How to protect explosion-proof surveillance cameras from lightning outdoors?

All electronic products outdoors must consider the issue of lightning protection, especially special monitoring such as explosion-proof surveillance cameras, must be foolproof, so it must have the function of lightning protection outdoors. So how do we do lightning protection work?   Whether it is a hydroelectric power plant, a thermal power plant or a wind power plant, or even a petrochemical or nuclear power plant, in order to meet the needs of a large monitoring coverage, the monitoring system will set up cameras at certain commanding heights or in open areas. A lightning strike creates an unavoidable risk.   There are generally two lightning protection methods in the security monitoring system of the energy industry, one is grounding, and the other is lightning protection. Grounding is an important measure to protect people, equipment and power supply, and it is an indispensable security measure. Lightning protection is determined according to the installation environment and requirements of the video surveillance system. Although it is not necessary, the importance of grounding and lightning protection in the security monitoring system of the energy industry cannot be ignored because grounding and lightning protection are mutually cooperative mechanisms.       Monitoring front-end grounding and lightning protection measures   1. Outdoor cameras should be equipped with lightning rods, and independent grounding pipelines should be used to isolate the power and image signals of the monitoring equipment to avoid interference current and damage to the line. The lightning rod should be erected higher than the camera, and within the virtual three-dimensional cone of 45-60 degrees downward from the tip of the lightning rod, which is the safe range of the camera. When the lightning rod is installed, it should be insulated from the steel structure that fixes the camera.   2. The grounding of the camera front-end equipment should be concentrated on a grounding bus in the terminal part, so that the grounding of the entire monitoring front-end equipment can meet the requirement of no potential difference to the ground, otherwise it may cause a potential difference to the ground loop and cause the equipment to burn.   3. The grounding wire of the indoor front-end camera should be connected to the grounding terminal of the shared end, and a non-fuse circuit breaker and a leakage circuit breaker with suitable capacity should be installed on the power supply end of the front-end equipment. Avoid damage to the device by induction or conduction lightning.   4. After the grounding of the outdoor camera is completed, the test grounding resistance is less than 10Ω, and the three-point impedance test should be carried out according to the standard for the installation of the grounding rod.   Grounding and lightning protection of the transmission part   1. Due to the long transmission distance and low voltage resistance of some monitoring signals in the energy industry, the equipment is easily damaged by the intrusion of induced lightning and conducted lightning current. In order to transmit the lightning current from the signal transmission line to the ground, the cables should be equipped with surges. When designing the image signal transmission cable, the protector must consider the transmission rate of the signal and the balance and grounding of the voltage to avoid the intrusion of inductive lightning.   2. Outdoor transmission and cables should be well grounded, and the grounding resistance must be less than 10Ω.   3. For overhead self-sustaining signal or power cables, the self-sustaining steel cable should be connected to the ground with a ground wire in the fixed section.   4. The control signal transmission line adopts the cable with isolation and shielding function.   5. The cables of the transmission part should be buried as far as possible in the line erection. When the environmental conditions do not permit, the shortest distance can be used to avoid the intrusion of induction lightning caused by the reduction of the withstand voltage.   Monitoring terminal grounding and lightning protection   1. In the security monitoring system, the lightning protection measures of the monitoring terminal should be cautious, and protection measures such as various possible types of lightning strikes, potential difference to the ground loop, and power supply surges should be considered.   2. The building where the monitoring terminal is located should be equipped with lightning protection system, grounding grid and grounding terminals.   3. Various metal pipelines of the monitoring terminal should be grounded and connected to the grounding device together. When the cable enters the terminal room, the metal outer sheath of the cable and the steel cable part of the self-supporting cable should be connected to the ground terminal.   4. Indoor terminal transmission and cables should have better grounding, and the grounding resistance must be less than 10Ω, but the lower the impedance to ground, the better.   The above are the basic and effective methods of grounding and lightning protection for monitoring systems in the energy industry. Although they are not as strict as national norms or standards, if the construction details of grounding and lightning protection are carefully handled, it should be regarded as an effective lightning protection method.