SIRIUS 3RU2136-4QB0 — CLASS 10 thermal overload relay, size S2
The Siemens 3RU2136-4QB0 is a SIRIUS-brand thermal overload relay, size S2, designed for contactor mounting. Rated for motor loads up to 30 kW at 400 V, 37 kW at 500 V, and 55 kW at 690 V, with a maximum current rating of 57 A at both 480 V and 600 V. The auxiliary contacts handle 2 A at 24 V and 230 V, 3 A at 120 V, 1 A at 400 V, and 0.75 A at 690 V — enough for signaling back to a PLC or contactor coil.
Integration — contactor-mount, size S2, any position
Mounts directly onto the matching SIRIUS contactor (size S2) without additional hardware — no DIN rail required, though it can be panel-mounted if needed. Fastening method is contactor mounting; the relay snaps onto the contactor's frame and connects electrically through the power terminals. Acceptable in any mounting position. Screw terminals on the main circuit accept 2× (0.5 to 1.5 mm²) or 2× (0.75 to 2.5 mm²) solid or stranded wire. A Pozidriv PZ2 screwdriver tip (shaft diameter 5–6 mm) is specified for termination. Dimensions: 90 mm high, 55 mm wide, 105 mm deep — fits standard S2 panel cutouts. The integrated auxiliary switch provides the trip-signal output (the "for message 'Tripped'" note on the label).
Temperature compensation is active over -40 to +60 °C, ensuring the trip curve stays accurate across the operating range.