Soft starter for motor starting in hazardous areas
The Siemens 3RW5076-2TB14 is a soft starter rated for 200-480 V with a minimum setting of 200 A, designed to ramp motors up and down smoothly while limiting inrush current. It carries ATEX, UKEX, and IECEx approvals, meaning it can be installed in explosive atmospheres where a standard starter would be a fire risk — the enclosure and internal arcing protection meet the zone requirements. Trip class is configurable between CLASS 10A, 10E (preset), and 20E per IEC 60947-4-2, so you match the overload protection to the motor's thermal capacity — 10A for standard motors, 20E for high-inertia loads like centrifuges.
Fieldbus integration and starting profiles
Supports PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP — the soft starter talks directly to the PLC without a separate gateway, saving a slot in the control cabinet. Starting profiles include soft torque, voltage ramp, and pump ramp down — the pump ramp down feature prevents water hammer on discharge lines by extending the deceleration time. Auto-reset and remote reset (by cycling the control supply voltage) let the starter recover from a fault without a site visit, which matters for remote pumping stations or conveyor lines.
Mounting and environmental limits
Mounts via screw fixing — no DIN-rail clip, so plan for a backplate or panel with drilled holes. Dimensions are 282 mm deep, 160 mm wide, 230 mm high; allow 100 mm clearance above and 75 mm below for airflow. Shock resistance is 15 g / 11 ms — it survives the bump of a nearby press or crusher without the contacts lifting.
CE marked for the European market, UL and CSA approved for North America — the documentation package covers RoHS and REACH compliance as standard for Siemens industrial controls.