The Siemens SIRIUS 3SE3902-4CB20 is a momentary-contact foot switch in a molded-plastic enclosure rated IP65, with one pedal and a single change-over contact. It carries a 5 A AC-15 rating at 230 V, so it handles typical control-circuit loads like contactor coils and pilot lights without derating at that voltage.
The AC-15 rating of 5 A at 230 V is the key selection number — it tells you the switch can make and break inductive control-circuit loads (solenoids, contactors) at that current. The IP65 enclosure means it's dust-tight and protected against water jets, so it's suited for washdown areas or outdoor panels. Operating temperature spans -10 to +75 °C, covering most factory-floor environments. The 3 m cable entry is fixed — no terminal block inside, so you land the cable directly. Screw fixing to the floor or panel is the intended mount; no DIN-rail clip.
Dimensions & Mechanical
Footprint is 71 mm wide by 96 mm tall, with a depth of 27 mm. No latching or interlock — it's a momentary pedal, press to make, release to break. Plastic enclosure with total insulation, so no additional grounding of the housing is required.