Lightning is a natural phenomenon that carries both high-energy low-frequency components and highly permeable high-frequency components. It can cause significant damage to electronic equipment in two main ways: first, by directly transmitting the energy through metal pipelines or grounding lines; second, by inducing electromagnetic pulses along the path of lightning discharge, which can couple into metal conduits or grounding systems and cause surges that damage devices. Most of the damage caused by lightning is due to this induction effect.
For electronic information systems, the primary threat comes from the coupling energy of lightning electromagnetic pulses (LEMP) and the transient surges generated through three main channels: metal pipeline channels (such as power lines, signal cables, and antenna feeders), ground channels (ground potential backflash), and space channels (electromagnetic radiation). Among these, the surge on metal pipelines and the ground potential backflash are the most common causes of system failure. The most visible form of damage is often seen on power lines, making them a key focus for lightning protection strategies.
Lightning protection is a systematic approach because lightning can enter an electronic system through various paths. The core principles of lightning protection are venting and balancing. Venting involves discharging the energy of lightning and LEMP into the ground, following a hierarchical principle to ensure that as much energy as possible is dissipated before it reaches the system. This process is based on the concept of lightning protection zones (LPZs), which divide the environment into areas depending on how sensitive they are to lightning and electromagnetic interference.
The LPZOA zone includes objects that may be directly struck by lightning, while LPZOB is an area where direct strikes are not possible but the electromagnetic field remains strong. LPZ1 and subsequent zones are designed to further reduce the current and electromagnetic field strength. The higher the zone number, the lower the expected interference. Properly defining these zones is essential for implementing shielding, grounding, and equipotential bonding measures.
Balancing refers to maintaining equal potential across all parts of the system to prevent dangerous voltage differences during transients. This is achieved through equipotential bonding, which ensures that all conductive components—both active and passive—are at the same potential. A reliable grounding system, along with bonding conductors and surge protectors, helps create a stable equipotential region quickly during lightning events.
The lightning protection system consists of three main components: external protection, transition protection, and internal protection. External protection includes lightning rods, down conductors, and grounding systems that divert most of the lightning energy underground. Transition protection uses shielding, proper wiring, and grounding to block induced surges. Internal protection involves equipotential bonding and overvoltage protection to limit the voltage within safe levels.
A lightning arrester, also known as a surge protector or voltage limiter, plays a critical role in protecting power lines from surges. Its main function is to maintain a consistent voltage between its terminals and dissipate excess energy. Key technical parameters include the rated voltage, current carrying capacity, and throughflow capability, which determines how much lightning current it can handle. Lightning arresters are categorized based on their use: those for direct lightning strike protection (using 10/35 μs waveforms) and those for indirect protection (using 8/20 μs waveforms).
Choosing the right lightning protection device depends on the specific needs of the system and the location of the protected equipment. For example, in areas where direct strikes are likely, such as LPZOA, a higher current capacity is required. In later zones like LPZ1, the requirements are less severe, and the arrester must be carefully selected to match the energy distribution and voltage coordination.
Proper installation of lightning protection devices is crucial. Multi-level protection is often necessary, especially when dealing with long cables or multiple protected devices. The placement of the arrester relative to the equipment matters, as excessive distance can reduce effectiveness. Additionally, the layout of connecting wires should minimize inductive effects and ensure that the arrester is as close as possible to the point of entry.
In some cases, improper installation can increase the risk of damage. For instance, if a single arrester is placed at the front end without any upstream protection, it may not be able to handle large surges, leading to failure. Therefore, a layered approach with multiple stages of protection is recommended, ensuring that each level works together to manage energy and voltage effectively.
Finally, the grounding of the arrester must be connected to the equipment's protective ground to avoid dangerous voltage differences during transients. All aspects of lightning protection—design, installation, and maintenance—must be considered to ensure the safety and reliability of electronic systems.
Heat Shrink Tube
Heat Shrink,Heat Shrink Sleeve,Shrink Wrap Tubing,Adhesive Lined Heat Shrink Tubing
Dongguan Zhonghe Electronics Co., Ltd. , https://www.zhonghesleeving.com