DZ931 series Moulded case circuit breaker have rotary double contacts, electromagnetic blowing and energy press trip structure which can make the MCCB with high short-circuit breaking capacity, small volume and zero arc distance. DZ931 series Moulded case circuit breaker can measure lots of parameters of power grid with the electronic trip unit combines advanced current sensors. DZ931 series Moulded case circuit breaker can be remote adjusted, communicated, measured and controlled which required by the intelligent power grid. The breakers can measure the parameters of power line and health status of itself and transfer these data to data-center. The breaks can be adjusted and controlled with communication with long distance.