The Siemens SIRIUS 3SF1324-1SF21-1BA4 is a mechanical safety switch with a separate actuator and tumbler, designed for guard door monitoring in safety circuits. Its spring-actuated lock operates on the closed-circuit principle, meaning the lock engages when power is removed — fail-safe for a guarded zone. The 1300 N locking force holds the guard closed against forced entry, meeting the 1000 N minimum per EN ISO 14119 for personnel protection.
IP65/IP67 means the housing withstands hose-down and temporary immersion — suitable for washdown zones in food processing or outdoor conveyor gantries. The M12 fixed plug carries ASIsafe on pins 1 and 3, with the magnet coil supplied at 24 V. Channel 1 monitors the actuator (2 NC contacts); channel 2 monitors the magnet (1 NC). Both channels follow a 2v2 evaluation principle, which means the safety PLC sees two independent signal paths per guard — no single fault goes undetected.
Mechanical endurance and environmental range
Rated for 1 000 000 switching cycles typical, with repeat accuracy of 0.1 mm — consistent detection over the life of the machine. Shock resistance at 30g / 11 ms and vibration resistance at 0.35 mm / 5g per IEC 60068-2-27 and IEC 60068-2-6, respectively.
Mounting and actuation
Screw fixing, any mounting position. The actuator accepts approach from 5 directions, with a minimum actuating force of 30 N. The housing is plastic with a special design; the switch head is also plastic. Positive opening of the NC contacts is confirmed — a mechanical guarantee that the contacts break even if welded, required for safety functions per IEC 60947-5-1. The matching separate actuator (3SE5000-0AV0) must be ordered separately.