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Siemens 3RT1044-1BB44-3MA0 — Contactors

Siemens SIRIUS 3RT1044-1BB44-3MA0 Power Contactor, AC-4 55 A

MPN3RT1044-1BB44-3MA0

Siemens SIRIUS power contactor, 3RT1044-1BB44-3MA0, S3 size, 55 A AC-4 at 400 V, 37 kW at 500 V, screw terminals, DIN-rail mount, IP20 front.

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

3RT1044-1BB44-3MA0 — Identification
ParameterValue
Contactor frame sizeS3
3RT1044-1BB44-3MA0 — 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
3RT1044-1BB44-3MA0 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT1044-1BB44-3MA0 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1044-1BB44-3MA0 — 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
3RT1044-1BB44-3MA0 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionscrew-type terminals
Conductor cross-section, solid2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 mm²)
Conductor cross-section, solid or stranded2x (2.5 ... 16 mm²)
Conductor cross-section, finely stranded w/ ferrule2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)
Mounting methodscrew and snap-on mounting onto 35 mm and 75 mm standard mounting rail
Side-by-side mountingYes
3RT1044-1BB44-3MA0 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1044-1BB44-3MA0 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT1044-1BB44-3MA0 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth201 mm

Product details

Its AC-4 rating at 55 A at 400 V means it handles the severe inrush and breaking duty of reversing or plugging applications — the kind of service that cycles a motor from forward to stop to reverse without a coasting delay. For AC-2 duty (starting and stopping slip-ring motors), it is rated at 30 kW at 400 V. The AC-3 rating supports 37 kW at 500 V, covering the bulk of standard squirrel-cage motor starts.

Terminal and Environmental Ratings

The main current circuit uses screw-type terminals, accepting solid conductors up to 2x (0.5... 1.5 mm²) or 2x (0.75... 2.5 mm²), and stranded conductors up to 2x (10... 50 mm²). The contactor is rated IP20 on the front with a cover or box terminal; the terminal body itself is IP00, so the panel enclosure provides the overall ingress protection.

Coil and Auxiliary Contact Ratings

The coil is rated at 24 V DC, drawing 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. The contactor's mechanical life is typically 10,000,000 operations.

Frequently asked questions

What compliance documentation does this contactor carry?

The part is RoHS and REACH compliant, with a substance prohibition date of 05/01/2012. The manufacturer provides a declaration of conformity covering the relevant EU directives.

What is the closest functional alternative if 3RT1044-1BB44-3MA0 is unavailable?

The 3RT1036-1AB00 is a smaller S2 frame contactor but shares the same SIRIUS platform and screw-terminal design. However, it has lower AC-3 and AC-4 ratings — verify the motor full-load current and duty cycle before substituting. The 3RT1044-1BB44-3MA0 is the correct fit for the S3 frame and the 55 A AC-4 rating.

MPN
3RT1044-1BB44-3MA0