Sourcing & lifecycle — phased out, successor identified
The 3RV1042-4FA10-ZX95 is a phased-out product from the Siemens SIRIUS 3RV1 generation. The official successor is the SIRIUS 3RV2 series, which carries the same S3 frame size and screw-terminal footprint, making a panel swap straightforward without rewiring the main power circuit.
The 28…40 A thermal overload release is Class 10 — it trips within 10 seconds at 7.2× the set current, matching the startup profile of standard AC induction motors. The 520 A fixed short-circuit release provides magnetic trip for fault currents above that threshold, protecting the downstream contactor and cable. The 23 W total power dissipation (7.7 W per pole) at hot operating state means the panel designer should account for that heat load when spacing adjacent devices, especially in a sealed enclosure.
Typical deployment is on a DIN-rail-mounted motor feeder in a control panel, protecting a pump, fan, or conveyor motor. The increased switching capacity variant handles higher fault currents than the standard S3 breaker, which matters when coordinating with upstream fuses or a molded-case breaker for selectivity.
Compliance documentation
The part carries a Substance Prohibitance date of 07/01/2006, indicating RoHS compliance for the European market from that date. As a Siemens SIRIUS product, it is designed to meet IEC 60947-2 and IEC 60947-4-1 standards for circuit breakers and motor starters; UL/CSA listings are typical for the series but should be verified against the specific variant's markings.