SIRIUS S0 thermal overload relay, 25 A, CLASS 10
The Siemens 3RU7126-4DB0 is a SIRIUS S0-size thermal overload relay rated 25 A operational current, CLASS 10 trip class, for 3-phase AC/DC main circuits up to 690 V, 50/60 Hz. It mounts directly to the corresponding S0 contactor, saving DIN-rail space and reducing wiring — the fastening method is contactor mounting, with the relay sitting on top of the contactor and the main power connections passing through.
Dimensions are 45 mm wide × 97 mm high × 96 mm deep — the S0 footprint fits standard 45 mm contactor width, so it lines up with the contactor's power terminals. Side spacing to grounded parts is 6 mm minimum; the IP20 finger-safe terminals on the front and at the connection points are rated for protected environments only — no washdown, no outdoor exposure without an enclosure.