The Siemens SIRIUS 3RB2026-1RB0 is a solid-state overload relay for three-phase motor protection, rated Trip Class 10E, with one normally-closed auxiliary contact and screw-type terminals for both main and control circuits. It mounts directly onto a contactor (contactor mounting), saving panel space and simplifying wiring — no separate base or bracket needed. The ATEX approval (PTB 06 ATEX 3001 Ex II (2) GD) allows installation in Zone 2 gas and Zone 22 dust hazardous areas when paired with an appropriate contactor and enclosure.
The auxiliary circuit carries 2 A at 24 V DC and 4 A at 120 V AC, sufficient for direct PLC input or contactor coil feedback; at 230 V AC it drops to 3 A, so verify the load on a 230 V control transformer. Surge voltage withstand of 6 kV (rated impulse) and burst immunity of 2 kV on power ports per IEC 61000-4-4, severity level 3, means it will hold up in industrial environments with switching transients from contactors and drives.
Mounts in any position (any mounting position) on the contactor, with zero clearance needed upwards, downwards, forwards, and backwards — only 6 mm side clearance required. Screw terminals accept 0.5–4 mm² solid or 0.5–2.5 mm² finely stranded with ferrules, and 2× 0.5–2.5 mm² for auxiliary contacts — covers standard panel wire sizes without special tools. Shock rated 15 g / 11 ms, so it survives transport and machine vibration on a conveyor or press line.
Substance prohibitance date of 07/01/2006 indicates RoHS compliance (EU RoHS effective July 2006); the relay also carries ATEX certification and is built to IEC 60947-4-1 for overload relays.
Operating temperature range -25 to +60 °C, storage -40 to +80 °C, and 100 % relative humidity — suitable for unconditioned enclosures in washdown or outdoor environments as long as the contactor and enclosure meet the same rating.