The Siemens SIRIUS 3RB2026-1QB0 is a solid-state overload relay rated Class 10E, meaning it will trip within 10 seconds at 7.2× the set current — fast enough to protect standard induction motors during locked-rotor starts without nuisance tripping on normal acceleration. It mounts directly on a contactor (contactor mounting per), saving DIN-rail space in the panel.
ATEX and environmental fit
Carries PTB 06 ATEX 3001 Ex II (2) GD certification, so it is approved for use in potentially explosive gas and dust atmospheres — Zone 1/2 gas and Zone 21/22 dust when installed in a suitable enclosure.
Switching capacities and auxiliary contacts
The relay provides no auxiliary contacts — all switching is internal to the solid-state trip circuit. For signal feedback, you must add an external contact block. Rated switching capacities: 2 A at 24 V, 4 A at 120 V, 3 A at 230 V. The 0.02 W per pole dissipation keeps heat low in the enclosure.
EMC and surge immunity
Burst immunity tested to IEC 61000-4-4 severity 3: 2 kV on power ports, 1 kV on signal ports. Surge voltage resistance rated 6 kV. These figures mean the relay holds its trip accuracy in industrial environments with switching transients from contactors and drives — no external suppression needed for most panels.