The Siemens 3SK1111-2AB30-0AX0 is a SIRIUS 3SK1 Standard basic unit safety relay — three normally-open enabling circuits and one normally-closed signaling contact, all on a 24 V AC/DC coil. The spring-loaded push-in terminals (painted PCB variant) save wiring time in a panel; strip and push, no screwdriver needed. This is the basic unit, so it handles the core safety logic without expansion modules — you wire your e-stop or guard switch contacts directly to the inputs and the enabling circuits go straight to the contactors or drives you need to drop.
Three NO contacts rated for safety enabling circuits — that means three independent paths you can use to drop power to separate zones or loads, all controlled by the same safety input condition. The single NC contact is a signaling mirror, not a safety path; it tells the PLC or HMI that the relay has picked up. Coil is 24 V AC/DC, so it works on either supply without rewiring — common for panels that mix control transformers and battery-backed DC supplies.
RoHS compliant since 05-11-2012.