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Siemens 3RV2321-4BC20 — Motor Protection Circuit Breakers (MPCB)

Siemens 3RV2321-4BC20 SIRIUS Circuit Breaker, 55 kA at 400 V

MPN3RV2321-4BC20
Active

Siemens SIRIUS circuit breaker, 3RV2321-4BC20, for starter combinations, 55 kA breaking capacity at 400 V AC, screw and snap-on mounting on 35 mm DIN rail.

$38.10Ref. price · indicative, final on quote
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

3RV2321-4BC20 — Identification
ParameterValue
SeriesSIRIUS
Product designationCircuit breaker
Frame sizeS0
3RV2321-4BC20 — Electrical
ParameterValue
Rated operational current (Ie)20 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)10.5 W
Power loss, per pole (AC, hot)3.5 W
3RV2321-4BC20 — Protection & Tripping
ParameterValue
Instantaneous short-circuit trip current260 A
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
Short-circuit protectionYes
Phase-failure detectionNo
Ground-fault detectionNo
Auxiliary switch extendableYes
3RV2321-4BC20 — 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
3RV2321-4BC20 — Connections
ParameterValue
Main-circuit terminal typespring-loaded terminals
Main-circuit connector arrangementTop and bottom
Conductor cross-section, solid / stranded2x (1 ... 10 mm²)
Conductor cross-section, finely stranded with ferrule2x (1 ... 6 mm²)
3RV2321-4BC20 — Mechanical
ParameterValue
Height119 mm
Width45 mm
Depth97 mm
Mounting methodscrew and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715
Mounting positionany
3RV2321-4BC20 — 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
3RV2321-4BC20 — Specifications
ParameterValue
Design Of The ProductFor starter combinations

Product details

The breaker is rated for motor loads across common North American and IEC voltages: 3 hp at 230 V, 5 hp at 220/230 V, 7.5 hp at 200/208 V, and 10 hp at 460/480 V, so it covers a wide range of fractional-to-mid horsepower induction motors.

The 45 mm width (three module spaces) and 97 mm depth mean it fits a standard gland-plate layout without protruding into cable duct space.

For gL/gG fuse coordination, the maximum fuse rating at 400 V is 63 A, dropping to 50 A at 500 V and 690 V — this matters when the breaker is part of a Type 2 coordinated starter and the upstream fuse must be sized to let the breaker clear the fault. Rated operational voltage spans 20 to 690 V, so it works on 24 V control circuits as well as 480 V and 600 V motor feeds — one part number covers multiple line voltages in the same panel.

Frequently asked questions

How do I get current pricing and availability for 3RV2321-4BC20?

Submit an RFQ through this listing. Pricing and stock are confirmed at quote time through independent distribution channels.

What is the depth of 3RV2321-4BC20?

The depth is 97 mm, with a width of 45 mm and height of 119 mm.

Will 3RV2321-4BC20 drop into a panel specified around 3RV2021-4CA25?

Both are SIRIUS circuit breakers on the same DIN-rail footprint, but the 3RV2321-4BC20 is a higher-current frame (55 kA vs the 3RV2021 series typically lower). Check the panel's available fault current and motor FLA before substituting — the physical mounting is compatible, but the protection curve and interrupting rating differ.

What compliance documentation does Siemens provide for 3RV2321-4BC20?

Siemens SIRIUS products typically carry CE, UL, CSA, and CCC certifications, plus RoHS and REACH declarations. Specific document numbers are confirmed with the order.

MPN
3RV2321-4BC20