Siemens 3RT2025-2KB40 SIRIUS Contactor, 24 VDC Coil
Siemens SIRIUS 3RT2025-2KB40 coupling contactor, S0 frame size, 24 VDC coil, spring-type terminals, 45 x 102 x 107 mm (WxHxD).
Specifications
| Parameter | Value |
|---|---|
| Contactor frame size | S0 |
| Parameter | Value |
|---|---|
| Rated operational current, AC-12, max. | 10 A |
| Rated operational current, AC-4 @ 400 V | 15.5 A |
| Rated value @ 400 V | 3 A |
| Rated value @ 500 V | 2 A |
| Rated value @ 690 V | 1 A |
| Rated value @ 230 V | 3 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 |
| 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 | gG: 63A (690V,100kA), aM: 32A (690V,100kA), BS88: 63A (415V,80kA) |
| Short-circuit coordination type 2, fuse | gG: 25A (690V,100kA), aM: 20A (690V,100kA), BS88: 25A (415V,80kA) |
| Aux. switch short-circuit protection, fuse | gG: 10 A (500 V, 1 kA) |
| Parameter | Value |
|---|---|
| Main circuit connection | spring-loaded terminals |
| Aux. / control circuit connection | spring-loaded terminals |
| Conductor cross-section, solid | 1 ... 10 mm² |
| Conductor cross-section, solid or stranded | 2x (0.5 ... 2.5 mm²) |
| Conductor cross-section, finely stranded w/ ferrule | 2x (0.5 ... 1.5 mm²) |
| Mounting method | screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715 |
| 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 | 45 mm |
| Height | 102 mm |
| Depth | 107 mm |
Product details
DC switching capacity and operating limits
The 3RT2025-2KB40: At its rated 24 VDC coil voltage, the main contacts switch 10 A. This derating curve is typical for DC switching — the arc extinction limits the current as voltage rises. The coil operates between 0.7 and 1.25 times its rated value, so at 24 VDC nominal the pickup range is roughly 16.8 V to 30 V. Mechanical switching frequency reaches 1,000 operations per hour under AC-1, AC-2, AC-3, and AC-3e duty, dropping to 300 per hour under AC-4. The contactor carries a typical mechanical service life of 10 million operations. No auxiliary switch is included on this variant — if you need auxiliary contacts, they must be added separately.
Clearance distances are specified: 10 mm upwards, forwards, and downwards, with 6 mm at the sides. The arcing time is 10 ms, and the DC operating time (coil pickup to main contact closure) is 19 to 21 ms. These figures matter when coordinating with PLC scan cycles or safety circuit timing.