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Siemens 3RA2120-4BD27-0FB4 — Motor Starters

Siemens 3RA2120-4BD27-0FB4 SIRIUS Direct Starter, 20 A AC-3

MPN3RA2120-4BD27-0FB4
Active

Siemens SIRIUS 3RA2120-4BD27-0FB4 direct online starter, Size S0, 20 A AC-3 at 400 V, Class 10 trip, screw terminals, for 60 mm busbar systems.

Siemens 3RA2120-4BD27-0FB4 datasheet (PDF)
Source DocumentedChannel stated on listing & quote
Condition PhotosReal unit photos / video on request
WhatsApp AnswersFast human replies for machine-down parts
Worldwide DispatchDHL/FedEx — transit quoted per order
Independent China distributor & sourcing agent· Listing updated Sep 2026

Specifications

3RA2120-4BD27-0FB4 — Identification
ParameterValue
Product designationDirect (on-line) starter
Main circuit poles3
BrandSIRIUS
Load feeder sizeS0
Product design / constructionfor 60 mm busbars
Circuit-breaker sizeS0
Included contactor (type)3RT2027-1FB40
Included circuit-breaker (type)3RV2021-4BA10
Included link module (type)3RA2921-1BA00
3RA2120-4BD27-0FB4 — Ratings & Performance
ParameterValue
Rated motor power at 400 V7 500 kW
Rated voltage at AC-3, max.690 V
Rated motor power at 460/480 V (hp)15 hp
Rated current at 480 V20 A
Rated current at 600 V20 A
Rated operating frequency50 ... 60 Hz
Rated impulse withstand voltage (Uimp)6 kV
Rated insulation voltage Ui (AC, pollution degree 3)690 V
3RA2120-4BD27-0FB4 — Protection & Tripping
ParameterValue
Trip classCLASS 10
Short-circuit protectionYes
Rated short-circuit current at 400 V (IEC 60947-4-1)150 000 A
Overload release setting range (current)13 ... 20 A
Overload release typethermal (bimetallic)
Short-circuit trip typemagnetic
Duty / utilization type (IEC 60947-6-2)2
3RA2120-4BD27-0FB4 — Contacts & Control
ParameterValue
Rated value24 ... 24 V
Control supply voltage typeDC
Auxiliary switch extensionYes
Switching contact typeelectromechanical
3RA2120-4BD27-0FB4 — Communication
ParameterValue
AS-Interface protocol supportNo
3RA2120-4BD27-0FB4 — Mechanical & Connection
ParameterValue
Mounting / fastening methodfor snapping onto 60 mm busbar systems
Mounting positionvertical
Width45 mm
Height260 mm
Depth165 mm
3RA2120-4BD27-0FB4 — Environmental
ParameterValue
Operating temperature range-20 ... +60 °C
Storage temperature range-50 ... +80 °C
Transport temperature range-50 ... +80 °C
Shock resistance (IEC 60068-2-27)6g / 11 ms

Product details

Busbar snap-on and panel fit

The 3RA2120-4BD27-0FB4: Mounts by snapping onto 60 mm busbar systems — no DIN rail needed. The 45 mm width and 165 mm depth fit into a standard S0 feeder slot; vertical mounting position only, with 50 mm clearance above and 20 mm at the side for cooling and wiring access. The supplied contactor is a 3RT2027-1FB40, and the link module is 3RA2921-1BA00 — pre-assembled as a single order code, so no separate sourcing for the contactor and overload.

Lifecycle and sourcing — active, quoted to order

Sourced through authorized distribution against the BOM quantity; availability and pricing confirmed at RFQ time.

Frequently asked questions

What is the AC-3 current rating at 400 V for this starter?

That's the motor-switching current that governs contact life and overload setting — not the thermal continuous current, which is higher.

Does this starter include the contactor and overload relay, or do I need to buy them separately?

It ships as a complete direct-on-line starter with the 3RT2027-1FB40 contactor and the 3RA2921-1BA00 link module pre-assembled. One order code, one unit.

MPN
3RA2120-4BD27-0FB4