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Siemens 3RK4320-3MR51-0BA0 — Motor Starters

Siemens 3RK4320-3MR51-0BA0 SIRIUS Motor Starter, 8 A AC-3

MPN3RK4320-3MR51-0BA0

Siemens SIRIUS motor starter MCU for AS-Interface, 3RK4320-3MR51-0BA0, direct starter design, 8 A at AC-3 400 V, Trip Class 10, IP55, DC control supply 20.4-26.4 V.

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

3RK4320-3MR51-0BA0 — Identification
ParameterValue
Product designationmotor starter MCU for AS-Interface
Main circuit poles3
BrandSIRIUS
Product design / constructiondirect starter
Reference designation (IEC 81346-2)Q
3RK4320-3MR51-0BA0 — Protection & Tripping
ParameterValue
Trip classCLASS 10
Overload release setting range (current)5.5 ... 8 A
Duty / utilization type (IEC 60947-6-2)1
3RK4320-3MR51-0BA0 — Contacts & Control
ParameterValue
Switching contact typeelectromechanical
3RK4320-3MR51-0BA0 — Communication
ParameterValue
AS-Interface protocol supportYes
3RK4320-3MR51-0BA0 — 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

Rated 8 A at AC-3 duty at 400 V, it switches standard three-phase squirrel-cage induction motors up to that current — the AC-3 rating is the load-bearing figure for motor starting, not the resistive AC-1 number. The control supply accepts 20.4 to 26.4 V DC, and the main circuit operating voltage range is 340 to 440 V AC at 50/60 Hz. Three poles serve the main current circuit. IP55 enclosure rating means the unit is dust-protected and withstands water jets — suitable for installation in industrial environments where washdown or airborne particulates are present, but not for submersion or high-pressure washdown zones that would demand IP65 or higher.

AS-Interface integration and mounting

This motor starter communicates via the AS-Interface protocol, with no PROFIBUS DP or PROFINET on board — the bus interface is dedicated to AS-i, so the part fits into an AS-i network segment without a gateway for the motor starter itself. Dimensions are 182 mm wide, 220 mm high, and 145 mm deep. Short-circuit protection is provided by circuit-breakers (not fuses), and the unit is designed for a single motor assignment.

Frequently asked questions

Where can I buy the Siemens 3RK4320-3MR51-0BA0?

This part is sourced to order against an RFQ through independent distribution. Submit a request for quote to confirm availability and current pricing.

Does the 3RK4320-3MR51-0BA0 support PROFINET or PROFIBUS?

No — this unit supports AS-Interface protocol only. It does not carry PROFIBUS DP or PROFINET interfaces.

MPN
3RK4320-3MR51-0BA0