The ZKM3 series plastic shell circuit breaker (hereinafter referred to as the circuit breaker) has a rated insulation voltage of 800V and is suitable for infrequent switching and motor starting in circuits with AC 50Hz, rated working voltage of 690V and below, and rated working current up to 800A (ZKM3-800 without motor protection type). Circuit breakers can have overload alarm without tripping function. Circuit breakers equipped with this function only output overload signals without tripping, ensuring power supply continuity. Circuit breakers have overload, short circuit, and undervoltage protection functions, which can protect lines and power equipment from damage. Circuit breakers also have isolation functions. Circuit breakers can be installed vertically or horizontally. It has the characteristics of small size, high breaking height, short arcing (some specifications have zero arcing), and anti vibration.