The Siemens 3RK1903-1CA00 is an F-kit for the DS1-X DOL starter, designed for the ET200S distributed solution local. It enables safety functionality up to Category 4 / PL e according to ISO13849-1 and up to SIL 3 per IEC 62061 — the highest performance level for a single DOL starter without a separate safety relay. The kit bundles an auxiliary switch block, a contact holder with connecting cable, and two contact carriers for the TM interface, so it drops into the existing DS1-X footprint and wiring scheme.
Panel integration and wiring note
The connecting cable between the auxiliary switch block and the contact holder is pre-terminated — no field wiring of the safety chain is required. The two contact carriers plug into the TM (terminal module) interface of the ET200S, so the safety signals are routed through the backplane bus rather than point-to-point. This keeps the panel wiring clean and reduces the chance of a miswire in the safety circuit.