SIRIUS contactor relay, DC coil, size S00
The Siemens 3RH6122-1BC40 is a SIRIUS contactor relay in size S00, with a 2 NO + 2 NC contact configuration and a DC 30 V coil, terminated via screw terminals.
Contact configuration and coil voltage
The 2 NO + 2 NC contact arrangement gives you two normally-open and two normally-closed auxiliary contacts in a single relay, covering most feedback and interlocking needs in a motor starter or control circuit. The DC 30 V coil suits applications where the control voltage is a low-voltage DC bus, common in PLC-driven panels or battery-backed systems — confirm your control supply matches 30 VDC before wiring.