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Siemens 3RH2122-2XB40-0LA2 — Contactors

Siemens 3RH2122-2XB40-0LA2 SIRIUS Contactor Relay, 24-34 VDC

MPN3RH2122-2XB40-0LA2
Active

Siemens SIRIUS contactor relay, size S00, 2 instantaneous NO contacts, 24-34 VDC coil with varistor, screw and snap-on 35 mm DIN rail, 73 mm depth, 45 mm width.

$36.83Ref. price · indicative, final on quote
Siemens 3RH2122-2XB40-0LA2 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RH2122-2XB40-0LA2 — Identification
ParameterValue
Contactor frame sizeS00
3RH2122-2XB40-0LA2 — 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
3RH2122-2XB40-0LA2 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RH2122-2XB40-0LA2 — Contacts & Poles
ParameterValue
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RH2122-2XB40-0LA2 — 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
3RH2122-2XB40-0LA2 — Durability
ParameterValue
Durability (operating cycles, typ.)30 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RH2122-2XB40-0LA2 — Environmental
ParameterValue
Operating temperature range-40 ... +70 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RH2122-2XB40-0LA2 — Mechanical
ParameterValue
Width45 mm
Height70 mm
Depth73 mm

Product details

Railway-rated contactor relay, S00 frame

It carries 2 instantaneous normally-open contacts and a 24-34 VDC rated coil with an integrated varistor surge suppressor.

Coil and contact ratings for the railway environment

Coil pick-up is rated at 24-34 VDC with an inrush peak of 2.3 A and a holding current mean value of 40 mA. The contactor relay switches resistive loads up to 10 A at 24 VDC and 10 A at 230 VAC; at 400 VAC the rating drops to 3 A. Arcing time runs 10-15 ms, and the mechanical life of the contactor typical is 30 million operations. The varistor suppressor is designed into the coil circuit, so no external suppression module is needed for DC switching.

Side-by-side mounting is permitted, which matters when packing multiple relays in a row on the rail.

Environmental range and wiring

Relative humidity minimum is 10 %. The contactor relay is rated for DC switching with a time constant of 25-45 ms at DC.

Frequently asked questions

Where can I buy 3RH2122-2XB40-0LA2?

This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.

What is the closest functional alternative to 3RH2122-2XB40-0LA2?

The 3RH2122-1BA40 is a sibling in the same SIRIUS S00 family but lacks the varistor suppressor and the railway designation. It will drop into the same DIN-rail footprint and wiring pattern, but the coil suppression and environmental ratings differ — verify the application before substituting.

What are the key dimensions of 3RH2122-2XB40-0LA2?

Depth is 73 mm, width is 45 mm, height is 70 mm. Clearances: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side.

What compliance documentation does this part carry?

The substance prohibitance date of 10/01/2009 confirms RoHS compliance. As a Siemens SIRIUS product, it is designed to relevant IEC and EN standards for contactors and railway rolling stock applications.

MPN
3RH2122-2XB40-0LA2