The Siemens 3RB3113-4RE0 is a SIRIUS solid-state overload relay in size S00, designed to protect motor circuits by monitoring current and tripping on overload. Its adjustable trip class — selectable between CLASS 5E, 10E, 20E and 30E — lets you match the relay's thermal response to the motor's starting profile: a 5E setting trips fast for short-start loads like pumps, while 30E gives the headroom a high-inertia fan or conveyor needs without nuisance trips. The trip threshold itself is set by the motor's full-load current, with the relay tripping when IMotor exceeds the upper current setting value by up to 3.5 times, and resetting once IMotor drops below the lower current setting value. The relay mounts directly onto a contactor (fastening method: contactor mounting), saving DIN-rail space in the panel. Its 45 mm width and 90 mm depth fit the S00 footprint common in Siemens SIRIUS motor starter assemblies. Spring-loaded terminals on the main current circuit accept 2x (0.25 to 1.5 mm²) solid or stranded wire — no screw tightening needed, which speeds wiring on a build line. The auxiliary signaling contact is rated for switching at multiple control voltages: 2 A at 24 V, 4 A at 120 V, 3 A at 230 V, and 0.4 A at 480/600 V. That covers most PLC input and contactor coil circuits across global control voltages. The contact's note specifies it is for message 'tripped' — meaning it changes state only when the relay has operated, not on power loss or manual test. Thermal dissipation per pole is just 0.03 W, so heat buildup in a densely packed panel is negligible.
Mounting and integration into a panel
Mounting position is any orientation, so the relay fits upright, sideways, or inverted inside a crowded enclosure without derating. Vibration resistance is specified at 1–6 Hz, 15 mm amplitude and 6–500 Hz, 20 m/s² over 10 cycles — suitable for mounting on a machine frame or in a mobile equipment panel. Shock resistance is 15g for 11 ms. Wiring to the spring-loaded terminals needs a Pozidriv PZ2 screwdriver with a shaft diameter of 5 to 6 mm for the main contact screws (M3). The signaling contact wiring uses the same 2x 0.25–1.5 mm² solid or stranded wire as the main circuit. No special tools beyond the screwdriver and a wire stripper set to 8–10 mm strip length.
RoHS compliance is documented with a substance prohibition date of 10/01/2009, covering the EU RoHS directive. The part carries the SIRIUS brand name and is designed to IEC standards for overload protection.