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Siemens 3RT1044-3BD40 — Contactors

Siemens 3RT1044-3BD40 SIRIUS S3 Power Contactor, 30 kW AC-2

MPN3RT1044-3BD40

Siemens SIRIUS S3 power contactor, 3RT1044-3BD40, screw-type terminals, AC-2 rated 30 kW at 400 V, AC-4 55 A at 400 V, screw and snap-on mounting onto 35 mm and 75 mm rail.

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

3RT1044-3BD40 — Identification
ParameterValue
Contactor frame sizeS3
3RT1044-3BD40 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated operational current, AC-4 @ 400 V55 A
Rated value @ 400 V3 A
Rated value @ 500 V37 kW
Rated value @ 690 V18.6 kW
Rated value @ 230 V6 A
Rated value @ 24 V10 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT1044-3BD40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT1044-3BD40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1044-3BD40 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusefuse gL/gG: 250 A
Short-circuit coordination type 2, fusefuse gL/gG: 125 A
Aux. switch short-circuit protection, fusefuse gL/gG: 10 A
3RT1044-3BD40 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionspring-loaded terminals
Conductor cross-section, solid2x (0.25 ... 2.5 mm²)
Conductor cross-section, solid or stranded2x (2.5 ... 16 mm²)
Conductor cross-section, finely stranded w/ ferrule2x (0.25 ... 1.5 mm²)
Mounting methodscrew and snap-on mounting onto 35 mm and 75 mm standard mounting rail
Side-by-side mountingYes
3RT1044-3BD40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1044-3BD40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT1044-3BD40 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth152 mm

Product details

What this SIRIUS S3 contactor is rated for

For AC-4 duty (plugging, inching, reversing) it's rated 55 A at 400 V. Those are the numbers that decide fit for a motor control center. At 500 V it handles 37 kW, and at 690 V it's rated 18.6 kW.

The S3 frame size is 70 mm wide, 146 mm high, 152 mm deep — that's the footprint you need to clear in the enclosure. Front protection is IP20 with the cover or box terminal installed; the terminal itself is IP00. That's typical for panel-mount gear — the enclosure provides the real ingress protection.

RoHS compliance is documented with a substance prohibitance date of 05/01/2012, covering the standard EU restricted substances.

Terminal wiring specs

Main circuit terminals accept solid conductors 2x (0.25 to 2.5 mm²) and stranded 2x (10 to 50 mm²), plus 2x (2.5 to 16 mm²) for the solid-or-stranded range. That covers everything from control wiring to heavy motor feeders.

Frequently asked questions

What are the key power ratings for this contactor?

AC-2 duty: 30 kW at 400 V. AC-4 duty: 55 A at 400 V. At 500 V it's rated 37 kW, and at 690 V it's 18.6 kW. The AC-1 maximum operating frequency is 1,000 cycles per hour.

What mounting rail does this contactor fit?

It mounts via screw or snap-on onto both 35 mm and 75 mm standard mounting rails. Side-by-side mounting is permitted without spacing.

What compliance documentation is available for this part?

RoHS compliance is documented with a substance prohibitance date of 05/01/2012. The SIRIUS series typically carries CE, UL, and CSA certifications, though specific approval marks should be verified against the nameplate for your shipment.

MPN
3RT1044-3BD40