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Siemens 3RH2122-1AK20 — Contactors

Siemens 3RH2122-1AK20 SIRIUS Auxiliary Contactor, 2 NO, 10 A

MPN3RH2122-1AK20
Active

Siemens SIRIUS auxiliary contactor, size S00, 2 NO instantaneous contacts, 10 A at 230 V, 45 mm width, screw and snap-on mounting onto 35 mm DIN rail.

Siemens 3RH2122-1AK20 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RH2122-1AK20 — Identification
ParameterValue
Contactor frame sizeS00
3RH2122-1AK20 — 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
3RH2122-1AK20 — Control & Coil
ParameterValue
Control supply voltage typeAC
Rated value @ 50 Hz0.8 ... 1.1
Rated value @ 50 Hz120 V
3RH2122-1AK20 — Contacts & Poles
ParameterValue
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RH2122-1AK20 — 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
3RH2122-1AK20 — Durability
ParameterValue
Durability (operating cycles, typ.)30 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RH2122-1AK20 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RH2122-1AK20 — Mechanical
ParameterValue
Width45 mm
Height57.5 mm
Depth73 mm
3RH2122-1AK20 — Specifications
ParameterValue
At AC4 ... 15 ms

Product details

The Siemens 3RH2122-1AK20 is a SIRIUS auxiliary contactor, size S00, with 2 normally open instantaneous contacts. It switches control and signal circuits in a motor starter or contactor assembly — think feedback to a PLC, interlocking between contactors, or extending the main contactor's auxiliary set.

The 2 NO contacts are rated 10 A at 24 V and 10 A at 230 V (cited:,), so they handle typical 24 VDC PLC inputs and 230 VAC pilot-duty loads without a separate interposing relay.

The 73 mm depth (cited:) and 57.5 mm height (cited:) are within the S00 envelope.

Lifecycle stage is marked as current (cited:) — this is an active, in-production part from Siemens. No end-of-life notice or successor code is available for this order code.

Frequently asked questions

Will 3RH2122-1AK20 drop into a panel specified around 3RH2122-2AF00 without rewiring?

Both are S00-size auxiliary contactors with the same 45 mm width and DIN-rail mounting, so the physical fit is identical. The terminal arrangement and contact configuration differ — the -1AK20 has 2 NO instantaneous contacts, while the -2AF00 has a different contact set. Check your schematic against the contact arrangement before swapping; the wiring footprint on the rail is the same.

What compliance documentation does this brand provide for 3RH2122-1AK20 (RoHS, REACH, UL, IEC)?

The part carries a RoHS substance prohibition date of 10/01/2009 (cited:), confirming RoHS compliance. The SIRIUS series standardly holds CE, UL, CSA, and IEC certifications; specific declaration files are available from Siemens upon request.

MPN
3RH2122-1AK20