77 A at 480 V — AC-3 motor switching
The 3RT2045-1AB00: Size S3 frame with screw-type main terminals accepting 6 to 70 mm² stranded wire — the lug capacity matches the 77 A rating without needing a separate terminal adapter.

Siemens SIRIUS 3RT2045-1AB00 power contactor, Size S3, 77 A at 480 V AC-3, 3-pole, screw-type terminals, 35 mm DIN rail mount.
| Parameter | Value |
|---|---|
| Contactor frame size | S3 |
| 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 | 6 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 | AC |
| Rated value @ 50 Hz | 0.38 |
| Rated value @ 50 Hz | 24 V |
| 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: 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) |
| 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 |
| 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 | 140 mm |
| Depth | 152 mm |
| Parameter | Value |
|---|---|
| At AC | 10 ... 21 ms |
The 3RT2045-1AB00: Size S3 frame with screw-type main terminals accepting 6 to 70 mm² stranded wire — the lug capacity matches the 77 A rating without needing a separate terminal adapter.
77 A in AC-3 duty at 480 V — that's the motor-switching current for loads like pumps and conveyors up to about 37 kW.
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Alternative models and sibling configurations in the same Siemens series. For obsolete or discontinued parts, these models can serve as compatible replacements or functional alternatives for plant maintenance.
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