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Siemens 3RK4320-3BR51-0BA0 — Motor Starters

Siemens 3RK4320-3BR51-0BA0 SIRIUS Motor Starter, 0.8 A AC-3

MPN3RK4320-3BR51-0BA0

Siemens SIRIUS 3RK4320-3BR51-0BA0 motor starter, direct starter design, 0.8 A at 400 V AC-3, AS-Interface bus communication, IP55, Class 10 trip, 3-pole, 145 x 182 x 220 mm.

Siemens 3RK4320-3BR51-0BA0 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RK4320-3BR51-0BA0 — Identification
ParameterValue
Product designationmotor starter MCU for AS-Interface
Main circuit poles3
BrandSIRIUS
Product design / constructiondirect starter
Reference designation (IEC 81346-2)Q
3RK4320-3BR51-0BA0 — Protection & Tripping
ParameterValue
Trip classCLASS 10
Overload release setting range (current)0.55 ... 0.8 A
Duty / utilization type (IEC 60947-6-2)1
3RK4320-3BR51-0BA0 — Contacts & Control
ParameterValue
Switching contact typeelectromechanical
3RK4320-3BR51-0BA0 — Communication
ParameterValue
AS-Interface protocol supportYes
3RK4320-3BR51-0BA0 — 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

Bus integration and supply

The 3RK4320-3BR51-0BA0: The unit communicates over AS-Interface (AS-i) protocol, not PROFIBUS or PROFINET — confirm your network master supports AS-i before specifying. Control supply is 20.4–26.4 V DC, separate from the motor power circuit. The 0.8 A AC-3 rating at 400 V sets the maximum motor FLA this starter can switch; size the motor branch circuit so the full-load current stays under this figure.

Mounting and enclosure fit

IP55 rated — the housing is dust-protected and splash-proof, suitable for panel-mount in washdown areas or outdoor cabinets, but not for submerged or high-pressure spray zones. Dimensions are 145 mm deep, 182 mm wide, 220 mm tall — check the enclosure backplate layout for clearance on the AS-i cable entry. The bimetal overload is field-adjustable; the trip class is fixed at Class 10.

Lifecycle and procurement

RoHS compliance date is 05/01/2012, meaning it meets the EU RoHS substance restrictions effective from that date.

Frequently asked questions

What is the rated current of 3RK4320-3BR51-0BA0 at 400 V AC-3?

This is the motor-switching current for standard induction motors; the AC-1 (resistive) rating is also 0.8 A at 400 V.

What communication protocol does this motor starter use?

AS-Interface (AS-i). It does not support PROFIBUS DP or PROFINET — the network master must be AS-i capable.

MPN
3RK4320-3BR51-0BA0