This was the primary question!

 

An Ethernet protector will provide some protection no matter what the signals are.
But one I looked at has a 90V spark over voltage and that will definitely kill your Arduino.
Add series resistance, maybe 220R, to the leads with a 5V Tranzorb from the Arduino inputs to gnd.
Usually I add a Polyswitch and a Unidirectional Tranzorb as then you get protection both ways. This is also a good idea on the DC power input as it will protect from spikes and reverse connection.
https://www.allaboutcircuits.com/te...ient-voltage-suppressors-tvs-an-introduction/
Another thing is to use opto isolated inputs.

Yes... before I was used LoRa with DC supply from charged battery but battery was exploded when hit's by lightning, I think it's not good solution in my case because it's can make personnel hazards not only equipment hazard

 

This was the primary question!

Ok... why if question was spread to another question ?, is that prohibited in this forum ?, if yes I can make new post

 

Here is one opto isolated input

and an output circuit. This drives relays but the optos could be used for FETs or other switch devices.

The Arduino and I/O power supplies are not connected together at all.

 

I don't deal with lightning on a daily basic but I do deal with a close relative, high voltage, high energy inside X-ray/RF/EMI shielded enclosures to control cabinets. We digitize everything and use fiber optic media loops.

 

Lightning suppression is a tricky subject. Absolute protection from a direct strike is impossible! Suppression systems attempt to drain the potential difference in charge BEFORE a stroke occurs or give it a more direct path to ground to prevent associated damage. When a stoke occurs a great deal of high voltage energy may be induced into nearby electrical systems even without a direct strike occurring. In those cases, surge suppression devices or spark gaps are used to drain the high potential before it damages systems. Using grounded shield cables and enclosures can help reduce EMP damage to signal wiring and its associated components.

 

Some use ethernet, some use R-VV cable, not problem with cable but the sensor itself all wire except go to individual sensor is protected with good conduit more better than outdoor cable, about 2.3mm thick PVC pipe, but sensor let's say PIR is attached to the gate, naked without any case, and that wire connected to almost every part of electricity indirectly

Re lightening direct , and the PVC pipe comment
Refer back to a car being struck, its off the ground by at least 30mm, by rubber tyres, yet it gets struck, a 1mm wall PVC pipe will make no difference to lightning,

Again it down to what do you actual want to protect against, a lightening strike or a EM pulse type event caused by lightening or ground potential jump.

If your after real lightening protection, look at EMP protection
https://www.euro-emc.co.uk/products/product-category/electromagnetic-pulse-protection-empp/
look at the size of the filters and the cases they systems are mounted in,

I really don't think you are talking about lightening protection, but lets clarify .

 

Arduno
its designed for a nice benign environment, say 0 to 40 temperature range, how cold will these Arduinos get in winter on an external gate ?

These guys make more rugged versions, but not lightening proof
https://www.rugged-circuits.com/

Regarding switch inputs to arduno
as mentioned above, opto isolation is the way forward, again wont protect against lightening, but a good start.
Put a MOV or other such devices across switch along with the opto , might protect Arduino,

But once again, if switch is hit by a bolt, it will vaporise anyway.

 

Arduno
its designed for a nice benign environment, say 0 to 40 temperature range, how cold will these Arduinos get in winter on an external gate ?

These guys make more rugged versions, but not lightening proof
https://www.rugged-circuits.com/

Regarding switch inputs to arduno
as mentioned above, opto isolation is the way forward, again wont protect against lightening, but a good start.
Put a MOV or other such devices across switch along with the opto , might protect Arduino,

But once again, if switch is hit by a bolt, it will vaporise anyway.

No... not standard arduino, it's Chinese cloned arduino with industrial grade, better than ruggeduino, temperature range is -20 degree celcius to 90 degree celcius, and arduino is placed about 20 meters from sensor, there is arduino bank inside control room, all sensor wire is very very complex, about 19 kilometers of wire in office with 200 meter square area, also not include data center cable, we have more than 250 kilograms of copper inside building ))))))), your answer is not good, that's not my case

 

A real lighting protection system deflects bolt energy to a benign current sink. It's not an simple or easy project for most small industrial sites.
https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2018/intexpsafety/DentonPaper.pdf

 

No... not standard arduino, it's Chinese cloned arduino with industrial grade, better than ruggeduino, temperature range is -20 degree celcius to 90 degree celcius, and arduino is placed about 20 meters from sensor, there is arduino bank inside control room, all sensor wire is very very complex, about 19 kilometers of wire in office with 200 meter square area, also not include data center cable, we have more than 250 kilograms of copper inside building ))))))), your answer is not good, that's not my case

@meowsoft I'm interested as we use a lot of Arduinos,
can you post a link please as to these industrial Arduinos your using,

 

INVALID ANSWER !, PROVIDE ANSWER TO MY PRIMARY QUESTION AND DON'T STALKING !, OR GO AWAY FROM MY POST !!!

@meowsoft you really need to calm down. @andrewmm is a very helpful, engaged, long term member of this community. This isn't your personal advice site. The idea is mutuality. If you aren't willing to contribute to other members from your knowledge why would anyone want to help you?

You once asked how to become a "well known member", this isn't it. You will become well known, but not in the way you want. I know that I am going to start passing on your questions if you are going to treat the forum as an asymmetrical source of free consulting for you while angrily shouting down simple questions from others who help you.

Please think about it.