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Siemens 3RV2121-4AA10 — Motor Protection Circuit Breakers (MPCB)

Siemens SIRIUS 3RV2121-4AA10 Motor Protection Circuit Breake

MPN3RV2121-4AA10
Active

Siemens SIRIUS motor protection circuit breaker with overload relay function, 3RV2121-4AA10, 16 A rated at 480/600 V, 25 kA breaking capacity at 400 V, Class 10 trip, screw terminals, 65 mm width.

Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

3RV2121-4AA10 — Identification
ParameterValue
SeriesSIRIUS
Product designationCircuit breaker
Frame sizeS0
3RV2121-4AA10 — Electrical
ParameterValue
Rated operational current (Ie)16 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)9.25 W
Power loss, per pole (AC, hot)3.1 W
3RV2121-4AA10 — Protection & Tripping
ParameterValue
Overload release setting range10 ... 16 A
Instantaneous short-circuit trip current208 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
3RV2121-4AA10 — 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
3RV2121-4AA10 — 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)
3RV2121-4AA10 — 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
3RV2121-4AA10 — 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
3RV2121-4AA10 — Specifications
ParameterValue
Design Of The ProductFor motor protection with overload relay function

Product details

For motor sizing, this corresponds to 2 hp at 230 V, 1 hp at 110/120 V, and 3 hp at 200/208 V, per the datasheet. Breaking capacity is 100 kA at 240 V, 25 kA at 400 V, 5 kA at 500 V, and 2 kA at 690 V. This is the SCCR (short-circuit current rating) the panel designer needs for the branch circuit. The rated voltage range spans 20 to 690 V, covering standard low-voltage networks. Maximum switching frequency under AC-3 duty (motor starting) is 15 operations per hour — adequate for a motor that starts a few times per shift, not for a high-cycling application like a rapid-reversing conveyor.

Dimensions are 65 mm width, 97 mm depth, 97 mm height. Required clearances: 50 mm upwards and downwards, 30 mm at the sides, 0 mm forwards and backwards — so it can be stacked tightly front-to-back but needs breathing space above and below for arc quenching and thermal dissipation. Main circuit terminals are screw-type, accepting 2× (0.5 to 1.5 mm²) or 2× (0.75 to 2.5 mm²) solid or stranded conductors. The main contact screws are M4 size. The storage range is wider — that limit governs handling, not running.

For fuse backup coordination: the maximum fuse ratings at various voltages are gL/gG 63 A at 400 V, gL/gG 50 A at 500 V, and gL/gG 40 A at 690 V. These are the upstream fuse sizes that allow the breaker to clear a fault within its rated breaking capacity.

MPN
3RV2121-4AA10