The Siemens 3RW5527-1HA14 is a SIRIUS 3RW55 soft starter rated for 200-480 V supply, designed to ramp induction motors up and down smoothly, reducing mechanical shock and inrush current on conveyors, pumps, fans, and compressors. It carries ATEX and IECEx certification, so it's approved for use in potentially explosive atmospheres — a key differentiator from standard soft starters that lack hazardous-area listing. Trip Class is configurable: CLASS 10A (default), 10E, 20E, or 30E per IEC 60947-4-2. That means you can match the overload protection curve to the motor's thermal capacity — CLASS 10A for standard starts, CLASS 20E or 30E for high-inertia loads that need longer acceleration without nuisance tripping. Communication options cover PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP, plus PROFIenergy support with PROFINET modules. This makes it straightforward to integrate into existing PLC networks — no separate gateway needed for most common fieldbuses.
Approvals and compliance documentation
The 3RW5527-1HA14 carries CE marking, UL approval, and CSA approval. ATEX and IECEx certifications are listed directly on the device.
Dimensions: 306 mm height, 185 mm width, 203 mm depth. Clearance requirements: 100 mm upwards, 75 mm downwards, 10 mm forwards, 0 mm backwards, 5 mm at the sides. Screw terminals for power and control wiring. Mounts on a panel or DIN rail — the clearance numbers matter for enclosure sizing, especially the 100 mm above for heat dissipation.
Built-in control and protection features
Includes DC braking, voltage ramp, pump ramp down, torque control, breakaway pulse, motor heating, and a 4-20 mA / 0-10 V analog output. Accuracy Class 5 per IEC 61557-12. Service factor 1.15. Auto-reset and remote reset are supported. An event list, error logbook, trace function, and firmware update capability are built in — useful for commissioning and diagnostics without extra software.