S0 direct starter with safety-rated overload
The Siemens 3RA7142-1DA26-0AB4 is a SIRIUS direct starter load feeder in the S0 frame, combining a contactor and thermal overload relay in one package for motor starting and protection up to 1.1 kW at 400 V AC-3. Rated operating current is 2.7 A at 400 V AC-3, with an adjustable overload release covering 2.2 to 3.2 A — set it to match the motor FLA before commissioning. Safety-integrity rating is SIL 3 per IEC 61508 and Category 4 per EN 954-1, meaning the internal monitoring and redundant structure meet the highest standard for guarding circuits — suitable for hazard zones where a single fault must not cause loss of the safety function.
IP20 finger-safe protection; install inside an enclosure rated for the ambient conditions.
Fault clearing and coordination
Short-circuit protection is built in; the unit is designed for cascading (Type 2 coordination) so downstream devices are protected under fault.