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Siemens 3RT5045-1BW40 — Contactors

Siemens 3RT5045-1BW40 SIRIUS S3 Power Contactor, 48 V DC Coi

MPN3RT5045-1BW40

Siemens SIRIUS S3 power contactor, 3RT5045-1BW40, 48 V DC coil, screw-type terminals, 114 kW at 690 V at 60 °C, snap-on DIN rail 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

3RT5045-1BW40 — Identification
ParameterValue
Contactor frame sizeS3
3RT5045-1BW40 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated value @ 400 V3 A
Rated value @ 690 V21.1 kW
Rated value @ 230 V6 A
Rated value @ 24 V6 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT5045-1BW40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT5045-1BW40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT5045-1BW40 — 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
3RT5045-1BW40 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionscrew-type terminals
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
3RT5045-1BW40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT5045-1BW40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT5045-1BW40 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth152 mm

Product details

The 3RT5045-1BW40: Rated for 114 kW at 690 V at 60 °C ambient, this contactor handles heavy motor loads in conveyor, pump, and fan applications. The S3 frame size and screw-type main terminals accept up to 2x 16 mm² solid/stranded or 2x 1/0 AWG, matching typical panel wiring for 50–100 A motor circuits. The 48 V DC coil draws 15 W closing and holding, so the control transformer or DC supply must be sized for that continuous draw. At 24 V DC the coil draws 6 A inrush; verify your PLC output or relay can handle that peak.

Snap-on mounting onto 35 mm or 75 mm standard DIN rail, plus screw fixing for vibration-prone environments. Width is 70 mm, depth 152 mm, height 146 mm — the S3 footprint.

Coordination and compliance

This matters for selectivity studies — the contactor clears faults without damage up to that fuse rating, so it coordinates with standard motor branch circuits. Insulation voltage rated 1000 V gives headroom for 690 V systems. RoHS compliance date is March 1, 2017 — the part meets EU substance restrictions. Auxiliary switch extension is supported via the SIRIUS add-on system, so you can add feedback contacts without changing the base contactor.

Switching performance

Electrical life varies by duty: AC-1 (resistive) at 900 cycles/hour, AC-3 (motor start/run) at 1000 cycles/hour, AC-4 (plugging/inching) at 300 cycles/hour. At 690 V the contactor switches 21.1 kW motor load; at 400 V 66 kW; at 230 V 38 kW — all at 60 °C ambient. These are the real-world ratings for sizing, not just the maximum voltage number.

Frequently asked questions

What is the closest functional alternative to 3RT5045-1BW40?

The 3RT5045-1AC20 uses an AC coil instead of the 48 V DC coil on the -1BW40. The 3RT5045-1AF00 uses a different control voltage. The 3RT5046-1BM40 is a larger S3 frame variant. For a DC coil replacement at the same frame size, the -1BW40 is the direct choice — swapping to an AC coil version would require control circuit rewiring.

Where can I buy 3RT5045-1BW40 and how is it quoted?

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 volume and delivery requirements.

Will 3RT5045-1BW40 drop into a panel specified for 3RT5045-1AC20?

The physical dimensions and mounting are identical — both are S3 frame with the same 70 mm width, 152 mm depth, and DIN rail snap-on. The difference is the coil: the -1BW40 requires 48 V DC, while the -1AC20 uses an AC coil. If the control circuit supplies 48 V DC, it drops in without rewiring.

What compliance documentation does Siemens provide for 3RT5045-1BW40?

The part is RoHS compliant with a substance prohibition date of March 1, 2017. Pollution degree 3 and insulation voltage 1000 V indicate IEC 60947 compliance. Standard Siemens documentation includes the datasheet, CE declaration, and REACH information upon request.

MPN
3RT5045-1BW40