Summary of key points of lightning protection for switching power supplies

　　1. In order to achieve unattended operation, modern communication switching power supplies are equipped with remote monitoring functions, such as remote signaling, remote measurement, and remote control. However, the signal line interface connected to it has a long communication distance and is very susceptible to damage from induced lightning, resulting in accidents such as shutdowns. According to the requirements of the Ministry of Information Industry, corresponding signal lightning arresters should be installed for protection.

　　2. The installation of DC lightning arresters was proposed in the recently released lightning protection standards. Because the residual voltage of DC lightning arresters is much lower than that of AC lightning arresters, it can effectively improve the ability of sensitive equipment in communication switch power supply communication stations to resist lightning electromagnetic pulses.

　　3. The lightning protection capability of the lightning arrester is closely related to the installation method. Mainly, the lead inductance will produce additional residual pressure. The length of the connection between the power line and the lightning arrester and the connection between the lightning arrester and the grounding junction board should be shortened as much as possible.

　　4. Arranging lightning arresters in multiple stages can reduce the additional residual pressure caused by lead inductance, because the front-stage lightning arrester has discharged most of the lightning current into the ground, and the rear-stage lightning arrester only discharges a small part of the lightning current. The reduction of lightning current will inevitably lead to a reduction in the additional residual pressure on the lead. In order to ensure the energy coordination of the front and rear stages of the lightning arrester, the length of the power cable between the lightning arresters should be no less than 15 meters, otherwise a decoupler should be used for energy coordination.

　　5. The lightning protection of incoming power cables is easy to attract attention, while other power lines in and out of the communication station are often neglected, such as lighting street lamp lines, tower lamp power lines, and non-telecom facilities rented telecommunications power lines. Now it is advisable to use solar tower lights, which can reduce a lightning intrusion channel. Other outgoing power lines should be within the protection range of the lightning protection system, otherwise special lightning protection measures should be taken.