Trip class and motor protection profile
The 3RW5235-2AC05 ships with a default trip class of CLASS 10A per IEC 60947-4-2, with selectable CLASS 10E and CLASS 20E profiles. For a pump or conveyor with a normal starting duty cycle, 10A is the baseline — it clears the start within 10 seconds at 600% locked-rotor current. If you're starting a high-inertia load like a centrifuge or a large fan, bump it to 20E so the soft starter doesn't nuisance-trip during the acceleration ramp. The minimum load setting is 15% relative to the smallest settable Ie — meaning if you're running a motor that draws well below the 68 A minimum, the soft starter may not regulate properly. Keep the motor FLA at or above 68 A to stay in the control band.
Fieldbus and control integration
This SIRIUS soft starter carries onboard PROFIBUS, Modbus RTU, Modbus TCP, EtherNet/IP, and PROFINET — all five protocols are available without an add-on module. If your plant runs a mixed-protocol environment, you can commission the same unit across different network segments by swapping the parameter set. The analog output is configurable as 4-20 mA (default) or 0-10 V via the High Feature HMI parameter set. This gives the PLC a live current signal for trending motor load without a separate transducer. PROFIenergy is supported when used with the PROFINET communication module — useful for shutting down non-critical loads during idle periods in automotive or machining lines.
Mounting, clearances, and thermal derating
The unit measures 306 mm high, 185 mm wide, and 203 mm deep — screw-fixing mount, not DIN rail. You need 100 mm clearance above, 75 mm below, 10 mm forward, and 5 mm on each side. Zero clearance required at the rear, so you can push it against the back panel. If the panel ambient hits 50 °C, expect the continuous current rating to drop — plan your wire sizing and thermal management accordingly. Mounting position is flexible: vertical surface with ±90° rotation, and ±22.5° tilt forward/back. That helps when the sub-panel is angled inside the enclosure.
Soft torque, pump ramp, and reset logic
Soft Torque is enabled — this reduces the initial current spike on high-friction loads like conveyors with stuck rollers. Pump Ramp Down gives a controlled deceleration profile for centrifugal pumps, preventing water hammer on the discharge line. Auto-reset is standard, and a remote reset is available by cycling the 24 V control supply. If the starter trips on a fault, the PLC can toggle the control voltage to clear the trip without a site visit. Shock resistance is rated at 15 g / 11 ms, with potential contact lifting above 12 g / 11 ms — fine for most industrial panels, but if the machine sees repetitive hammering (stamping presses, rock crushers), consider adding vibration dampers.
Compliance and documentation
The 3RW5235-2AC05 carries CE marking, UL approval, and CSA approval — covering the three major regulatory jurisdictions for industrial control panels. Firmware updates are supported, and an error logbook is available with special accessories — useful for tracking repeated fault conditions on a critical motor.
Sourcing and lifecycle status
For a panel originally specified around a different soft starter (e.g., 6ED1052-1MD08-0BA1 or 6ES7517-3FP00-0AB0), this unit will not drop in without rewiring — the footprint, mounting, and control wiring differ. A panel re-spin is required.