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Siemens 3RK4340-3MR51-0BA0 — Motor Starters

Siemens 3RK4340-3MR51-0BA0 SIRIUS Motor Starter, 8 A AC-3

MPN3RK4340-3MR51-0BA0

Siemens SIRIUS 3RK4340-3MR51-0BA0 motor starter MCU, I/O controlled direct starter, 8 A AC-3 at 400 V, Class 10 bimetal overload, IP55, 340-440 V operating voltage, 20.4-26.4 V DC control supply.

Siemens 3RK4340-3MR51-0BA0 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RK4340-3MR51-0BA0 — Identification
ParameterValue
Product designationmotor starter MCU, I/O controlled
Main circuit poles3
BrandSIRIUS
Product design / constructiondirect starter
Reference designation (IEC 81346-2)Q
3RK4340-3MR51-0BA0 — Protection & Tripping
ParameterValue
Trip classCLASS 10
Overload release setting range (current)5.5 ... 8 A
Duty / utilization type (IEC 60947-6-2)1
3RK4340-3MR51-0BA0 — Contacts & Control
ParameterValue
Switching contact typeelectromechanical
3RK4340-3MR51-0BA0 — Communication
ParameterValue
AS-Interface protocol supportNo
3RK4340-3MR51-0BA0 — Mechanical & Connection
ParameterValue
Main circuit connection typescrew-type terminals
Mounting position+/-180° rotation possible on vertical mounting surface; can be tilted forward and backward by +/- 22.5° on vertical mounting surface
Width182 mm
Height220 mm
Depth145 mm

Product details

IP55 enclosure and mounting flexibility for panel integration

The 3RK4340-3MR51-0BA0: Rated IP55, the unit is protected against dust ingress and water jets — suitable for installation in washdown areas or enclosures without a sealed cabinet door, provided the cable glands are properly torqued.

Motor duty and ambient limits for the application engineer

The Class 10 trip curve means the bimetal element will not trip during a normal acceleration of 5–10 seconds. Maximum operating frequency is 80 operations per hour — this is a duty-cycle limit for the electromechanical contactor and bimetal reset time, not a switching frequency ceiling.

Lifecycle and compliance — active production, clean paperwork

Substance prohibitance compliance is dated 05/01/2012, aligning with RoHS and REACH requirements for the European market. The reference code per IEC 81346-2 is Q, classifying it as a switching device in the functional plant hierarchy.

Frequently asked questions

What is the AC-3 motor rating of 3RK4340-3MR51-0BA0?

The AC-3 rating is 8 A at 400 V, which covers direct-on-line starting of standard three-phase squirrel-cage motors up to approximately 4 kW at 400 V. The AC-1 general-purpose rating is also 8 A at 400 V.

What compliance documentation does Siemens provide for 3RK4340-3MR51-0BA0?

The part carries a substance prohibitance compliance date of 05/01/2012, indicating RoHS and REACH conformity for the European market. The reference code per IEC 81346-2 is Q, classifying it as a switching device in plant documentation.

MPN
3RK4340-3MR51-0BA0