Soft starter for motor control in hazardous areas
The Siemens 3RW5536-2HF14 is a SIRIUS soft starter rated for 200 to 480 V supply voltage, designed to ramp induction motors up to speed and protect them during start. Its ATEX and IECEx certification means it is approved for installation in explosive atmospheres — a key differentiator for oil/gas, chemical, or grain-handling lines where a standard soft starter would not pass site safety audit. The unit supports multiple trip classes per IEC 60947-4-2: CLASS 10A, 10E (default), 20E, and 30E, so you can match the thermal curve to the load — fast trip for submersible pumps, longer ramp for high-inertia conveyors.
Fieldbus and control flexibility
This soft starter ships with PROFIBUS onboard, plus Modbus RTU, Modbus TCP, and EtherNet/IP — covering the three common industrial Ethernet protocols without an extra option card. A 4-20 mA or 0-10 V analog output feeds motor current or load data back to the PLC for trending or alarming — useful when you are commissioning a line and want to see the start profile on the HMI without a clamp meter.
Protection and diagnostics for field service
Motor heating model, torque control, and a breakaway pulse help start a stuck load. The event list and error logbook store fault history. Accuracy Class 5 per IEC 61557-12 means current measurement within 5% of reading. B10d value of 500,000 gives mechanical endurance for high-cycle applications.
Footprint: 185 mm wide, 306 mm tall, 203 mm deep. Clearance requirements are tight: 100 mm upwards, 75 mm downwards, 10 mm forwards, 5 mm at the side, and 0 mm backwards — meaning it can sit flush against a back panel, saving enclosure depth. No screw terminals; the unit uses spring-cage or ring-lug connections typical of the SIRIUS 3RW55 frame. Panel builders should plan for the 100 mm top clearance for cable bending radius and heat dissipation.
This 3RW5536-2HF14 is an active catalog item in the Siemens SIRIUS portfolio. No lifecycle-end notice or successor has been issued.