Trip Class 10A default — what that means for motor starts
The Siemens 3RW5245-6AC04 SIRIUS soft starter ships with Trip Class 10A as its default setting, per IEC 60947-4-2. That means it allows the motor to draw starting current for up to 10 seconds before the overload protection trips — the standard choice for centrifugal pumps, fans, and light conveyors where the load accelerates quickly. The unit can also be configured to Class 10E or 20E via the integrated HMI or fieldbus, giving you the headroom for high-inertia loads like crushers or long belt conveyors that need more ramp time. The 135 A floor means it's sized for motors in the 55-75 kW range depending on duty cycle — not a fractional-horsepower unit, but a serious piece of gear for a pump house or conveyor drive.
Fieldbus options — PROFIBUS, Modbus, EtherNet/IP, PROFINET
This soft starter comes equipped for PROFIBUS, Modbus RTU, Modbus TCP, EtherNet/IP, and PROFINET communication out of the box. That's unusual breadth for a single order code — most starters force you to buy a separate communication module. Here, the fieldbus interface is integrated, so you can drop it onto a PROFINET ring or a Modbus RTU multidrop without extra hardware. The analog output is configurable as 4-20 mA or 0-10 V, giving the PLC a direct speed or current feedback signal. PROFIenergy is supported when used with the PROFINET communication module, allowing coordinated energy-saving pauses during non-production periods. The unit also logs errors to an internal logbook when the special accessory is fitted — useful for root-cause analysis on a line that trips intermittently.
Mounting and environment — screw-fixed, derate above 40 °C
Mounting is by screw fixing onto a vertical surface, with the unit rotatable ±90° and tiltable ±22.5° front-to-back. Clearance requirements: 100 mm above, 75 mm below, 10 mm forward, 5 mm sideways, 0 mm backward. That 100 mm upward gap is non-negotiable for airflow — pack it tighter and you'll cook the thyristors. In a non-air-conditioned panel in a hot plant, you'll need to reduce the rated current or add forced ventilation. Shock resistance is rated at 15 g / 11 ms, dropping to 12 g / 11 ms if there's risk of contact lifting.
The 3RW5245-6AC04 is listed as current production (active lifecycle stage). No end-of-life notice, no successor order code to track.