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Siemens 3RT2045-1AH20 — Contactors

Siemens 3RT2045-1AH20 SIRIUS Power Contactor, Size S3, 70 mm

MPN3RT2045-1AH20
Active

Siemens SIRIUS power contactor, Size S3, 3RT2045-1AH20, screw and snap-on mounting onto 35 mm DIN rail, 70 mm width, operating temperature -25 to +60 °C, auxiliary switch included.

Siemens 3RT2045-1AH20 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RT2045-1AH20 — Identification
ParameterValue
Contactor frame sizeS3
3RT2045-1AH20 — 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 V2 A
Rated value @ 690 V1 A
Rated value @ 230 V15 hp
Rated value @ 24 V10 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT2045-1AH20 — Control & Coil
ParameterValue
Control supply voltage typeAC
Rated value @ 50 Hz0.35
Rated value @ 50 Hz48 V
3RT2045-1AH20 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT2045-1AH20 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusegG: 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, fusegG: 160A (690V,100kA), aM: 80A (690V,100kA), BS88: 125A (415V,80kA)
Aux. switch short-circuit protection, fusegG: 10 A (500 V, 1 kA)
3RT2045-1AH20 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionscrew-type terminals
Conductor cross-section, solid2.5 ... 16 mm²
Conductor cross-section, solid or stranded2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 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 standard mounting rail according to DIN EN 60715
Side-by-side mountingYes
3RT2045-1AH20 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2045-1AH20 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2045-1AH20 — Mechanical
ParameterValue
Width70 mm
Height140 mm
Depth152 mm
3RT2045-1AH20 — Specifications
ParameterValue
At AC10 ... 21 ms

Product details

SIRIUS Size S3 power contactor — panel fit and switching duty

It carries an auxiliary switch and is rated for continuous operation from -25 to +60 °C. At 70 mm wide, 140 mm tall, and 152 mm deep, it occupies a standard panel footprint. Switching rates vary by duty class: up to 900 cycles/hour at AC-1, 400 at AC-2, 1 000 at AC-3 and AC-3e, and 300 at AC-4. The auxiliary contact is rated at 10 A at 24 V, with lower ratings at higher voltages (e.g., 3 A at 400 V, 0.8 A at 440 V).

Wiring and conductor sizing

Main circuit accepts solid conductors from 2.5 to 16 mm² and stranded from 6 to 70 mm². Auxiliary/control wiring accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded. The magnet coil uses screw-type terminals.

Clearance and storage

Frequently asked questions

Where can I buy 3RT2045-1AH20?

Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.

What are the key dimensions of 3RT2045-1AH20?

Width 70 mm, height 140 mm, depth 152 mm. It mounts on 35 mm DIN rail per DIN EN 60715 with screw and snap-on fastening.

What conductor sizes does 3RT2045-1AH20 accept?

Solid conductors 2.5 to 16 mm² for the main circuit; stranded 6 to 70 mm². Auxiliary/control wiring accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²).

What is the auxiliary contact rating on 3RT2045-1AH20?

10 A at 24 V rated value, with lower ratings at higher voltages: 2 A at 48 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, and 0.8 A at 440 V.

MPN
3RT2045-1AH20