ASIsafe safety monitor with one enabling circuit
The Siemens 3RK1105-1AE04-2CA0 is an ASIsafe extended safety monitor with one enabling circuit and one safe output relay (F-RO). The monitor type 3, version 3 hardware supports Category 4 per EN 954-1, PL e per EN ISO 13849-1, and SIL 3 per IEC 61508 — the top end of the safety integrity scale for this class, meaning it can handle the most demanding risk-reduction requirements in a machine safety circuit. Response time is 40 ms maximum.
Output relay ratings and switching capacity
The safe output relay is rated for DC-12 (DC-1) at 24 V at 3 A, and AC-12 at 250 V at 3 A. These are the resistive-load curves — the relay switches the enabling circuit cleanly at those levels. The control-side enabling circuit draws 1 A at 24 V, with lower draws at 115 V (0.1 A) and 230 V (0.05 A). If you're driving an inductive load like a contactor coil downstream, factor in the inrush; the AC-12 rating covers resistive loads, not the AC-15 motor-coil curve.
AS-Interface integration and wiring
AS-Interface protocol is supported natively — the monitor communicates over the AS-i safety bus, which means it reports diagnostics and status back to the AS-i master without separate safety wiring. The inputs and outputs terminate on screw terminals with removable terminal blocks, so you can pre-wire the panel and plug the monitor in later.
Environmental limits and protection class
IP20 protection means it's suitable for a clean, dry control cabinet — no washdown, no dust ingress. The IP20 rating is standard for panel-mounted safety relays; if the cabinet sees condensation or washdown, the monitor needs to be behind a sealed enclosure door.