SIRIUS 3RU1126-1CB0-ZX95 — thermal overload relay, Size S0, Class 10
The Siemens 3RU1126-1CB0-ZX95 is a SIRIUS thermal overload relay in the Size S0 frame, designed for three-phase motor protection. It provides Class 10 trip characteristics, meaning it will trip within 10 seconds at 7.2× the set current — the standard for protecting standard induction motors during start-up. The relay mounts directly to a contactor via the fastening method, eliminating separate panel wiring for the power circuit.
Mounting and integration
Mounts directly onto a contactor — no separate DIN-rail footprint needed for the power loop. The mounting position allows the vertical mounting surface to be rotated ±135° or tilted ±45° front/back, giving panel layout flexibility. Clearance requirements: 0 mm upwards, forwards, backwards, and downwards; 6 mm at the side. Dimensions are 45 mm wide × 97 mm high × 96 mm deep. Screw-type terminals on both main and auxiliary circuits; accepts 2× (0.5…1.5 mm²) or 2× (0.75…2.5 mm²) solid or finely stranded with ferrule, and 2× (16…12) or 2× (14…8) AWG on the mains. Auxiliary contacts similarly rated.
Environmental and approvals
Rated for operation from -20 to +70 °C, storage and transport from -55 to +80 °C. Withstands 100 % relative humidity during operation. Shock resistance rated at 8g for 10 ms. Surge voltage resistance rated at 6 kV. Protection class IP20 on the front — suitable for enclosed panels where no water ingress is expected. Carries ATEX approval DMT 98 ATEX G 001, allowing use in potentially explosive gas atmospheres. The IEC 81346-2 reference code is F. Substance prohibition date per RoHS is July 1, 2006.
Auxiliary contact ratings and power dissipation
Auxiliary contact ratings: 1 A at 24 V, 0.22 A at 110 V, 3 A at 120 V, 0.22 A at 125 V, 0.11 A at 220 V, 2 A at 230 V, 1 A at 400 V. Power dissipation per pole is 1.9 W — three poles total 5.7 W, which must be considered in enclosure thermal calculations.