The Siemens 3RV2021-4DA15-ZW96 is a SIRIUS motor protection circuit breaker designed for motor protection. It mounts on a 35 mm DIN rail per DIN EN 60715 using screw and snap-on fastening, with a width of 45 mm, depth of 97 mm, and height of 97 mm. The mounting position is any orientation, and it requires 50 mm clearance upwards and downwards, 30 mm at the sides, and zero forwards and backwards.
Trip Class and Breaking Capacity
Trip class CLASS 10 means the breaker will trip within 10 seconds at a locked-rotor current of 7.2× the thermal setting — standard for protecting standard squirrel-cage induction motors during start-up. The high short-circuit breaking capacities are: 100 kA at 240 V, 25 kA at 400 V, 5 kA at 500 V, and 2 kA at 690 V. These ratings ensure the breaker can safely interrupt a fault without upstream devices needing to coordinate, which simplifies panel design.
Motor Protection Features
Phase failure detection is built in, so the breaker will trip if one phase drops out during running — critical for preventing single-phasing damage to motor windings. Ground fault detection is not included; that would require a separate ground-fault module or relay. The rated operating voltage range is 20 to 690 V.