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Siemens 3RT1045-1BB40 — Contactors

Siemens 3RT1045-1BB40 SIRIUS Power Contactor, 24 VDC Coil, S

MPN3RT1045-1BB40

Siemens SIRIUS power contactor, size S3, 24 VDC coil, screw-type terminals, 45 kW at 500 V AC-3, 70 mm width, snap-on mounting.

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

3RT1045-1BB40 — Identification
ParameterValue
Contactor frame sizeS3
3RT1045-1BB40 — 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
3RT1045-1BB40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT1045-1BB40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1045-1BB40 — 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
3RT1045-1BB40 — 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
3RT1045-1BB40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1045-1BB40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT1045-1BB40 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth152 mm

Product details

Its 24 V DC coil (rated value 24 V) picks up at 0.8 x Us and drops out at 1.1 x Us, with a DC arcing time of 14 to 20 ms and an AC arcing time of 10 to 15 ms — the DC arcing characteristic matters when breaking inductive DC loads, where the arc extinguishes slower than on AC. Rated for AC-3 duty at 45 kW on 500 V and 21.1 kW on 690 V, this contactor handles the motor starting and running currents typical of pumps, fans, and compressors in the 30–60 hp range on 400 V systems.

Main circuit terminals are screw-type, accepting solid conductors 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²), and stranded conductors 2x (10 to 50 mm²) and 2x (2.5 to 16 mm²). The IP20 rating on the front with cover or box terminal means the contactor is finger-safe once installed in an enclosure; the terminal body itself is IP00, so live parts are exposed until the enclosure door is closed.

The substance prohibition date of 05/01/2012 aligns with RoHS compliance; expect REACH and RoHS documentation with the shipment.

DC Switching Capability

The contactor is rated for DC switching at several voltage levels: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. These ratings are for resistive DC loads; inductive DC loads (solenoids, DC motor brakes) require derating or arc-suppression measures because the DC arcing time of 14 to 20 ms is longer than the AC arcing time.

Mechanical Endurance

Typical mechanical life is 10 000 000 operations. Electrical life depends on the duty cycle: AC-1 (resistive) allows 900 operations per hour, AC-2 (slip-ring motors) 400 ops/h, AC-3 (squirrel-cage motors) 1 000 ops/h, and AC-4 (reversing/inching) 300 ops/h. The mechanical life figure means the contactor itself will outlast most motor-driven equipment in normal service.

Frequently asked questions

Where can I buy 3RT1045-1BB40 and what is the lead time?

This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for your quantity and timeline.

What is the depth of 3RT1045-1BB40?

The depth is 152 mm. Combined with the width of 70 mm and height of 146 mm, the contactor fits standard panel layouts and leaves clearance for wiring ducts and cable bends.

What compliance documentation does Siemens provide for 3RT1045-1BB40?

The part has a substance prohibition date of 05/01/2012, indicating RoHS compliance. Expect RoHS and REACH declarations with the shipment. The IP20 front rating and pollution degree 3 classification support UL and IEC listing for industrial control equipment.

MPN
3RT1045-1BB40