Soft starter with hybrid switching and multi-protocol fieldbus
The 3RW5244-6AC05: It uses hybrid switching technology (product category: hybrid switching devices) to combine the low heat dissipation of a solid-state start with the low on-state losses of a bypass contactor during run. Trip class is selectable as CLASS 10A (default), 10E, or 20E per IEC 60947-4-2, giving the commissioning engineer flexibility to match the motor start profile — 10A for standard starts, 20E for higher-inertia loads where the start time extends beyond 10 seconds. Fieldbus integration covers PROFINET standard, PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP, plus PROFIenergy support when paired with the PROFINET communication module. This makes it a drop-in for most modern control architectures without a separate gateway.
Mounting, cooling, and environmental limits
Fastening is by screw fixing. The mounting position allows a vertical mounting surface rotatable ±90° and tiltable ±22.5° front-to-back, so the unit can be oriented to fit tight panel layouts while keeping the cooling airflow vertical. Clearance requirements: 100 mm upwards, 10 mm forwards, 75 mm downwards, 5 mm at the side, and 0 mm backwards. The backwards zero-clearance means the back of the unit can sit flush against the panel backplate, saving depth in shallow enclosures. Shock resistance is 15 g / 11 ms, with potential contact lifting above 12 g / 11 ms. Pollution degree 3 per IEC 60947-4-2 means the device is rated for industrial environments where conductive pollution (dust, moisture) can occur — no additional conformal coating required for typical panel conditions.
Lifecycle, approvals, and sourcing posture
Approvals include CE marking, UL approval, and CSA approval. These cover the major North American and European regulatory jurisdictions, so the part can be specified into panels destined for either market without additional certification work.
Motor control features: pump ramp, soft torque, and reset options
Pump Ramp Down is available — this is a specific deceleration profile that reduces water hammer in pump applications by extending the stop time. Soft Torque is also supported, which lowers the starting torque for gentle acceleration of conveyors or other loads sensitive to mechanical shock. The analog output can be set to 4-20 mA (default) or 0-10 V (parameterizable with the High Feature HMI). This gives the controls integrator a direct speed or current signal back to the PLC without an external transducer. Auto-reset and remote reset (by cycling the control supply voltage) are both supported, which helps in unattended restart scenarios after a fault clears — common in remote pump stations or conveyor lines. Minimum load is 15 % of the smallest settable Ie. Below that, the soft starter may not detect the motor current reliably — the field service tech should verify the motor FLA is above this threshold before commissioning.