What this SIRIUS auxiliary contactor does in a panel
The 3RH2140-2BA40 is a SIRIUS auxiliary contactor, size S00, carrying four normally-closed (NC) instantaneous contacts. It switches control signals in a motor starter or relay logic circuit — not the motor power itself, but the feedback and interlock wiring that tells the PLC the main contactor is pulled in or the safety circuit is made. Rated 10 A at both 24 V and 230 V, these NC contacts handle the common control voltages in a 24 VDC panel or a 230 VAC line without a contact derating step. The 4 W closing and holding power on the DC coil means the PLC output or relay driving it needs to source at least that — a standard 24 VDC digital output handles it easily. The contacts are rated for 30,000,000 typical mechanical operations — this is a relay-grade life, not a power-contactor life. It fits applications where the auxiliary circuit cycles with every machine cycle, not just on fault events.
Panel fit: DIN rail, clearances, and mounting position
That 6 mm side gap is tight — adjacent devices can sit nearly flush, but the arc chamber needs that 6 mm to vent.
Lifecycle and sourcing: current production, quoted to order
The 3RH2140-2BA40 carries a product extension for auxiliary switches, meaning it accepts add-on contact blocks if the four built-in NC contacts aren't enough. That extension is a standard SIRIUS accessory — no special adapter needed.