Siemens SIRIUS S3 power contactor, 3RT1044-3BB40, 24 VDC coil, 10 A at 24 VDC, screw-type terminals, 70 x 146 x 152 mm (WxHxD).
| Parameter | Value |
|---|---|
| Contactor frame size | S3 |
| Parameter | Value |
|---|---|
| Rated operational current, AC-12, max. | 10 A |
| Rated operational current, AC-4 @ 400 V | 55 A |
| Rated value @ 400 V | 3 A |
| Rated value @ 500 V | 37 kW |
| Rated value @ 690 V | 18.6 kW |
| Rated value @ 230 V | 6 A |
| 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 |
| Parameter | Value |
|---|---|
| Control supply voltage type | DC |
| Parameter | Value |
|---|---|
| Main poles | 3 |
| Main NO contacts | 3 |
| Auxiliary contact reliability | 1 faulty switching per 100 million (17 V, 1 mA) |
| Parameter | Value |
|---|---|
| Short-circuit coordination type 1, fuse | fuse gL/gG: 250 A |
| Short-circuit coordination type 2, fuse | fuse gL/gG: 125 A |
| Aux. switch short-circuit protection, fuse | fuse gL/gG: 10 A |
| Parameter | Value |
|---|---|
| Main circuit connection | screw-type terminals |
| Aux. / control circuit connection | spring-loaded terminals |
| Conductor cross-section, solid | 2x (0.25 ... 2.5 mm²) |
| Conductor cross-section, solid or stranded | 2x (2.5 ... 16 mm²) |
| Conductor cross-section, finely stranded w/ ferrule | 2x (0.25 ... 1.5 mm²) |
| Mounting method | screw and snap-on mounting onto 35 mm and 75 mm standard mounting rail |
| Side-by-side mounting | Yes |
| Parameter | Value |
|---|---|
| Durability (operating cycles, typ.) | 10 000 000 |
| Durability with aux. switch block (cycles, typ.) | 10 000 000 |
| Parameter | Value |
|---|---|
| Operating temperature range | -25 ... +60 °C |
| Storage temperature range | -55 ... +80 °C |
| Installation altitude, max. | 2 000 m |
| Parameter | Value |
|---|---|
| Width | 70 mm |
| Height | 146 mm |
| Depth | 152 mm |
The Siemens 3RT1044-3BB40 is a SIRIUS S3 power contactor. It carries a 24 VDC coil rated at 10 A at 24 VDC.
At 60 VDC the switching capacity drops to 2 A, and at 220 VDC it's 0.3 A, so this is a low-voltage DC coil, not a high-voltage DC power contactor. The AC-3 maximum operating rate is 1 000 cycles per hour, which covers most conveyor and pump cycles without thermal buildup.
The S3 frame measures 70 mm wide by 146 mm high by 152 mm deep. Side-by-side mounting is allowed.
The solid conductor capacity for the main terminals is 2x (0.25... 2.5 mm²) — that's two solid wires per clamp, each between 0.25 and 2.5 mm² cross-section. For stranded conductors the range is 2x (10... 50 mm²), so you can land larger flexible cables with ferrules.
The physical footprint (S3 frame, 70 x 146 x 152 mm) and DIN-rail mounting are identical, so the mechanical fit is the same. However, the coil voltage differs — the 3RT1044-1FB46 uses a different coil rating — so you must verify the control voltage matches. The main terminal sizes and screw-type connection are similar, but check the auxiliary contact configuration because the 1FB46 variant may have a different auxiliary block.
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