The Siemens SIRIUS 3RB3046-2XB0 is a solid-state overload relay, S3 size, rated for CLASS 20E trip curve and a thermal current of 115 A. It mounts directly onto a contactor via the screw-type main terminals — no separate panel bracket needed, which saves DIN rail space in a crowded enclosure. The integrated auxiliary switch reports a "tripped" status signal, so the PLC or HMI knows exactly when the relay has locked out.
CLASS 20E means the relay allows up to 20 seconds of overload before tripping at 7.2× the current setting — that's the standard for medium-starting loads like compressors or conveyors. The 115 A thermal current (at 480 V and 600 V) sets the upper bound for the motor full-load current you can protect; size the relay so the motor FLA falls within the adjustable range of the 3RB30 family. The auxiliary contact ratings cover common control voltages: 2 A at 24 V DC, 4 A at 120 V AC, 3 A at 230 V AC — enough to drive a PLC input or a small contactor coil directly.
Fastening method is contactor mounting — the relay bolts onto the contactor's main terminals using M6 screws (screwdriver tip Pozidriv PZ2). Main circuit wiring accepts solid or stranded up to 2× 16 mm² per pole. The auxiliary switch is integrated, so there's no separate add-on block to order. Dimensions: 70 mm wide, 106 mm high, 124 mm deep — fits standard S3 contactor footprints.