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Siemens 3RT1045-1AB04 — Contactors

Siemens 3RT1045-1AB04 SIRIUS Power Contactor, 37 kW AC-2 at

MPN3RT1045-1AB04

Siemens SIRIUS 3RT1045-1AB04, size S3 power contactor, 37 kW AC-2 at 400 V, 66 A AC-4, screw-type terminals, screw and snap-on 35/75 mm rail mounting, current production.

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

3RT1045-1AB04 — Identification
ParameterValue
Contactor frame sizeS3
3RT1045-1AB04 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated operational current, AC-4 @ 400 V66 A
Rated value @ 400 V3 A
Rated value @ 500 V45 kW
Rated value @ 690 V21.1 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
3RT1045-1AB04 — Control & Coil
ParameterValue
Control supply voltage typeAC
Rated value @ 50 Hz0.8 ... 1.1
Rated value @ 50 Hz24 V
3RT1045-1AB04 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1045-1AB04 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusefuse gL/gG: 250 A
Short-circuit coordination type 2, fusefuse gL/gG: 160 A
Aux. switch short-circuit protection, fusefuse gL/gG: 10 A
3RT1045-1AB04 — 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
3RT1045-1AB04 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1045-1AB04 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT1045-1AB04 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth188 mm
3RT1045-1AB04 — Specifications
ParameterValue
At AC10 ... 25 ms

Product details

Mounting and termination

The 3RT1045-1AB04: Mounts via screw or snap-on onto standard 35 mm or 75 mm DIN rail — the 70 mm width means it occupies three 22.5 mm module spaces in a panel. That stranded capacity is generous for the S3 frame; you can land heavy motor cables without a ferrule if the lug is crimped.

The front terminals carry IP20 (finger-safe with cover), the terminal body is IP00. RoHS compliance substance prohibition date is May 1, 2012, covering the standard EU restricted substances.

Frequently asked questions

What are the key motor ratings for this contactor?

AC-2 at 400 V: 37 kW for slip-ring motor starting. AC-4 at 400 V: 66 A for plugging and inching. AC-3 maximum switching rate is 1 000 operations per hour; AC-4 maximum is 300 per hour. The coil is 24 V at 50 Hz.

Will the 3RT1045-1AB04 drop into a panel wired for a 3RT1036-1AB00?

Not without checking the footprint. The 3RT1045 is a size S3 frame (70 mm wide, 146 mm tall, 188 mm deep), while the 3RT1036 is a smaller S2 or S0 frame. The mounting rail pitch and terminal positions differ — you would need to verify the DIN space and re-land the power wiring for the larger terminal capacity.

What compliance documentation is available for this contactor?

RoHS compliance with substance prohibition date of May 1, 2012. The SIRIUS series carries IEC/EN 60947-4-1 certification for contactors and motor starters. Specific UL/CSA file numbers are not listed in this evidence, but the SIRIUS line is typically UL-listed; verify the exact UL marking on the unit for your jurisdiction.

MPN
3RT1045-1AB04