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Siemens 3RT1045-1AL24 — Contactors

Siemens 3RT1045-1AL24 SIRIUS Power Contactor, 45 kW at 500 V

MPN3RT1045-1AL24

Siemens SIRIUS 3RT1045-1AL24 power contactor, S3 frame, 45 kW at 500 V AC-3, screw-type terminals, 24 V DC coil, DIN rail mount.

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

3RT1045-1AL24 — Identification
ParameterValue
Contactor frame sizeS3
3RT1045-1AL24 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated operational current, AC-4 @ 400 V66 A
Rated value @ 400 V3 A
Rated value @ 500 V45 kW
Rated value @ 690 V21.1 kW
Rated value @ 230 V6 A
Rated value @ 24 V10 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT1045-1AL24 — Control & Coil
ParameterValue
Control supply voltage typeAC
Rated value @ 50 Hz0.8 ... 1.1
Rated value @ 50 Hz230 V
3RT1045-1AL24 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1045-1AL24 — 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
3RT1045-1AL24 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionscrew-type terminals
Conductor cross-section, solid2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 mm²)
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
3RT1045-1AL24 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1045-1AL24 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT1045-1AL24 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth188 mm
3RT1045-1AL24 — Specifications
ParameterValue
At AC10 ... 25 ms

Product details

Its headline rating is 45 kW at 500 V under AC-3 duty (cite:), which means it handles the inrush and breaking of squirrel-cage motors up to that power level — the rating that governs real-world motor switching, not the higher resistive-load figure. The 24 V DC coil (cite:) draws 10 A at rated voltage, so verify your control transformer and fuse sizing against that pickup current. Mechanical endurance is listed at 10,000,000 operations typical (cite:), which for a contactor on a conveyor or pump running 100 cycles per hour gives about 11 years of service before mechanical wear becomes a concern. The AC-3 maximum switching rate of 1,000 operations per hour (cite:) sets the thermal limit for the arc chamber — sustained cycling above that rate accelerates contact erosion.

The S3 frame occupies 70 mm width, 146 mm height, and 188 mm depth (cite:,) — check your backpanel gland plate clearance, especially if the contactor sits near the enclosure wall. Side-by-side mounting is permitted (cite:), which saves rail space but requires attention to thermal derating if multiple contactors are ganged without spacing. Main circuit connections are screw-type terminals (cite:). Solid wire capacity is 2x (0.5... 1.5 mm²) and 2x (0.75... 2.5 mm²), max 2x (0.75... 4 mm²) (cite:); stranded accepts 2x (10... 50 mm²) (cite:). The IP20 rating on the front with cover or box terminal (cite:) means the contactor is finger-safe from the front but not sealed — suitable for enclosed panels, not washdown zones.

Frequently asked questions

What are the key motor ratings for this contactor?

The AC-3 motor rating is 45 kW at 500 V (cite:). At 690 V it is rated for 21.1 kW (cite:). These are the figures that determine fit for a given motor load — use the AC-3 value, not the resistive AC-1 rating, when sizing for induction motors.

What is the operating temperature range?

During operation it is rated from -25 °C to +60 °C (cite:). Storage range is -55 °C to +80 °C (cite:). The operating limit matters for panel ambient; if your enclosure hits 60 °C internal, the contactor is still in spec without derating.

Does this contactor mount on standard DIN rail?

Yes, it fastens via screw or snap-on onto 35 mm and 75 mm standard mounting rails (cite:). Side-by-side mounting is allowed (cite:), which is useful for multi-contactor motor starter assemblies.

MPN
3RT1045-1AL24