The YCQ9Ms series dual-power automatic transfer switch (ATS), model 4P / 100A, is designed for AC power systems at 50/60 Hz with a rated operating voltage of 400V. It enables automatic switching between two power sources (main and standby), ensuring continuity of power supply in case of voltage anomalies (overvoltage, undervoltage, or phase loss). The unit includes built-in RS485 communication using MODBUS-RTU protocol, for real-time data upload, remote monitoring, configuration, and control. It is ideal for critical applications like hospitals, commercial centers, hotels, high-rise buildings, fire protection systems etc. Operating temperature range -5°C to +40°C, and installation altitude no more than 2000 m.