Abstract : This paper introduces the problems with the neon lamp in the DH-3 reclosing relay, analyzes the causes of these problems, and proposes improvement methods. Keywords: Neon lamp; LED; Reclosing relay 1 Overview Reclosing relays are the main components used in transmission lines to achieve three-phase single-phase reclosing and are widely used in power systems. The DH-3 reclosing relay is a key component in reclosing devices. The performance of the reclosing relay directly affects the performance and reliability of the reclosing device. Currently, the DH-3 reclosing relay used domestically is a replacement for the DH-2A reclosing relay and has been in operation in power systems for over twenty years. It features simple principle, reliable operation, convenient debugging, and strong anti-interference ability, making it popular with users. However, some shortcomings have been discovered during years of operation, such as: short lifespan of the signal monitoring lamp (damage occurs in about one year), insufficient capacitor charging in some relays in humid areas preventing intermediate output operation, difficulty in debugging the neon lamp, and yellowing of the neon lamp. To address these shortcomings, our company has improved the DH-3 reclosing relay, resolving these issues. The improved model is DH-3A. Its internal terminals and structure are completely identical to the DH-3, and they are directly interchangeable. 2. Problems and Causes of the DH-3 Relay [b][align=center]For details, please click: Improvement of the Neon Lamp in the DH-3 Reclosing Relay[/align][/b]