The Siemens 3RT2045-1KB40 is a SIRIUS S3 coupling contactor rated for 24 V DC coil voltage, with screw-type terminals and a mechanical life of 10 million operations. It snaps onto 35 mm DIN rail per DIN EN 60715 and accepts solid conductors from 2.5 to 16 mm² or stranded from 6 to 70 mm². Dimensions are 70 mm wide, 140 mm high, and 152 mm deep, with mounting position flexibility of +/-180° rotation on a vertical surface and +/-22.5° tilt forward or backward. Switching frequency at AC-3 duty reaches 1 000 operations per hour; at AC-1 it's 900 per hour. Operating temperature range is -25 to +60 °C.
Siemens 3RT2045-1KB40 SIRIUS Coupling Contactor, 24V DC, S3
MPN3RT2045-1KB40
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Siemens SIRIUS S3 coupling contactor, 3RT2045-1KB40, 24 V DC coil, screw-type terminals, DIN rail mounting, 10 million mechanical cycles.
$191.77 – $460.85Ref. price · indicative, final on quote
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MOQ1 pcs
Sourced new & surplus through independent channelsListing updated Jun 2026
Specifications
Identification
| Parameter | Value |
|---|---|
| Contactor frame size | S3 |
Ratings & Performance
| Parameter | Value |
|---|---|
| Rated operational current, AC-12, max. | 10 A |
| Rated operational current, AC-4 @ 400 V | 66 A |
| Rated value @ 400 V | 3 A |
| Rated value @ 500 V | 2 A |
| Rated value @ 690 V | 1 A |
| Rated value @ 230 V | 15 hp |
| Rated value @ 24 V | 10 A |
| Rated value @ 60 V | 2 A |
| Rated value @ 110 V | 1 A |
| Rated value @ 220 V | 0.3 A |
Control & Coil
| Parameter | Value |
|---|---|
| Control supply voltage type | DC |
Contacts & Poles
| Parameter | Value |
|---|---|
| Main poles | 3 |
| Main NO contacts | 3 |
| Auxiliary contact reliability | 1 faulty switching per 100 million (17 V, 1 mA) |
Protection & Coordination
| Parameter | Value |
|---|---|
| Short-circuit coordination type 1, fuse | gG: 250 A (690 V, 100 kA), aM: 160 A (690 V, 100 kA), BS88: 200 A (415 V, 80 kA) |
| Short-circuit coordination type 2, fuse | gG: 160A (690V,100kA), aM: 80A (690V,100kA), BS88: 125A (415V,80kA) |
| Aux. switch short-circuit protection, fuse | gG: 10 A (500 V, 1 kA) |
Connection & Mounting
| Parameter | Value |
|---|---|
| Main circuit connection | screw-type terminals |
| Aux. / control circuit connection | screw-type terminals |
| Conductor cross-section, solid | 2.5 ... 16 mm² |
| Conductor cross-section, solid or stranded | 2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²) |
| Conductor cross-section, finely stranded w/ ferrule | 2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²) |
| Mounting method | screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715 |
| Side-by-side mounting | Yes |
Durability
| Parameter | Value |
|---|---|
| Durability (operating cycles, typ.) | 10 000 000 |
| Durability with aux. switch block (cycles, typ.) | 10 000 000 |
Environmental
| Parameter | Value |
|---|---|
| Operating temperature range | -25 ... +60 °C |
| Storage temperature range | -55 ... +80 °C |
| Installation altitude, max. | 2 000 m |
Mechanical
| Parameter | Value |
|---|---|
| Width | 70 mm |
| Height | 140 mm |
| Depth | 152 mm |
Specifications
| Parameter | Value |
|---|---|
| At AC | 16.3g / 5 ms, 10.g / 10 ms |
Product details
Frequently asked questions
What conductor cross-sections does the 3RT2045-1KB40 accept?
Solid wire from 2.5 to 16 mm² and stranded wire from 6 to 70 mm².
MPN
3RT2045-1KB40