Motor Protection Circuit Breaker, Size S3 — Phased-Out, Successor Known
Its thermal overload release is adjustable from 28 to 40 A (Class 10 trip class), and the magnetic short-circuit release trips at 520 A. It uses screw terminals and is rated for increased switching capacity. The unit is packaged in a multi-unit pack of 7 and is identified as a phased-out product. The official successor is the SIRIUS 3RV2 series.
If your BOM is still locked to the 3RV1042 prefix, this is the last production run window; the 3RV2 successor should be validated for any new builds or panel revisions.
Power Loss & Thermal Management
Total power loss in hot operating state is 23 W, with 7.7 W per pole. That heat must be dissipated into the panel ambient.
Panel Integration & Mounting
The increased switching capacity variant handles higher fault currents than the base S3 breaker, so verify the SCCR at the panel point-of-connection matches your available fault current.