RT97 relay system is installed,The wider the antenna, the wider the area covered.The better the signal.So the antenna is often the highest position in the entire radio coverage area.At this time, there will be a lightning strike effect.It’s a bit like a lightning rod.Lightning protection of the entire system is very important.
First of all, we must first understand how Ray is formed.The highest position on the ground or building,Able to collect a large amount of ground charge,When the amount of charge reaches a certain level,It will be ionized and discharged by humid air.The discharge current is very large,Near short circuit current of high voltage wire,It’s even bigger.After understanding the formation principle of lightning,We will know how to solve the lightning strike problem.(Lightning protection is a systematic project, here we talk about how the relay station system is lightning protection.)
Methods as below:
1, the antenna is set at the secondary height
There is an antenna for mobile communication around the antenna.Or TV sharing antennas, etc.When the RT97 repeater is erecting the antenna,
The antenna is not above or flush with these antennas,Within 50 meters of these antennas,You can receive lightning protection.Because these antennas are installed with lightning protection measures.Ground charged charges have been removed from the lightning rods of these antennas.The charge on the nearby ground is not enough to cause a lightning strike.
2, set up lightning rods
When it is impossible to protect against lightning by other antennas,You can only install the lightning rod yourself.At the top of the metal support rod of the antenna,Weld a metal rod that is about 60 cm long.Use a wire rope with a diameter of 6mm or more to link the metal rod to the ground.Below the ground, link copper rods longer than 2 meters.The copper rod is inserted vertically into the soil.The link of the wire rope is very strong.Welding together is best.The ground resistance is less than 4 ohms.If it is higher than 4 ohms,Need to be in the soil around the copper rod,Evenly into the toner,And poured with concentrated brine.Earth resistance is measured once a year.If the resistance is greater than 4 ohms,Repeat the above actions.The antenna is then mounted on the side of the lightning rod.The height is lower than the downward 45 degree line of the lightning rod.
3, building lightning protection grounding point lightning protection
Is the second kind of trouble?In fact, there is a very practical and easy to use lightning protection method.The construction of modern buildings has been very scientific.Lightning protection is a must-do project.The building was built with lightning protection for the entire building.
Around the building,There are many lightning protection grounding points for the building.And all the grounding points are connected by a steel bar around the building.Even if you don’t see the reinforcement,The building has an obvious grounding sign.Whether it is the steel bars surrounding the building,Or the ground point identified by the grounding,They are used to make lightning protection for the antenna.
Use a 6 mm square single strand copper wire,One end links the antenna support rods,Or a diagonally-drawn wire rope that links the support rods,One end links the lightning protection grounding point of the building.Try to solder as much as possible when linking.If necessary, remove the rust before connecting.Because the grounding effect of the building is very good,So this way is very safe and practical.
Wrong lightning protection method:
Put the lightning protection lead,Connected to metal water pipes, on natural gas pipelines.This is very dangerous.These pipes are eventually buried in the soil.It is grounded.But these pipes are very long,There are so many connectors.As a result, his electrical conductivity is very poor.
The grounding resistance is very large,The current released by the lightning cannot flow into the earth through the pipe.Instead, the earth’s charged charge will collect on the antenna.The vibrator through the antenna wants to release in the air.At this time, the antenna became a lightning rod.very dangerous!
If you are doing a rigorous project,Please use the second method.
If you are a radio enthusiast,Just for testing,There are two other methods that can be used.