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Siemens 3RH6122-1KB40 — Contactors

Siemens 3RH6122-1KB40 SIRIUS Coupling Relay, 24 V DC, 2 NO +

MPN3RH6122-1KB40

Siemens SIRIUS coupling relay, 3RH6122-1KB40, size S00, 24 V DC coil, 2 NO + 2 NC contacts, screw-type terminals, snap-on 35 mm DIN rail mounting.

Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RH6122-1KB40 — Identification
ParameterValue
Contactor frame sizeS00
3RH6122-1KB40 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.6 A
Rated value @ 400 V3 A
Rated value @ 690 V1 A
Rated value @ 230 V10 A
Rated value @ 24 V6 A
Rated value @ 110 V3 A
Rated value @ 220 V1.2 A
3RH6122-1KB40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RH6122-1KB40 — Contacts & Poles
ParameterValue
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RH6122-1KB40 — Connection & Mounting
ParameterValue
Conductor cross-section, solid or stranded2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), 2x 4 mm²
Conductor cross-section, finely stranded w/ ferrule2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)
Mounting methodscrew and snap-on mounting onto 35 mm DIN rail
3RH6122-1KB40 — Durability
ParameterValue
Durability (operating cycles, typ.)30 000 000
3RH6122-1KB40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RH6122-1KB40 — Mechanical
ParameterValue
Width45 mm
Height57.5 mm
Depth73 mm
3RH6122-1KB40 — Specifications
ParameterValue
At AC10 000 1/h

Product details

Its job is to take a 24 V DC control signal and pass it through to downstream logic or loads via 2 normally-open and 2 normally-closed contacts, each rated 6 A at 24 V. The coil holds at 2.8 W DC, with an integrated suppressor diode across the coil to clip the flyback spike when de-energizing — that diode matters if you're driving this from a PLC output or a solid-state source that can't absorb the inductive kick. Snap it onto a 35 mm DIN rail in a control panel; the screw terminals accept up to 2x 4 mm² solid or 2x 2.5 mm² stranded, so it'll land in most European-style marshalling cabinets without adapters.

The size S00 footprint is 45 mm wide by 73 mm deep by 57.5 mm tall.

The contacts are rated for AC-12 and DC-12/DC-13 loads. At 24 V DC the continuous current is 6 A; at 110 V DC it drops to 3 A, at 220 V DC to 1.2 A, and at 690 V AC to 1 A. The 2 NO + 2 NC contact arrangement (22 E designation) is the standard auxiliary block for this frame.

Installation altitude is limited to 2,000 m above sea level without derating. The part is RoHS-compliant per the substance prohibition date of May 1, 2012. No UL or CSA listing is stated in the spec record, but the SIRIUS family typically carries IEC 60947-5-1 certification for auxiliary contactors. The suppressor diode across the coil is a factory-fitted design — no external snubber required for DC switching.

Frequently asked questions

Will 3RH6122-1KB40 drop into a panel designed for 3RH6131-1BF40 without rewiring?

The mechanical footprint is identical — both are size S00, 45 mm wide, snap onto 35 mm DIN rail, and use screw terminals. The wiring pattern differs because the contact arrangement is different (2 NO + 2 NC vs 1 NO + 3 NC). If the panel wiring assumes three NC contacts, you would need to re-terminate the NC circuits.

What compliance documentation does Siemens provide for 3RH6122-1KB40?

The part is RoHS-compliant per the substance prohibition date of May 1, 2012. The SIRIUS family typically carries IEC 60947-5-1 certification for auxiliary contactors. No UL or CSA listing is stated in the spec record.

MPN
3RH6122-1KB40