The Siemens 3RT5055-6AD36 is a SIRIUS Size S6 power contactor rated 55 kW at 690 V in AC-3e duty (switching motor loads up to that power). At 400 V and 60 °C ambient it delivers 105 kW; at 230 V and 60 °C it delivers 60 kW, which means the thermal derating is already factored into the catalog ratings — no need to recalculate for a 60 °C cabinet.
Size S6 frame: 170 mm deep × 120 mm wide × 172 mm high. Mounting is by screw fixing onto a vertical surface; the contactor can be rotated ±90° or tilted ±22.5° front-to-back, which gives flexibility in tight enclosures. Side-by-side mounting is allowed — no mandatory spacing gap, so you can pack multiple units on a DIN-mounting plate without wasting panel width.
The substance prohibition date of 03/01/2017 aligns with RoHS/REACH compliance timelines — the part is compliant with current EU substance restrictions.