The Siemens 3SE6605-2BA is a SIRIUS magnetically operated reed switch in a rectangular plastic block housing, 25 x 13 x 88 mm, with a 3 m PVC cable and screw fixing. It is designed for safety-related circuits — Category 4 per EN 954-1 — and carries one NC and one NO reed contact rated at 400 mA / 100 V AC/DC, 10 W. The assured operating distance is 5 mm ON, 15 mm OFF, and the sensor requires a separate evaluation unit (not included).
The 5 mm assured ON distance and 15 mm OFF distance define the gap between the sensor face and the actuator magnet that guarantees the switch state — critical for guard-door interlock placement where the door seal gap must stay under 5 mm for the safety function to hold. Category 4 per EN 954-1 means the switch architecture detects a single fault without losing the safety function, and a second fault is detected before the next demand. The IP67 rating means the sensor body and cable entry withstand washdown and temporary immersion — suitable for food, beverage, or outdoor conveyor lines where hose-down cleaning is routine. The sensor cannot be flush-mounted (no flush installation possible), so plan for a 25 mm wide surface-mount footprint with clearance around the active face.
Integration notes
Screw fixing into a panel or machine frame — no DIN-rail clip on this block housing. The 3 m PVC cable terminates in flying leads; plan for a cable gland or strain relief at the panel entry. The reed contacts are dry (no positive opening mechanism), so the safety circuit must rely on the external evaluation unit for cross-circuit/short-circuit recognition, which the sensor supports. Shock resistance to 30 g / 11 ms sinusoidal half-wave and vibration resistance to 1 mm at 10–55 Hz per IEC 60068-2-27 and IEC 60068-2-6.