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Siemens 3RH2140-2MB40-0KT0 — Contactors

Siemens 3RH2140-2MB40-0KT0 SIRIUS Coupling Relay, 24 VDC

MPN3RH2140-2MB40-0KT0
Active

Siemens SIRIUS 3RH2140-2MB40-0KT0 coupling relay, size S00, 24 VDC coil, 4 NO instantaneous contacts, 10 A rated current at 24 V, screw and snap-on mounting on 35 mm DIN rail.

Siemens 3RH2140-2MB40-0KT0 datasheet (PDF)
StockContact for availability
Lead time3-5 Days wk
MOQ1 pcs
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026
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Specifications

Identification

3RH2140-2MB40-0KT0 — Identification
ParameterValue
Contactor frame sizeS00

Ratings & Performance

3RH2140-2MB40-0KT0 — 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

Control & Coil

3RH2140-2MB40-0KT0 — Control & Coil
ParameterValue
Control supply voltage typeDC

Contacts & Poles

3RH2140-2MB40-0KT0 — Contacts & Poles
ParameterValue
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)

Connection & Mounting

3RH2140-2MB40-0KT0 — 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 standard mounting rail

Durability

3RH2140-2MB40-0KT0 — Durability
ParameterValue
Durability (operating cycles, typ.)30 000 000

Environmental

3RH2140-2MB40-0KT0 — Environmental
ParameterValue
Operating temperature range-25 ... +50 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m

Mechanical

3RH2140-2MB40-0KT0 — Mechanical
ParameterValue
Width45 mm
Height70 mm
Depth73 mm

Specifications

3RH2140-2MB40-0KT0 — Specifications
ParameterValue
At AC10 000 1/h

Product details

Coupling relay for auxiliary circuit switching

The Siemens 3RH2140-2MB40-0KT0 is a SIRIUS coupling relay designed to switch auxiliary circuits in control panels.

Contact ratings and switching capability

This voltage-dependent current curve means the relay is best suited for low-voltage auxiliary loads — PLC outputs, signal lamps, solenoid valves — rather than high-voltage power switching.

Coil drive and environmental limits

The 24 VDC coil picks up at 85 % of rated voltage (20.4 V) and drops out at 185 % (44.4 V) — the wide dropout margin prevents nuisance drop-out on a sagging bus. Coil power is a constant 1.6 W DC, so no inrush peak to size the power supply for. Pollution degree 3 means it tolerates conductive pollution in industrial control cabinets — no conformal coating required for typical panel environments.

Mounting and clearance requirements

These spacings ensure arc quenching and heat dissipation — pack tighter and the relay may overheat or flash over.

No auxiliary switch extension is available on this variant — the 4 NO contacts are fixed. For applications needing additional signaling, a separate auxiliary contact block from the SIRIUS range would be added externally.

Frequently asked questions

What is the 3RH2140-2MB40-0KT0 used for?

It is a coupling relay for switching auxiliary circuits — typically used to interface PLC digital outputs with higher-current loads, to isolate control signals from power circuits, or to multiply contact capacity in a control panel. The 4 NO contacts handle up to 10 A at 24 VDC or 230 VAC.

What compliance documentation does Siemens provide for 3RH2140-2MB40-0KT0?

The relay is RoHS compliant with a substance prohibition date of October 1, 2009. Standard Siemens documentation includes a CE declaration of conformity and a UL/CSA file number — these are available on request with the order.

MPN
3RH2140-2MB40-0KT0