The CDM3LT series transparent residual current protection moulded case circuit breaker is a new generation protection device designed for low-voltage AC distribution systems. It is suitable for AC400/415V circuits with a rated frequency of 50Hz and provides reliable power distribution and comprehensive protection for electrical lines and equipment. The circuit breaker adopts a transparent housing design, allowing users to directly observe the internal contact status of the breaker. This improves operation inspection efficiency and simplifies maintenance and troubleshooting in the field. The CDM3LT series includes CDM3LT-125 and CDM3LT-250 frame sizes, covering rated currents from 16A to 250A. The products adopt 4-pole (A/B) configurations and are suitable for three-phase four-wire low-voltage distribution systems. The series integrates residual current protection functions and supports adjustable residual operating current settings, including 30mA, 100mA, 300mA and 500mA. Both instantaneous and time-delay protection modes are available. By detecting leakage current and disconnecting the faulty circuit, the breaker effectively reduces the risk of electric shock and electrical fires. In addition to leakage protection, the CDM3LT series provides overload and short-circuit protection to protect electrical circuits and equipment from abnormal current conditions. The circuit breaker supports fixed installation and can be equipped with various accessories, including auxiliary contacts, alarm contacts, shunt trip releases and undervoltage releases. It is suitable for industrial distribution panels, commercial building electrical systems, residential applications and temporary construction power systems. The CDM3LT series complies with relevant low-voltage switchgear standards and has obtained CCC certification.