The 3RK4320-3BQ51-0BA3: It integrates motor protection, switching, and bus communication into a single unit, eliminating the need for separate contactor, overload relay, and gateway in many distributed motor control applications. Rated 0.8 A at AC-3 at 400 V, this starter is sized for small motors — fractional-horsepower pumps, fans, or conveyor drives — where the full-load current stays under that threshold. The Class 10 trip characteristic means it disconnects within 10 seconds at 600% of the set current, protecting the motor from locked-rotor events without nuisance tripping on normal starts. The unit includes a motor brake output (400 V AC) and two digital inputs, so it can handle basic local control and brake commands directly, reducing wiring back to a central panel.
Panel fit and mounting flexibility
Dimensions are 205 mm deep, 245 mm wide, and 215 mm high — a compact footprint for a combined starter-and-bus node. The enclosure is rated IP54, meaning it's protected against dust ingress and splashing water, suitable for installation in industrial environments where washdown or airborne particulates are a concern. Mounting is flexible: the unit can be rotated ±180° on a vertical surface and tilted forward or backward by ±22.5°, allowing it to fit into tight or awkward panel layouts without forcing a rework of the backplate.
Power supply and operating conditions
Short-circuit protection is provided by circuit breakers (integrated or upstream), and the unit is designed for a maximum operating frequency of 80 cycles per hour — sufficient for intermittent-duty applications like indexing conveyors or batch mixers.