Application of auto-reclosing residual current device in lightning protection for communications power supply

Lightning strike can cause the disconnection of residual current device (RCD) for communications power supply, leading to power supply disconnection and communication interruption. Auto-reclosing RCD can automatically reclose after disconnection and thus power supply is restored. Clearly, auto-reclosing RCD can help improve the ability of communication system resisting lightning strike. In addition, it solves the problem that without a supervisor, equipment cannot resume working in time after lightning strike. In this paper, the reason that lightning strike caused disconnection of RCD is analyzed. Then, we illustrate the working principle, performance requirements and safety problems of auto-reclosing RCD, and finally specific numerical requirements for auto-reclosing RCD are given.