The Siemens 3RU7136-4HB0 is a SIRIUS Size S2 thermal overload relay rated for 50 A operational current with a CLASS 10 trip characteristic. It mounts directly to a Size S2 contactor and protects three-phase AC/DC motor circuits up to 690 V, 50–60 Hz. Front face carries IP20 protection; the screw terminals are IP00, so plan enclosure sealing accordingly.
Dimensions and panel fit
Body footprint is 118 mm deep by 55 mm wide by 105 mm tall. Side clearance to grounded parts needs 6 mm minimum. Mounting position allows ±135° rotation on a vertical surface and ±45° tilt front/back — useful when the gland plate forces an angled contactor row.
Termination and wiring
Main and auxiliary/control circuits use screw-type terminals. Main terminals accept 2× (0.5–1.5 mm²) solid/stranded or 2× (0.75–2.5 mm²) with ferrule, torqued to 3–4.5 N·m.
Environmental and compliance
Operational temperature range is -20 to +55 °C, with 0–90 % relative humidity. Storage/transport range extends to -25 to +70 °C. Installation altitude is limited to 2 000 m above sea level. Surge voltage resistance is rated at 6 kV. The lifecycle stage is marked current — this is a production-active Siemens catalog item, not a phase-out line.