Skip to main content
Siemens 3RT1045-1BF40 — Contactors

Siemens 3RT1045-1BF40 SIRIUS Power Contactor, 110 V Coil, Si

MPN3RT1045-1BF40

Siemens SIRIUS power contactor, 3RT1045-1BF40, size S3, 110 V AC coil, screw-type terminals, IP20 front, 70 mm width, 146 mm height, 152 mm depth.

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

3RT1045-1BF40 — Identification
ParameterValue
Contactor frame sizeS3
3RT1045-1BF40 — 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
3RT1045-1BF40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT1045-1BF40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1045-1BF40 — 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
3RT1045-1BF40 — 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
3RT1045-1BF40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1045-1BF40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT1045-1BF40 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth152 mm

Product details

SIRIUS S3 Power Contactor, 110 V Coil

Rated for AC-3 switching at 500 V delivering 45 kW, and at 690 V delivering 21.1 kW, this contactor handles motor loads typical of pumps, fans, and compressors in industrial control panels. Mechanical life is rated at 10 million operations typical, with maximum switching rates of 1000 cycles per hour in AC-3 duty, 900 in AC-1, 400 in AC-2, and 300 in AC-4.

Main circuit terminals accept solid conductors from 2x (0.5 to 1.5 mm²) up to 2x (0.75 to 4 mm²) and stranded conductors from 2x (10 to 50 mm²); auxiliary terminals accept 2x (2.5 to 16 mm²) solid or stranded. The terminal block itself carries an IP00 rating, so the overall IP20 protection on the front relies on the cover or box terminal being fitted — plan for panel-side sealing if the contactor is mounted in a washdown or dusty environment.

Pollution degree 3 classification means it is suited for industrial atmospheres with conductive pollution. Lifecycle status is current production. RoHS compliance date is 05/01/2012, covering substance prohibitions under EU Directive 2011/65/EU. DC switching times are 14 to 20 ms. These figures matter when coordinating with upstream protection devices or when the contactor is used in a safety circuit requiring fast dropout.

Frequently asked questions

What is 3RT1045-1BF40's listed depth?

The depth is 152 mm, with a width of 70 mm and height of 146 mm, making it a size S3 footprint that fits standard DIN-rail enclosures.

What solid wire sizes does 3RT1045-1BF40 accept?

The main terminals accept solid conductors in ranges of 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and a maximum of 2x (0.75 to 4 mm²). Stranded conductors up to 2x (10 to 50 mm²) are also supported.

What compliance documentation does Siemens provide for 3RT1045-1BF40?

The contactor is RoHS compliant with a substance prohibition date of 05/01/2012. The SIRIUS series typically carries UL, CSA, and CE certifications; specific approval markings should be verified against the nameplate on the unit.

Where can I buy 3RT1045-1BF40?

This part is sourced and quoted to order against an RFQ through independent distribution channels. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time.

MPN
3RT1045-1BF40