The NP800 Closed-loop Backup Automatic Transfer (BZT) is suitable for non-interruption power transfer switching in 400V low-voltage main/backup incoming line systems, ensuring the safe operation of power lines and equipment. Traditional backup automatic transfer switching requires disconnecting one power source circuit breaker with a time delay before closing another power source and bus-tie circuit breaker to resume power supply. This process involves a brief delay during switching, which cannot meet the requirements of systems that must not experience power interruptions. The NP800 Closed-loop Backup Automatic Transfer effectively overcomes this drawback, achieving uninterrupted and delay-free power transfer switching. Working principle: The NP800 series low-voltage backup automatic transfer device adopts a 32-bit DSP and a 5-inch touch screen, providing a user-friendly interface and convenient operation; other models under development include: NP807: Two incoming lines + generator (single busbar non-sectioned) NP805: Two incoming lines single busbar non-sectioned (with paralleling) NP803: One incoming line one tie + generator NP802: Two incoming lines one tie backup automatic transfer (single busbar sectioned) NP800: Two incoming lines one tie (auto transfer auto recovery, auto transfer manual recovery, manual, manual closed-loop, automatic closed-loop, selective trip, remote) with various time parameters to meet different application needs. The NP800 low-voltage backup automatic transfer device features an interface design that displays the primary system diagram and relevant analog and digital data in real time. Overview of the NP800 series low-voltage backup automatic transfer device (integrated type): Integrates voltage measurement/display, digital input/output, and network communication functions. It offers intuitive display, simple operation, and easy maintenance. It is mainly used in distribution systems below 690V to perform fast and reliable switching between main and backup power sources, ensuring reliable production power supply. The embedded PLC module provides multiple logic function options, allowing adjustment of various parameters according to field operation requirements. It can be installed at different locations within the distribution system and applied in low-voltage distribution systems of power systems, industrial and mining enterprises, public facilities, intelligent buildings, and railways. Remote data management is achieved through its standard RS-485 communication interface.