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Siemens 3RV2121-4EA10 — Motor Protection Circuit Breakers (MPCB)

Siemens 3RV2121-4EA10 SIRIUS Motor Protection Circuit Breake

MPN3RV2121-4EA10
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Siemens SIRIUS 3RV2121-4EA10, motor protection circuit breaker with overload relay function, Class 10 trip class, 65 mm width, screw and snap-on 35 mm DIN rail mounting.

Siemens 3RV2121-4EA10 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RV2121-4EA10 — Identification
ParameterValue
SeriesSIRIUS
Product designationCircuit breaker
Frame sizeS0
3RV2121-4EA10 — Electrical
ParameterValue
Rated operational current (Ie)32 A
Rated voltage20 ... 690 V
Rated voltage, AC-3 (max.)690 V
Rated frequency50 ... 60 Hz
Rated insulation voltage (Ui), pollution degree 3690 V
Rated impulse withstand voltage (Uimp)6 kV
Number of poles3
Power loss (AC, hot)13.25 W
Power loss, per pole (AC, hot)4.4 W
3RV2121-4EA10 — Protection & Tripping
ParameterValue
Overload release setting range27 ... 32 A
Instantaneous short-circuit trip current400 A
Trip classCLASS 10
Breaking capacity at 240 V (AC)100 kA
Breaking capacity at 400 V (AC)55 kA
Breaking capacity at 500 V (AC)10 kA
Breaking capacity at 690 V (AC)4 kA
Breaking capacity at 240 V100 kA
Breaking capacity at 690 V2 kA
Short-circuit trip typemagnetic
Overload release typethermal
Short-circuit protectionYes
Phase-failure detectionYes
Ground-fault detectionNo
Auxiliary switch extendableYes
3RV2121-4EA10 — Endurance & Switching
ParameterValue
Endurance, main contacts (typ.)100 000
Endurance, auxiliary contacts (typ.)100 000
Switching frequency, AC-3 (max.)15 1/h
Auxiliary CO (changeover) contacts0
3RV2121-4EA10 — Connections
ParameterValue
Main-circuit terminal typescrew-type terminals
Main-circuit connector arrangementTop and bottom
Conductor cross-section, solid / stranded2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)
Conductor cross-section, finely stranded with ferrule2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)
Conductor range, AWG (main contacts)2x (16 ... 12), 2x (14 ... 8)
3RV2121-4EA10 — Mechanical
ParameterValue
Height97 mm
Width65 mm
Depth97 mm
Mounting methodscrew and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715
Mounting positionany
3RV2121-4EA10 — Environmental
ParameterValue
Operating temperature-20 ... +60 °C
Storage temperature-50 ... +80 °C
Transport temperature-50 ... +80 °C
Relative humidity (operation)10 ... 95 %
Max. installation altitude2 000 m
3RV2121-4EA10 — Specifications
ParameterValue
Design Of The ProductFor motor protection with overload relay function

Product details

What this SIRIUS breaker does

The Siemens 3RV2121-4EA10 is a SIRIUS-brand motor protection circuit breaker that integrates the overload relay function directly into the breaker body — one device handles both short-circuit and thermal overload protection for a motor branch circuit.

Breaking capacity and voltage ratings

At 400 V rated value, the interrupting capacity is 25 kA — enough to handle most industrial panel fault currents without requiring an upstream current-limiting fuse. The unit carries ratings at 240 V (100 kA), 480 V (32 A continuous), 600 V (32 A continuous), and 500 V (5 kA) — cover the common North American and European voltage tiers.

Main contact terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire, terminated with M4 screws.

Frequently asked questions

Where can I buy 3RV2121-4EA10?

Sourced and quoted to order against an RFQ through independent distribution channels; availability and current pricing are confirmed at quote time.

What is the closest functional second-source for 3RV2121-4EA10?

The 3RV2021-4NA25 is a SIRIUS peer with similar motor protection function and Class 10 trip, but verify the breaking capacity and clearance dimensions for your specific voltage — the 3RV2121-4EA10 carries a 65 mm width versus the 3RV2021-4NA25's different form factor, so panel cutout compatibility must be checked.

Will 3RV2121-4EA10 drop into a panel specified for 3RV2021-4NA25 without rewiring?

Not without checking — the 3RV2121-4EA10 has a 65 mm width and specific clearance requirements (50 mm up/down, 30 mm side), which may differ from the 3RV2021-4NA25's footprint. Terminal wire sizes are identical (2x 0.5–2.5 mm²), but the mounting hole pattern and DIN rail clip position should be verified against the existing panel layout.

MPN
3RV2121-4EA10