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Siemens 3RT1044-1BM40 — Contactors

Siemens 3RT1044-1BM40 SIRIUS Power Contactor, Size S3, 37 kW

MPN3RT1044-1BM40

Siemens SIRIUS power contactor, size S3, 3RT1044-1BM40, 37 kW at 500 V, screw-type terminals, 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

3RT1044-1BM40 — Identification
ParameterValue
Contactor frame sizeS3
3RT1044-1BM40 — 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
3RT1044-1BM40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT1044-1BM40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1044-1BM40 — 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
3RT1044-1BM40 — 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
3RT1044-1BM40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1044-1BM40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT1044-1BM40 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth152 mm

Product details

SIRIUS Power Contactor, Size S3 — 3RT1044-1BM40

The Siemens 3RT1044-1BM40 is a SIRIUS power contactor in size S3, rated for 37 kW at 500 V and 18.6 kW at 690 V, making it suitable for switching three-phase motor loads in industrial control panels. It mounts via screw or snap-on onto 35 mm or 75 mm standard mounting rail, and the main current circuit uses screw-type terminals accepting solid conductors up to 2x (0.5...1.5 mm²) or stranded up to 2x (10...50 mm²).

Side-by-side mounting is permitted, so multiple units can be ganged without additional spacing.

Terminal & Wiring

Screw-type terminals on the main circuit accept solid conductors: 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), max. 2x (0.75...4 mm²). Stranded conductors: 2x (10...50 mm²). The auxiliary circuit terminals accept 2x (2.5...16 mm²) solid or stranded.

Frequently asked questions

How do I get current pricing and availability for 3RT1044-1BM40?

Submit an RFQ through this listing; the part is sourced to order through independent distribution, and availability and current pricing are confirmed at quote time.

Will 3RT1044-1BM40 drop into a panel specified around 3RT1044-1FB46 without rewiring?

The 3RT1044-1BM40 and 3RT1044-1FB46 share the same SIRIUS S3 frame size and mounting footprint (snap-on 35/75 mm rail), so mechanical fit is identical. The key difference is the coil voltage: the -1BM40 uses a 220 V AC coil, while the -1FB46 uses a different coil voltage — verify the control circuit before substitution.

MPN
3RT1044-1BM40