SIRIUS 3RW52 — what this soft starter covers
The Siemens 3RW5216-3AC04 is a SIRIUS hybrid soft starter sized for three-phase motors from 200 to 480 VAC, with a minimum setting current of 14 A — that's the floor for the motor FLA you can program into it. It ships with a default trip class of CLASS 10A per IEC 60947-4-2, meaning it protects the motor during start-up by limiting the thermal stress to within 10 seconds of locked-rotor current at the set overload. You can also select CLASS 10E or 20E if the application needs a longer acceleration window.
Fieldbus fit and control integration
The 3RW5216-3AC04 carries onboard PROFIBUS, Modbus RTU, Modbus TCP, EtherNet/IP, and PROFINET — you don't need a separate communication module for any of these. It also supports PROFIenergy in conjunction with the PROFINET standard communication module. The analog output is configurable as 4-20 mA (default) or 0-10 V via the High Feature HMI, giving the PLC a real-time current or voltage signal for monitoring motor load or ramp status. Remote reset is handled by cycling the 24 VDC control supply off and back on — no need to walk to the panel for a manual reset after a fault trip.
Mounting, cooling, and environmental limits
Mounting is screw-fix to a vertical surface; the unit can be rotated ±90° or tilted ±22.5° front-to-back, which helps when fitting into tight enclosures or existing backpanels. Dimensions are 275 mm high, 170 mm wide, 152 mm deep — the depth is the key number for enclosure depth clearance. Clearance requirements: 100 mm above, 75 mm below, 10 mm forward, 5 mm at the sides, and zero behind. Shock resistance is 15 g / 11 ms, dropping to 12 g / 11 ms if potential contact lifting is a concern.
Pump and process-specific features
Pump Ramp Down and Soft Torque are built in — these are the two features that matter for centrifugal pumps: the ramp-down prevents water hammer on stop, and soft torque reduces the initial current surge on start. The minimum load setting is 15 % of the smallest settable Ie, which means it can handle lightly loaded motors without nuisance tripping on the underload curve. Auto-reset is supported, and an error logbook is available but only with special accessories — not standard out of the box.
Approvals and compliance documentation
CE marked for the European market, UL and CSA approved for North American installations — the nameplate carries all three marks, so it passes inspection for panels shipping to either region. Firmware updates are field-loadable, which means you can apply later revisions without swapping the unit.