Soft starter for motor starting duty
The Siemens 3RW5213-3TC14 is a hybrid switching device — a soft starter — sized for three-phase induction motors on 200-480 V AC supplies. Its default trip class is CLASS 10A per IEC 60947-4-2, meaning it protects the motor during start-up by limiting thermal stress to the winding insulation within a 10-second overload window at locked-rotor current. The unit also accepts CLASS 10E or 20E settings if the application needs a longer acceleration ramp. Minimum settable current is 5.5 A, and the minimum load is 15 % of the smallest settable Ie, so it handles small motors down to about 1.1 kW at 400 V without dropping out.
Fieldbus and control integration
This soft starter carries onboard PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP, plus PROFINET standard and PROFIenergy support when paired with the PROFINET communication module. That means it drops directly into a Siemens S7 environment over PROFINET or into a Rockwell plant over EtherNet/IP without a gateway. The Modbus TCP interface also suits legacy SCADA retrofits where the control room speaks Modbus. Remote reset is handled by cycling the control supply voltage — no separate digital input needed for that function.
Mounting and mechanical fit
Mounting is by screw fixing onto a vertical surface, with +/-10° rotation and forward/backward tilt allowed. The enclosure dimensions are 275 mm height, 170 mm width, and 152 mm depth — that's a fairly tall unit, so verify the backpanel height before laying out the cabinet. Clearance requirements: 100 mm upwards, 75 mm downwards, 10 mm forwards, 0 mm backwards, and 5 mm at the sides. The backwards clearance of zero means it can sit flush against a backplate, which helps in shallow enclosures. Terminal capacity accepts 2x (1.0 to 2.5 mm²) and 2x (2.5 to 10 mm²) solid conductors — the larger terminals handle the main power wiring, while the smaller ones suit control circuits. Shock resistance is rated at 15 g / 11 ms, with potential contact lifting starting at 12 g / 11 ms, so it's suitable for industrial machinery but not high-vibration environments like hammer mills without additional damping.