table of Contents
1. Common layout of outdoor LoRaWAN gateway
Two, lightning protection outdoor articles
Three, lightning protection indoor articles
Things to pay attention to include:
4. Schematic diagram of lightning protection equipment installation
1. Installation of antenna feeder arrester
2. GPS antenna lightning arrester
Preface
The location of outdoor LoRaWAN gateways is often in poor conditions. In addition, in order for the gateway to better collect the uplink data sent by the nodes, and to better issue instructions to the nodes, and to cover more nodes, the outdoor LoRaWAN gateways are often used. The gateway is placed in a higher position (as shown in Figure 1), which brings potential thunder and lightning hazards. Lightning may cause damage to the gateway, such as surge damage.
This article describes how to arrange outdoor LoRaWAN gateways to better protect against lightning.
- If you want to know the operating power consumption of the outdoor LoRaWAN gateway, you can also refer to the article " What is the power consumption of the outdoor LoRa gateway RAK7249 when only LTE and LoRa are enabled? ";
- If you want to know how many nodes the LoRaWAN gateway can support, please refer to the article " How to calculate the network capacity of the LoRaWAN gateway ";
- If you want to know how the LoRaWAN gateway connects to the Alibaba Cloud platform, please refer to the article " Two Steps to Connect Your LoRaWAM Gateway to Alibaba Cloud ";
- If you want to know how the LoRaWAN gateway connects to the TTN server, please refer to the article " How to connect the Raspberry Pi gateway to the TTN—Teach you how to connect the Raspberry Pi gateway to the server Part 4 ".
1. Common layout of outdoor LoRaWAN gateway
The common layout of outdoor LoRaWAN gateways is at a higher place in the required area, such as on the roof as shown in Figure 1. Due to the high location, attention should be paid to lightning protection during the layout process.
Lightning protection measures for outdoor LoRaWAN gateways require comprehensive arrangements both outdoors and indoors. Next we will make a specific introduction.
Two, lightning protection outdoor articles
1. The antenna is grounded
It is recommended to install an antenna-fed lightning arrester on the N-type connector of all antennas (LoRa, LTE, Wi-Fi and GPS antennas).
The antenna-fed lightning arrester needs to be grounded reliably. It is recommended to use a 10 AWG or better grounding wire and connect the threaded end of the arrester to the public ground point of the outdoor building.
When buying an antenna-fed lightning arrester, you need to pay attention to the adapter type of the interface (the interface is divided into male and female). The adapter type needs to be compatible with the antenna and the connector on the gateway housing .
2. The gateway is grounded
To ensure reliable grounding of the gateway, it is recommended to use another 10 AWG or better grounding wire to connect the grounding screw at the lower right corner of the gateway housing to the public grounding terminal of the outdoor building.
If it is the RAK72XX commercial gateway, the LoRaWAN gateway has a built-in surge protection system (GDT + anti-surge resistor), therefore, no additional Ethernet lightning protection is required, only grounding is required.
Three, lightning protection indoor articles
The main strategy for indoor lightning protection is to set up an indoor surge protection system.
In order to protect the indoor equipment and circuits connected to the LoRa gateway, you need to install an SPD lightning arrester with an Ethernet interface at the entrance where the network cable enters the room. All indoor equipment should be protected by this lightning arrester.
Make sure to connect the ground wire end of the arrester to a proper building ground point, so that your PoE injector and network switch/router can be protected from surges.
Things to pay attention to include:
(1) Ensure that all antennas (the lightning arrester grades of GPS antennas are different, as shown below), gateway housing and Ethernet SPD are reliably connected to the grounding point.
(2) Make sure that you provide a well-grounded pole with a lightning rod for the LoRa antenna and gateway equipment.
(3) The lightning rod should be high enough, and all equipment should be protected by the 45 degree angle of the lightning rod.
For the outdoor and indoor parts of the surge protection system, see Figure 2 for the installation example. Figure 2 is a schematic diagram of the on-site deployment (including grounding rods) of the RAK7249 outdoor commercial gateway RAK7249.
4. Schematic diagram of lightning protection equipment installation
1. Installation of antenna feeder arrester
As shown in Figure 3, the antenna-fed surge protector is connected in series between the antenna feeder and the transceiver equipment to prevent and reduce the damage to the transceiver equipment due to induced lightning, surge overvoltage and surge overcurrent. It is suitable for 50 ohm radio frequency system with working frequency of DC-2700MHz and transmission power less than 200W.
2. GPS antenna lightning arrester
The GPS antenna lightning arrester is a surge protection device connected between the GPS antenna and the GPS receiver to prevent and reduce the damage to the transceiver equipment due to induced lightning, surge overvoltage and surge overcurrent.
Such as the GPS antenna lightning arrester of Rui Ke Hui Lian. It uses a high-pass filter, which can effectively suppress low-frequency interference. The DC power supply circuit is protected by a transient voltage suppression device (TVS) and a gas discharge tube (GDT). Figure 4 is a schematic diagram of its installation.
Conclusion
This article introduces the lightning protection measures that need to be taken during the actual use of outdoor LoRaWAN gateways, including indoor measures and outdoor measures. I hope it will be helpful to those who use outdoor LoRaWAN gateways for the first time.