DC-rated miniature circuit breaker for 440V rail systems
The Siemens 5SY5220-6CC12 is a 2-pole miniature circuit breaker from the 5SY5 CRH series, rated for 440V DC with a 10kA breaking capacity and a B20 tripping characteristic. The B20 curve means it trips between 3 and 5 times rated current (60–100 A magnetic release), suited for resistive and light inductive DC loads where short-circuit protection is the priority, not motor inrush.
Rated for 440V DC, it is a natural fit for DC bus protection in variable-speed drive cabinets, battery-bank branch circuits, or photovoltaic combiner boxes where the string voltage reaches 440V DC.