What it is and what it does
The Siemens SIRIUS 3RH1131-1BB40-0TK1-ZX95 is an auxiliary contactor — a switching device that extends the contact count of a main contactor or provides isolated signal feedback in a control circuit. It carries 3 instantaneous normally-open contacts rated for 10 A at 24 V, with a 24 VDC coil drawing 3.2 W for both closing and holding. The size S00 footprint (45 mm wide, 57.5 mm tall, 72 mm deep) fits standard DIN-rail enclosures alongside S00 contactors and overload relays.
Ratings and what they mean for fit
The 24 VDC coil is the control voltage — verify your PLC or relay output matches before wiring. The 3.2 W holding power is continuous; the coil driver must sink that current without overheating. The 10 A at 24 V rating applies to the auxiliary contacts; for higher AC voltages the rating drops (6 A at 230 V, 3 A at 400 V, 1 A at 690 V), so the contact load must be checked against the actual circuit voltage. The 6 kV surge voltage resistance (rated impulse withstand) means the contacts can handle typical industrial transients without welding — important for inductive loads like small contactor coils or solenoid valves.
Mounting and wiring
Mounts via screw or snap-on onto DIN rail. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward. The screw terminals accept solid conductors: 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or 2x 4 mm² (or AWG equivalents: 2x 20–16, 2x 18–14, 1x 12). IP20 front protection keeps it inside a closed panel.