Siemens 3RU1146-4DB0 — SIRIUS Thermal Overload Relay, CLASS 10, S3 Frame
The Siemens 3RU1146-4DB0 is a SIRIUS thermal overload relay, size S3, with CLASS 10 trip characteristic. Mounting is via contactor mounting — the relay fastens directly to the matching SIRIUS contactor, eliminating separate DIN-rail space. The mounting position allows a vertical mounting surface with ±135° rotatability and ±45° tilt to front and back, giving panel layout flexibility. Front protection is IP20, meaning finger-safe against accidental contact but not sealed against moisture. The enclosure carries ATEX certification (DMT 98 ATEX G 001), permitting installation in potentially explosive gas atmospheres when used with the correct upstream protection.
For short-circuit coordination, with type of coordination 2 required, the maximum upstream fuse is gG 63 A. With type of coordination 1 required, the maximum is gG 160 A. This defines the selectivity boundary for the protection scheme — coordination 2 preserves the relay's serviceability after a fault, coordination 1 allows the relay to be damaged but the installation remains safe. Auxiliary contact ratings are provided for multiple control voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. These are the make/break capacities for the built-in auxiliary contacts used in the control circuit.
Environmental and Mechanical Specifications
Relative humidity during operation can reach 100 %, so the relay is suitable for condensing environments without additional conformal coating. Shock resistance is 8 g for 10 ms, meeting typical industrial vibration profiles for contactor-mounted relays in motor control centers. Dimensions: 120 mm height, 70 mm width, 140 mm depth. The 140 mm depth is the dimension behind the panel face — verify clearance in the enclosure depth before specifying. Main circuit terminals accept stranded conductors: 2x (10 to 50 mm²) or single 10 to 70 mm². Auxiliary and control circuit terminals accept solid conductors: 2x (0.5 to 1.5 mm²) and 2x (0.75 to 2.5 mm²). AWG equivalents for main contacts: 2x (10 to 1/0) or 1x (10 to 2/0).
Substance prohibitance date is 07/01/2006, aligning with the original EU RoHS directive effective date. The relay is RoHS-compliant per that baseline.