What it is and where it lands
The Siemens SIRIUS 3RT1336-3XF40-0LA2 is a size S2 power contactor designed for switching motor loads and resistive circuits in industrial control panels. It carries an 11 kW rating at AC-2 duty on 400 V, which means it handles slip-ring motor starting and reversing loads up to that power level — the AC-2 category covers wound-rotor motors where the inrush is moderate but the switching frequency can be higher than a standard AC-3 contactor. The 110 VDC coil includes a built-in varistor surge suppressor, so you don't need an external RC snubber for coil suppression on DC control circuits.
Mounting and panel integration
Fastens via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022. Side-by-side mounting is supported, so multiple contactors pack tightly in a row without derating. Clearance around the enclosure: 10 mm upwards, 10 mm forwards, 10 mm downwards, 10 mm at the side. Overall dimensions: 142 mm high, 73 mm wide, 130 mm deep — the S2 frame fits standard 200 mm deep enclosures with headroom for wiring ducts.
Termination and wiring
Main current circuit uses screw-type terminals accepting 2x (0.75 … 16 mm²) solid or stranded, or AWG 2x (18 … 2). The auxiliary and control circuit uses spring-loaded terminals — no screw tightening needed for the signal wiring, which speeds up panel assembly. Solid wire range for auxiliaries: 2x (0.25 … 2.5 mm²); stranded: 2x (0.75 … 25 mm²). The dual-conductor capacity on each terminal is useful when daisy-chaining control power through multiple contactors.
Auxiliary contact switching capacity
The built-in auxiliary contacts (instantaneous, 0 delayed) handle: 10 A at 24 VDC, 2 A at 60 VDC, 1 A at 110 VDC, 0.3 A at 220 VDC, 6 A at 230 VAC, 3 A at 400 VAC. These are the make/break ratings for the contact block — stay within these curves for reliable DC switching, especially at the higher voltages where arc extinction is harder. The arcing time runs 10 … 15 ms; the DC break time is 15 … 30 ms depending on the circuit time constant.
Environmental and compliance
Operating temperature range: -40 … +70 °C; storage range: -55 … +80 °C. The substance prohibition date of 05/01/2012 aligns with RoHS compliance for the European directive. The varistor design of the surge suppressor means the coil suppression is built in — no separate suppressor module to order.