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Siemens 3RH2122-2XF40-0LB2 — Contactors

Siemens SIRIUS 3RH2122-2XF40-0LB2 Contactor Relay, 72-125 V

MPN3RH2122-2XF40-0LB2
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Siemens SIRIUS 3RH2122-2XF40-0LB2 contactor relay for railway applications, Size S00, coil 72-125 V DC, varistor surge suppressor, 2 instantaneous contacts, screw and snap-on mounting on 35 mm DIN rail.

Siemens 3RH2122-2XF40-0LB2 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RH2122-2XF40-0LB2 — Identification
ParameterValue
Contactor frame sizeS00
3RH2122-2XF40-0LB2 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated value @ 400 V3 A
Rated value @ 500 V2 A
Rated value @ 690 V1 A
Rated value @ 230 V10 A
Rated value @ 24 V10 A
Rated value @ 60 V4.7 A
Rated value @ 110 V3 A
Rated value @ 220 V1.2 A
3RH2122-2XF40-0LB2 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RH2122-2XF40-0LB2 — Contacts & Poles
ParameterValue
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RH2122-2XF40-0LB2 — Connection & Mounting
ParameterValue
Conductor cross-section, solid or stranded2x (0,5 ... 4 mm²)
Conductor cross-section, finely stranded w/ ferrule2x (0.5 ... 2.5 mm²)
Mounting methodscrew and snap-on mounting onto 35 mm DIN rail
Side-by-side mountingYes
3RH2122-2XF40-0LB2 — Durability
ParameterValue
Durability (operating cycles, typ.)30 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RH2122-2XF40-0LB2 — Environmental
ParameterValue
Operating temperature range-40 ... +70 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RH2122-2XF40-0LB2 — Mechanical
ParameterValue
Width45 mm
Height70 mm
Depth73 mm

Product details

Integrator note — railway contactor relay

The Siemens SIRIUS 3RH2122-2XF40-0LB2 is a contactor relay designed for railway applications. Coil rated 72-125 V DC with a varistor surge suppressor built in — that varistor clamps the coil's turn-off spike, so no external free-wheel diode needed on the DC rail. Holding current averages 7 mA; inrush peak hits 1.1 A. Two instantaneous contacts handle the switching.

Mounting and fit

Size S00 body: 73 mm deep, 45 mm wide, 70 mm tall.

Switching performance and ratings

Arcing time 10-15 ms; DC switching times 25-45 ms. Contact ratings across the voltage range: 10 A at 24 V DC, 4.7 A at 60 V DC, 3 A at 110 V DC, 1.2 A at 220 V DC, 10 A at 230 V AC, 3 A at 400 V AC, 0.5 A at 440 V AC, 2 A at 500 V AC, 0.26 A at 600 V AC, 1 A at 690 V AC. Mechanical life typical 30 million operations.

Lifecycle stage is current. Substance prohibitance date 10/01/2009. Relative humidity minimum 10 %.

Frequently asked questions

What is the closest functional second-source — 3RH2122-1BW40?

The 3RH2122-1BW40 is a peer in the same SIRIUS contactor relay family, but the 2XF40-0LB2 carries a 72-125 V DC coil with a varistor suppressor, while the 1BW40 may differ in coil voltage and suppressor type. Verify coil compatibility before substitution.

Will 3RH2122-2XF40-0LB2 drop into a panel specified around 3RH2122-1BW40 without rewiring?

Both share the same SIRIUS S00 footprint and DIN-rail mounting, so mechanical fit is identical. Electrical fit depends on coil voltage and suppressor — the 2XF40-0LB2 uses a 72-125 V DC coil with varistor; if the 1BW40 has a different coil rating, rewiring may be needed.

What compliance documentation does this brand provide?

The part carries a substance prohibitance date of 10/01/2009, indicating RoHS compliance. Standard Siemens SIRIUS documentation includes CE and UL declarations — request the specific certificate with your RFQ.

MPN
3RH2122-2XF40-0LB2